Refrigeration, air-conditioning and cooling technology - 2007.pdf

PLH_Titel_KKK.qxd 25.05.2007 10:21 Uhr Seite 2Refrigeration,air-conditioning andcooling technologyPlanning Guide2007

PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 2C ONTENTSFundamentals of refrigeration, air-conditioning and cooling technology 5Pump curves 6Suction behaviour of the centrifugal pump 9Pump efficiency 11Power requirements of the pump 12Pressure behaviour 14Pumping of viscous media 15Noises – Airborne sound – Structure-borne sound 19Pumps as noise generators 19Airborne sound 20Structure-borne sound and waterborne sound 20Measures against noises 21Pump inlet 29Pump sump 29Suction lines and suction tanks 30Suctioning 31Pump performance control 33Control mode ∆p-c 33Control mode ∆p-v 34Differential pressure – delivery-superimposed (∆p-q) 34Control mode ∆p-T 35Operating mode DDC 35Generator circuits in the liquefier part 37Cooling tower / emergency cooler 37Heat recovery 38Geothermal power in the condenser circuit 39Generator circuits in the vaporiser part 41Constant volume flow in the vaporiser circuit 41Variable volume flow in the vaporiser circuit 42Cold-water loads 43Protection of pumps and refrigerating machines 47Minimum run-time of refrigeration generators and buffer mode 47Protection of the refrigerating machine in the vaporiser circuit 49Protection of the refrigerating machine in the condenser circuit 49Protection of circulating pumps 50Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 3C ONTENTSExamples for the pump selection in the condenser circuit 57Well system 57Open cooling tower system 59Closed cooling tower system 61Heat recovery via building heating and hot water production 63Ground collector system 65Ground spike system 67Examples for the pump selection in the cold water circuit 68Flow rate control with straight-through valves 68Flow rate control with distributor valve 70Admixing circuit for temperature control 72Examples for the pump selection in the vaporiser circuit 74Vaporiser circuit with constant volume flow 74Hydraulic decoupler in vaporiser circuit 75Vaporiser circuit with ice storage 76Vaporiser circuit with variable volume flow 78Economical consideration in the selection of fittings 83Appendix 86Seminars 98Information material 99Imprint 103Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007

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PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 5Fundamentals of refrigeration,air-conditioning and cooling technologyThe transportation of refrigeration, air-conditioning and cooling fluid plays an importantrole inside of buildings. Cold water is pumped for cooling work machines in industryand to the vaporiser in building engineering. Air-conditioners require fluids forheat transport and utilise the active force of circulating pumps for faster exchangeand short regulation times. In cooling towers, fluids are pumped with and withoutfluid processing for accomplishing tasks.Fluid heat transfer media require pumps and systems for transport, which meet thevarious chemical, physical, mechanical and financial requirements.The contents of this brochure should give peoplewho are being trained or getting additionaltraining basic knowledge of system design.Different designs and versions of systems withliquid heat transfer media can bring about directramifications due to irritating noise generationor component failure. The user should be givenan adequate practical basis with simple explanations,drawings and examples. The selection andappropriate use of pumps with their accessoriesin refrigeration, air-conditioning and coolingtechnology should become daily routine.It is to be considered that various standards(EN, DIN, VDE, ISO, IEC) and directives(VDI, DVGW, ATV, VDMA) are to be compliedwith and special aggregates and techniquesselected. National building regulations and environmentalprotection directives, etc. pose additionaldemands. The basic requirements aretaken into consideration in this brochure. Sincerequirements are constantly changing, additionalinformation channels with the newest stateof the art must flow into system planning everyday. This cannot be achieved with the contentsof this brochure.Please observe the further option for increasingyour knowledge based on this planning guide forrefrigeration, air-conditioning and cooling systemsby using our documentation and informationmaterials. We have compiled an up-to-dateoverview. Here you will find documents whichyou can read on your own and our seminar programwith practical training.Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 5

PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 6FUNDAMENTALSPump curvesSystem curveSystem curveDelivery head H [m]System curveH AH VL+ H VAThe system curve indicates the delivery head H Arequired by the system. It consists of the componentsH geo , H VL and H VA . While H geo (static) remainsconstant independent of the volume flow,H VL and H VA (dynamic) increase quadratically dueto the widely varying losses in the pipelines andfittings, as well as due to increased friction, etc.due to temperature influences.H GesAbbreviation DescriptionH AH VLH VAH geoH GesSystem curveRequired delivery head of the systemPressure losses in the pipelinesPressure losses in the fittingsStatic head difference(static head difference to beovercome)Total head lossesThe static components consist of the geodeticpart which is independent of flow H geo and thepressure head differencep a - p eρ · gbetween the entry and exit cross-section of thesystem.This last component is omitted in the case ofopen tanks. The dynamic components consistof the pump head loss H V , which increases quadraticallywith increasing flow, and the differencein the velocity headsv a2 - v e22 · gH geoFlow Q [m³/h]out of the entry and exit cross-section of thesystem.H [m]80706050403020100Resistance changes quadradically with flow H 2 Q 2H 1 Q 12=Delivery head H Aof the system [m]Abbreviationv av ep ap eρgH VH 1Q 1H 2Q 20 1 2 3 4DescriptionExit speedEntry speedExit pressureEntry pressureFluid densitySystem curve HADynamic part = H V +Static part = H geo +Gravitational accelerationPressure loss in the pipeworkQ [m 3 /h]v a 2 - v e22 · gp a- p eρ · gFlow Q [m³/h]6 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 7FUNDAMENTALSPump curveThe flow rate of a centrifugal pump is specifiedby a pump curve in the Q vs. H diagram. In this,the flow Q is plotted, for example, in m 3 /h andthe pump delivery head H in m.The pump curve is curvilinear and drops in thediagram with increasing flow from left to right.The gradient of the pump curve is determinedby the pump design and also specifically by theconstruction form of the impeller. Every changein the delivery head always results in a change inflow.The characteristic property of the pump curve isthe mutual dependence of the flow on the deliveryhead.Delivery head H [m]Pump curvePump curveSystem curveIntersectionpoint =duty pointFlow Q [m 3 /h]The pump delivery head isalways as high as the flowresistance of the pipelinesystem.High flow ^- low delivery head,low flow ^- high delivery head.Although the installed pipeline system exclusivelyspecifies which flow is pumped at thegiven pump capacity due to the internal resistances,the pump in question can always take ononly one duty point on its curve. This duty pointis the intersection of the pump curve with therespective system curve.Duty pointThe duty point is the intersection of the systemcurve and the pump curve. The duty point adjustsitself independently in pumps with a fixedspeed.A change in the duty point occurs when, for example,in the case of a stationary pump station,the geodetic delivery head fluctuates betweenthe maximum and minimum values. Due to this,the delivered volume flow of the pump changessince this can only take on duty points on thepump curve.Delivery head H [m]Fluctuating water level in the tankPump curveSystem curve 2System curve 1BAA reason for a fluctuating duty point could be avarying water level in the sump/tank, since herethe inlet pressure of the pump is changed by thedifferent level. On the discharge side, this changecan be due to incrustation of the pipeline or dueto the throttling of the valves or the load.A, B = duty pointsSpeed and duty pointH geoMax-LevelH geoMin-LevelFlow Q [m³/h]Practically speaking, the system curve onlychanges by increasing or decreasing the resistances(e.g. closing or opening the throttlingelement, change in the pipeline diameter whenmodifications are carried out, incrustation, etc.)when there are solid-free fluids of normal viscosityin the system.Delivery head H [m]Valve furtherthrottledB 3System curves H AB 2B 1Open gate valveQH curveB = duty pointFlow Q [m³/h]Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 7

PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 8FUNDAMENTALSA change in the duty point can generally onlybe achieved by changing the speed n or the impellerdiameter D of a pump in the case of radialimpellers.pValve authority∆p PQ 1 n 1=Q 2 n 2 H 2 n 2H 1 n 12= P 2 n 2P 1 n 12=Delivery head H [m]Delivery head H [m]Delivery head H [m]Change in flowChange in speedH 1n 1n 2H 2Q 1H 1B = duty pointn = speedQ 2Change in the impeller diameterø D 1ø D 2H 2Q 1Q 2Q 1 D 1 D 2 D 1Q 2 D 2 H 2 D 2H 1 D 12 D 2 D 1System curve H AB 1B 2B 3n 1n 2n 3D 1 D 2Q 2Q 1H 2H 1QH curvesFlow Q [m³/h]Flow Q [m 3 /h]Flow Q [m³/h]p 0Pump curve with valve authorityFor the working characteristics, it is importanthow high the pressure drop at the valve is whenthe valve is completely open with respect to thetotal pressure at the lines to be regulated. Thisratio is called the "valve authority P v ":∆p v100 ∆p v100P V = ==∆p ges ∆p v + ∆p rAbbreviationp 0∆p P∆p v∆p rp b∆p LV˙V˙100P VDescriptionMaximum pump pressurePressure loss in the pumpPressure drop at the valvePressure drop in the rest of the systemReference pressure of the systemPressure loss in the systemFlow∆p LFlow with valve completely openValve authorityPump curveNetwork curve0 0.2 0.4 0.6 0.8 1.0∆p v100∆p v0V˙/V˙100The last expression is especially practical froman instrumentation point of view because thevalve authority can be calculated from the pressuredrop at the open (∆p v100 ) and at the closedvalve (∆p vo ).p 0∆p v100 ∆p P100∆p L100∆p v8 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 9FUNDAMENTALSSuction behaviour of the centrifugal pumpGeneralThe cause of pump suction is the pressure appliedto the liquid level in the suction tank,so in the case of an open tank, this is the atmosphericair pressure. Its mean value at sea level isp b = 101320 N/m 2 (= 1.0132 bar) and is equivalentto the pressure of a water column 10.33 m high at4 °C. Thus, normal air pressure must allow thepump to be able to pump water from a depth ofabout 10 m. The actually reachable geodeticsuction head H S geo is considerably less, however.The reasons for this are:• Fluids evaporate when the temperature-dependentvapour pressure p D N/m 2 is reached.The pressure can then only drop to this value atthe highest point of the suctioned fluid column.• Pump head losses occur in the suction line as aresult of speed generation – v S 2 /2 g [m] –, aswell as due to fluid friction, direction changesand changes in cross-section H VS [m].A further pump head loss is caused by frictionand speed changes when the fluid enters theblade channels. To avoid vapour formation, thetotal head (static pump head plus the velocityhead v S 2 /2g) in the entry cross-section of thepump must therefore be greater than the vapourpressure head of the pumped fluid by a certainamount. This energy difference is referred toas NPSH [m], the abbreviation for "net positivesuction head", and is identical with the previouslycommon term "maintained pressure headH H ".When the pump is installed above the suctionwater level, and the shaft is horizontal and thesuction tank open, the head difference H S geomay not be greater thanp b P DH S geo = - - H VS - NPSH [m]g · ρ g · ρwith gravitational acceleration g in m/s 2 andthe density ρ in kg/m 3 . If the suction tank isclosed, then the absolute pump head in thetank (p I + p b )/g · ρ appears for p b /g · ρ, wherebyp I stands for the overpressure in the tank.With the pressure units in bar, the density ρin kg/dm 3 and g = 9.81 m/s 2 , the equation takeson the following generally valid form:10.2 · (p b + p l - P D )H S geo = - H VS - NPSH [m]ρIn the case of underpressure in the suction tank,p I has a negative sign.Required NPSH (NPSHR)The smallest value of the NPSH at which thepump can be continuously operated under thegiven working conditions (speed, flow, deliveryhead, pumped fluid) can be determined fromthe pump curves in the catalogues. The NPSHdefined this way is also called NPSHR (NPSHrequired). It is not a constant value, but stronglyincreases with increasing flow. If one comparescentrifugal pumps having different specificspeeds, one can see that the NPSH value growswith increasing specific speed. The suction thendecreases. Pumps which run very fast can thereforeoften only overcome low suction heads oreven only be operated at inlet head, even withcold water. Improvement is possible by selectinga lower operating speed, but this at the cost ofeconomic efficiency.Available NPSH (NPSHA)For an existing or planned system, the NPSHAavailable at the entry cross-section of the pumpcan be determined by solving the equation forNPSH:10.2 · (p b + p l - P D )NPSHA = - H VS - H S geo [m]ρIf the fluid level is above the pump, instead ofH s geo the geodetic inlet head H z geo is pluggedin and the equation becomes:10.2 · (p b + p l - P D )NPSHA = - H VS + H S geo [m]ρ• When planning a pump system, it is recommendedthat a pump be selected which hasan NPSHR at least 0.5 m lower than the availableNPSHA.• For a pump in operation, by measuring the pressurep1 at the suction flange of the pump, theNPSHA can be calculated from the equation10.2 · (p b + p l - P D ) v 2 1NPSHA = + - H S geo [m]ρ2 · gwith the previously given units for the pressureand density. If this is an underpressure, p 1 isgiven a negative sign. The quantity v 1 is theaverage flowrate in the entry cross-section A 1of the pump, v 1 = Q/A 1 with Q in m 3 /s and A 1in m 2 .Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 9

PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 10FUNDAMENTALSInfluence of air pressureThe magnitude of the atmospheric air pressurehas a considerable effect on the suction. Apartfrom weather-related fluctuations of ± 5% ofthe customary mean value, the air pressure decreaseswith increasing altitude:Altitude above sea level 0 500 1000 2000 3000 mAverage air pressure p b 1.013 0.955 0.899 0.794 0.700 barInfluence of fluid temperatureWhen hot water is pumped, the vapour pressurehead plays a major role. If a fluid is boiling,pI + pb = pD and Hs geo becomes negative.An inlet head Hz geo is therefore required.Furthermore, the equation can be simplified toNPSHA = H Z geo -H VS [m]Also for temperatures which lie under the boilingpoint, suction is reduced so that even then aninlet head might be necessary.Influence of the fluid temperature on the inlet head43mH S geo H Z geo210-1-2-3-4-52030 40-650 60 70 80 90 100T W °CIt is assumed that a pump can overcome a geodeticsuction head of H S geo = 6 m at a watertemperature of 20°C. With increasing watertemperature, and therefore also increasingvapour pressure, H S geo decreases and at a watertemperature of t W ≈ 87 °C turns into an inlethead, which has the constant minimum valueH Z geo = 4 m once the boiling state has beenreached.10 Subject to change without prior notice 08/2006 WILO AG

PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 11FUNDAMENTALSPump efficiencyThe ratio of the delivered power – hydraulicpump capacity (flow x delivery head) – to theabsorbed power (drive power) is given by thepump efficiency. The efficiency changes alongthe pump curve.In building engineering, the pump efficiency isonly given indirect consideration when assessingthe pump. For this reason, this is often omittedfrom documentation. The power consumptionof the pump is the crucial factor.Delivery head H [m]Pump curve and efficiency curveηHOnly in larger aggregates, for example in processengineering or in large plant construction, wherethere is a differentiated consideration of thepump operation, these efficiency specificationsare mandatory.Flow Q [m³/h]Pump curve and efficiencycurve in the Q vs.H diagramThe pump efficiency is defined:η P =In the case of pumping in the customary temperaturerange for building engineering, thefollowing modified equation can also be used.η P =Q · H · ρ · gPQ · H367 · PSince the efficiency and power consumptionhave a direct relationship, a duty point withmaximum efficiency should be selected withregard to the operating costs.In general, the range of the best pump efficiencyis in the centre third of the pump curve. Pumpdimensioning in the first or last third of the pumpcurve always means operation in the worsepump efficiency range and should be avoided.For pumps where the drive motor is designedfor the entire curve, another thing that must beconsidered is that electromotors have their bestefficiencies only under full load, or at the maximumpermitted flow. This means, taking bothfactors into consideration, that the optimumduty point is shifted to the right of centre ofthe curve.Abbreviation DescriptionUnitη PPump efficiencyQ flow m 3 /sH delivery head mρ mass density of the fluid g [m/s 2 ] kg/m 3P power of the motor (shaft power) Wg local gravitational acceleration m/s 2367 3600 sec divided by 9.8665 = local gravitational accelerationWith pumps of the glandless series where thepump and motor form one encapsulated unit,instead of the pump efficiency η P customaryfor glanded pumps, the total efficiency η PGesis specified. They are coupled via the motorefficiency η M .The cause for this differentiated form of representationis the different construction form ofboth pump types.Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 08/2006 11

PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 12FUNDAMENTALSPower requirements of the pumpIn the case of glanded pumps, a multitude ofdrive motors (standard motors, special motors)are used which have very different efficiencies,making it necessary to determine the individualoverall efficiency.In the case of glandless pumps, special motorsare fundamentally used which are exactly tunedto the pump. It is not possible to separate theunits motor and pump. Thus, the overall efficiencyfor every pump is exactly fixed.The efficiency of motors for glandless pumpscan't be directly compared with the efficienciesof motors for glanded pumps. The completelydifferent designs and applications forbid comparison.Encapsulated motors are speciallydeveloped for use in building engineering.The water level in the rotor compartment andthe metallic separation (can) between the rotorand winding result in an efficiency which is lowerby a factor of 2 to 4 than in standard motors.Efficiencies with standard glandless pumps (approximate values)Pumps withmotor power P 2 η M η Pump * η Gesamt **up to 100 W approx. 15 – approx. 40 – approx. 5 –approx. 45 % approx. 65 % approx. 25 %100 to 500 W approx. 45 – approx. 40 – approx. 20 –approx. 65 % approx. 70 % approx. 40 %500 to 2500 W approx. 60 – approx. 30 – approx. 30 –approx. 70 % approx. 75 % approx. 50 %To exactly design the pump drive and to calculatethe operating costs/efficiency, knowledgeof the required power at the respective pumpduty point is necessary. The required power orpower consumption of the pump is thereforealso shown in a diagram like the hydraulic flowrate of the pump.The dependency of the drive power of thepump on flow is shown. At max. flow, the max.required power of the pump is also reached.The drive motor of the pump is designed forthis point when the pump is operated over theentire curve.Glandless pumps are always furnished with motorswhich allow operation over the entire curve.This way, the number of types is reduced, makingreplacement parts easier to keep in stock.If the calculated duty point for a pump (glandeddesign) lies in the front range of the curve, forexample, the drive motor can be selected smalleraccording to the associated power requirement.In this case, however, there is the danger of motoroverload when the actual duty point lies ata greater flow than calculated (system curve isflatter).Efficiencies for glanded pumps (approximate values)Pumps withmotor power P 2 η M η Pump * η Gesamt **up to 1.5 kW approx. 75 % approx. 40 – approx. 30 –approx. 85 % approx. 65 %1.5 to 7.5 kW approx. 85 % approx. 40 – approx. 35 –approx. 85 % approx. 75 %7.5 to 45.0 kW approx. 90 % approx. 40 – approx. 40 –approx. 85 % approx. 80 %* Variations depend on design,nominal diameter, etc.The smaller value generallyapplies for pumps with extremelylow volume flow andrelatively high delivery head.** Limit values of η Ges orη Pump don't have to correspond.Since, however, the encapsulated motor alsogives off approx. 85 % of the motor heat to thefluid, the percentage heat loss is very low.The table above shows a general overview ofpump efficiencies. It can be seen that the efficiencyimproves with increasing pump capacity,since losses within the pump remain nearly constant,thus having a smaller effect compared tothe increasing overall pump capacity.12 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 13FUNDAMENTALSDelivery head H [m]Hydraulic flow rate of the pumpPumpBFlow Q [m³/h]Flowrate vThe electric power consumption P 1 is givenwhen the pump and drive motor form an encapsulatedunit, like with the so-called glandlesspumps. Here, it's even customary to put bothvalues P 1 and P 2 on the name plate.For aggregates where the pump and motor arecoupled via a coupling or rigid shaft connection,like with the glanded pumps, the required shaftpower P 2 is given. This is required for thesepump designs since the wide variety of motordesigns – starting with the IEC standard motorto the special motor – with their various powerconsumptions and efficiencies are installed onthe pump.Power requirement P [w]System curveBFlow Q [m³/h]Since in practice a shift in the duty point canalways be expected, the power of the drivemotor of a glanded pump must be set by approx.5 to 20% higher than the assumed requirementwould be.To calculate the operating costs of a pump, itmust be fundamentally distinguished betweenthe power requirement of the pump P 2 , oftenequated with the installed motor power, andthe power consumption of the drive motor P 1 .The latter is the basis of the operating costcalculation. If only the power requirement P 2 isgiven, this can also be used, but by simultaneouslytaking the motor efficiency into accountaccording to the following equation.The power consumptions of the pumps given inthe documentation of the pump manufactureralways refer to the water as the fluid in the areaof building engineering with:Specific density ρ = 1000 kg/m 3Kinematic viscosity ν = 1 mm 2 /sWhen there is a deviation in the specific density,the power consumption changes proportionallyto the same degree.Lower spec. density ^- Lower power consumptionP 1Higher spec. density ^- Higher power consumptionP 1This practically means that pumps which areoperated at high water temperatures, and thuslower spec. density of the fluid, usually requirelower motor power. For the temperatures andpump capacities which can be found in buildingengineering, this correction isn't carried out.Thus, on the drive side there is a certain motorreserve.When there is a deviation in the kinematic viscosity(by admixing to the fluid, only viscosityincrease relevant), there is also a change in thepower consumption.P 2P 1 =η MAbbreviationP 1P 2η MDescriptionPower consumption of the drivemotorPower requirement at the pumpshaftMotor efficiencyHigher viscosity ^- Higher power consumptionThe change is not proportional and must bespecially calculated.Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 13

PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 14FUNDAMENTALSPressure behaviourPressure diagramp∆p L5∆p v ∆p L6 p 0 -∆p pEV∆p L4L∆p p∆p L3∆p L4∆p L5∆p vp 0p b∆p L6∆p L3∆p L1∆p L1∆p L2∆p L2Pressure curve in pipelines and fittingsPressure losses are reductions in the pressurebetween the component inlet and outlet.Among these components are pipelines, aggregatesand fittings. The losses occur due to turbulenceand friction. Every pipeline and fittinghas its own specific loss value, depending onthe material and surface roughness. The specificationscan be obtained from the manufacturer.An overview of the standard losses used by Wilocan be found in the appendix.AbbreviationEVp 0∆p P∆p v∆p rp b∆p LPressure surgeDescriptionGeneratorLoadMaximum pump pressurePressure loss in the pumpPressure drop at the valvePressure drop in the restof the systemReference pressure of the systemPressure loss in the systemIf a pipeline with flowing fluid is suddenly closedat one spot, the fluid mass inside it can only cometo rest with a time delay due to its inertia. Dueto this "negative" acceleration of the fluid mass,the forces applied to the pipe wall and shut-offdevice increase (F = m · a). Such types of pressuresurges must be observed in the dimensioningof pipeline systems (telescope lines, coolingwater circuits, etc.) as the maximum load. Airchambers are installed for damping the pressuresurge.Abbreviation DescriptionUnita Acceleration m/s 2Speed(Speed of sound for water ~ 1 400 m/s)m/sρ Density kg/m 3m Mass kgF Force NV˙ Volume flow m 3 /hEspecially endangered here are installationswhere lines are not laid continuously falling orrising. Since the water columns can break off atthe high points (vacuum formation) or increasedpressure is created when water columns meet,pipes could burst.The pressure increase when there is a suddenclosing of a throughflow fitting is simplified asfollows:∆p = ρ · V˙ · 14 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 15FUNDAMENTALSPumping of viscous mediaThe representation of the pump capacity data inthe Q vs. H diagram also usually refers to wateras the fluid, as in the calculation of the systemcurve, with a kinematic viscosity of ν = 1 mm 2 /s.The pump data changes for fluids of other viscositiesand densities. The data correction whichshould be done even for hot water pumping tobe correct can be neglected in building engineering.There only has to be a check for seriouschanges (more than 10% volume percentage)in the water when additives are used, such asglycol, etc. Hereby, it is to be observed that theplanning of pump systems, and thus the determinationof the pump data Q, H, P, is divided upinto two sections for pumping fluids of higherviscosity.• It may only be used when there is a completelyadequate maintained system pressure value(NPSHA) available.The values to be specified for determination are:1. Operating temperature t [°C] of the fluid atthe pump.2. Density ρ [kg/m 3 ] of the fluid at lowest specifiedoperating temperature.3. Kinematic viscosity ν [cSt or mm 2 /s] of thefluid at the lowest specified operating temperature.4.Required volume flow of the fluid Q vis [m 2 /h].5. Required delivery head of the fluid H vis [m].Sample curve for potential changes in a circulating pumpChange in the system curveA correction in the system curve / characteristicsof existing systems calculated for water pumpingfor operation with fluids of other viscositiesand densities must be done taking the changingflow characteristics into account. These correctionfactors can not be specified by the pumpmanufacturer.The new system curve can be determined withthe help of the relevant flow-related professionalliterature / information from the fittingsmanufacturers.Delivery head H [m]8,07,06,05,04,03,02,01,00,0 1,0 2,0 3,0 4,0 5,0 6,0 7,0 8,0Flow Q [m³/h]Change in the flow rate dueto higher fluid viscosityChange in the pump characteristicsSimilar to how it is in the system, influences onthe frictional moments and inner flow conditionsarise in the pump as well due to the changedfluid properties, which, added up, can result ina deviating pump curve. The electric power consumptionof the pump unit is influenced. Sinceindividual measurements of all pumps aren'tfeasible for many possible operating media dueto cost reasons, various conversion methodshave been developed (Hydraulic Institute, pumpmanufacturer, etc.). The methods have limitedprecision and are subject to certain restrictions.NotesThe described method is sufficiently accuratefor determining the flow rate for Wilo screwedconnectionand flange-end pumps when thefollowing basic conditions are complied with:η ges [-]P 1 [W]0.400.350.300.250.200.150.100.050.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0Flow Q [m³/h]300250200150Change in the efficiency dueto higher fluid viscosity• It may only be used for homogenous Newtonfluids. In the case of muddy, gelatine-likefibre-containing and other inhomogeneousfluids, there are strongly scattered results.100500.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0Flow Q [m³/h]Change in the motor powerdue to higher fluid viscosityWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 15

PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 16FUNDAMENTALSInstructions for preliminary pump selectionwith the specifications of the delivery head,rate of flow and the viscosity conditions.When the desired flowrate and delivery head forthe fluid, as well as the viscosity and relativedensity are given at a certain pump temperature,the following equations are used to find out anapproximately equivalent power with water andto estimate the drive power of the pump for viscousfluids. Please observe that the results areless exact when you begin with the viscous conditionsinstead of with a known water performancefor determining the required water performance,except when this is involves repetitions.Step 1Calculate parameter B with the specified metricunits Q vis in m 3 /h, H vis in m and V vis in cSt withthe help of equation:B = 280 ·(V vis ) 0.50(Q vis ) 0.25 · (H vis ) 0.125If 1.0

PLH_KKK_U2_31.QXP 25.05.2007 11:01 Uhr Seite 17FUNDAMENTALSRequired NPSHR visThe viscosity of the fluid has a two-fold influenceon the NPSHR value. With increasing viscosity,the friction increases, which in turn leadsto an increase in the NPSHR value. At the sametime, a higher viscosity leads to reduced diffusionof air and vapour particles in the fluid.Thus, bubble formation is slowed down andthere is also a thermodynamic effect, whichleads to a slight reduction in the NPSHR value.The effect of viscosity on the NPSHR value isbasically a function of the Reynolds number.However, this effect cannot be expressed usinga single relationship for all the different pumpdesigns and models. As a general rule: Pumpswith larger dimensions and consistent and wideimpeller inlet openings are less susceptible whenthere are changes in the viscosity of the fluid.Conversion to new delivery data by means ofEDP supportThe Wilo Select program is very recommendablefor converting from water to other viscosities.A relatively exact calculation is made with thestored data. However, it must be observed thatthe known calculation method according toISO/TR 17766 and the Hydraulic Institute etc. involvea tolerance. Exact specifications can onlybe determined by individually testing the pumpswith the actual fluid at concrete operating conditions.To do this, a special job order must begiven to the pump manufacturer.Gas dissolved in the fluid and gas entrained bythe fluid in the form of dispersed bubbles impairthe NPSHR value in a manner different from thatof large gas bubbles. When the flowrate at theinlet opening of the pump is high enough, smallamounts of the entrained gas are not separatedand usually have no or only a small effect on theNPSHR value. If, however, there are larger gasbuild-ups, this has a major effect on the pumpsuction. Then the NPSHR curves of the totaldelivery head change their shape from a welldefined"knee" to a step-like incline of thedelivery head. This increases the point of thedelivery head loss of 3 %, or in other words:The NPSHR value increases.The equations here are used for calculating thecorrection factor for adjusting the NPSHR valuefor the pump water performance, based on a standarddelivery head drop of 3 % on the NPSHR visvalue with the corresponding viscous liquid:1NPSHR BEP-WC NPSH = 1 + A · − 1 · 274 000 ·{ (C (Q BEP-W ) 0.667 · N 1.33H) ] }A = 0.5 for lateral suction portA = 0.1 for axial inlet[Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 17

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PLH_KKK_U2_31.QXP 25.05.2007 11:02 Uhr Seite 19Noises – Airborne sound –Structure-borne soundTo prevent or reduce potential bothersome noise, the pump operationin residential building systems requires special attention in theselection of suitable pumps / in the planning and execution of theinstallation.Especially in residential buildings, the problemof noise reduction plays a major role in comfortdemands, especially during the night hours.For the permitted noise level value in commonareas, the following regulations are to be observed:• DIN 4109, Noise protection in building construction• VDI 2062, Vibration insulation• VDI 2715, Noise reduction in warm and hotwaterheater systems• VDI 3733, Noises in pipelines• VDI 3743, Emission characteristics of pumpsPumps as noise generatorsIt is unavoidable that pumps make noise. Wilo asa manufacturer is doing its best to deliver pumpswhich are as quiet as possible.In residential building systems, centrifugal pumpsare mostly used. The noise they make can basicallybe divided into the following main groups:Flow noiseThe flow noises have various causes. A noisehaving a large frequency range, which soundslike hissing, is caused by the turbulence andfriction of the water particles on the surface ofthe parts being flowed through.Frictional processes also cause an irregular speeddistribution in the boundary layer, which can resultin alternating movements of the water flowoff the pipe wall causing subsequent turbulenceformation. This periodical vortex shedding createsa more or less pronounced single sound.Furthermore, the speed of the flow fluctuatesafter it leaves the impeller. These irregularitieslead to noise being generated in the connectedpipes. Since the frequency of these noises dependon the pump rotation speed and the numberof blades, one refers to the blade frequencyof the pump.Cavitation noiseThe cavitation noises in a pump are caused bythe formation and the sudden collapse of vapourbubbles in flowing water.Noise due to mass forcesVibrations, excited by mass forces, which lead tonoises, are caused by imbalances in rotating parts(impeller, shaft, coupling, etc.). Despite the mostmodern balancing technology, the imbalancecomes from alternating bearing forces, productionimprecisions or material wear or accretion.The frequency of imbalance vibrations is alwaysthe same as the rotational frequency of the rotatingparts.Noise due to friction on bearings and sealedplaces.Vibrations caused by friction on bearings andseals, which lead to noise, are not that importantwhen the pumps are working properly.Electromotor noisePumps are usually driven by electromotors in residentialbuilding systems. The noise which comesfrom the electromotor only belongs to the pumpnoise when the pump and electromotor are designedin a block. In the electromotor, sounds arecaused by electromagnetic processes at doublethe mains frequency (100 Hz) and, depending onthe number of poles, mostly between 600 and1200 Hz. Noise with a high frequency range isproduced by the fan of the motor, similar to thepump, which is superimposed with the blade frequencyof the fan as a single sound.Other noisesFurthermore, rolling noises from the ball bearingsas well as whistling noises on the dry-runningpacking glands and mechanical seals canoccur.Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 19

PLH_KKK_U2_31.QXP 25.05.2007 11:02 Uhr Seite 20NOISES – AIRBORNE SOUND – STRUCTURE-BORNE SOUNDAirborne noiseThe airborne noise which comes directly fromthe pump can be heard in the boiler room. In theneighbouring lounge areas, however, it can hardlybe heard when ceilings and walls of the boilerroom are built according to DIN 4109. At the usualsound-damping dimension, the figure to theright can be referred to for assessing permittedairborne noise levels.If the octave spectrum of the circulating pumpdoesn't go over the limit at any frequency, thenthe airborne noise of the transmitted noise alsoremains under 30 dB in the lounge areas.dBLimit for the octave spectrum9080706050Limit curve40125 250 500 1000 2000 4000HzStructure-borne sound and waterborne soundCompletely different conditions may arisethrough the transmission of structure-borneand waterborne sound. If pump noises can benoticed outside of the installation room, it isvery probable that this is the transmission ofstructure- and/or waterborne sound via thebuilding structure along the pipeline. Along thepipeline, waterborne noise spreads out via thewater column and structure-borne sound via thepipe wall in the pipework. Practice shows thatthey usually occur together.Structure- and waterborne sound are not directlydiscernible by the human ear. Only when waterbornenoise makes the pipe wall vibrate, causingthe surrounding air to vibrate, there is an audibleairborne noise.This property of not being directly discernible,which is to be considered favourable, is far outweighedby the unfavourable property of thenearly lossless conduction via the pipeline system.Pipelines are well suited for transmittingvibrations due to their elasticity, and thereforemake up an ideal transmission system for noises.In the case of resonance, the noise is not onlyrelayed, but even amplified. Like all elastic bodies,even pipelines have so-called resonance frequencies,which depend on various factors.If this pipeline resonance frequency shouldhappen to be identical with the excitement frequencycoming from the circulating pump, it beginsto resonate. Here, a very low excitementenergy is enough to make the pipeline stronglyvibrate. This also means that there is strongnoise development. Vibration tests have shownthat resonance frequencies can occur in highnumbers in systems designed in the frequencyrange of interest (between 50 and 1000 Hz).Thus, the possibility of resonance occurring isalways there. It is not possible to do a precalculationof pipeline resonance frequencies due tothe complex relationships.In the case of disturbances in the residentialarea, which are caused by noises in residentialbuilding systems, the main difficulty is thetransmission of structure-borne and waterbornenoise via the pipe system. Therefore, measureshave to be taken to prevent the unhinderedtransmission of structure-borne and waterbornenoise. The VDI directive 2715 provides a fewvaluable tips here.Structure-borne noise via the building structureIf a pump is directly connected with the buildingstructure, this can be made to vibrate. Furthermore,vibrations can be introduced to walls andceilings via pipe fixtures.20 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_U2_31.QXP 25.05.2007 11:02 Uhr Seite 21NOISES – AIRBORNE SOUND – STRUCTURE-BORNE SOUNDMeasures against noisesA major precondition for the effective and sensibleprotection against noise from pumps whichare installed in residential building systems is thecooperation of all parties involved in creatingthe building. Architects and planners are giventhe task to select floor plans so that favourableacoustic conditions can be created. Thus, roomsor components with noise-generating apparatuses,such as home technical systems, shouldbe placed as far as possible from the living areas.The operating behaviour of the pump is influencedby the connected pipelines and other systemparts; this also has an effect on the noisetransmission. The relationships are so manifold,so that no simple rules can be established,where one can say with certainty that noisescan be completely ruled out.The following items should always be observedwhen selecting a pump:• Pumps should be operated at the point of thebest efficiency, if possible.• This demand can be best met by not makingany exaggerated safety allowances in the pressureloss calculation.Measures for avoiding flow noises due topipeline conductionIn the development of flow noises in a systemmade up of a pump and pipeline, the pipelineconduction and rate of flow play significantroles.FlowrateIt is to be observed that the nominal pipelinediameter is usually equal to or greater than thenominal connection width of the pump.Required cross-sectional modifications are to bedesigned favourable to flow and centrically.The table below contains nominal width-relatedrecommendations for flow rates in the connectionof the pump, which should not be exceededin order to avoid noise.The pipeline on the pump inlet side should runstraight over a length of at least 5 · d in order toprovide favourable hydraulic conditions at theimpeller inlet.Aspects for determining and selecting pumpsNominal connection widths DNFlowrate vPumps should be operated at the point of optimumefficiency since then the optimum is notonly reached in max. economic efficiency, butalso in noise behaviour. Then, it is often possibleto go without additional noise-reducing measures.Often, in the designing of pumps for homeautomation systems, the safety allowances aremade much too high for the system resistance.This leads to an unnecessarily large pump beingselected, which is then not operated at the pointof optimum efficiency. Based on experience,a large percentage of noise complaints are aresult of this error. In selecting a suitable pump,it is important to know that pumps with lowspeeds generally demonstrate more favourablenoise behaviour.Ø mmm/sIn building installationsUp to 1 1 /4 or DN 32 up to 1.2DN 40 and DN 50 up to 1.5DN 65 and DN 80 up to 1.8DN 100 and greater up to 2.0Long-distance lines 2.5 to max. 3.5r 2,5 · (d · 2s)5d minrdsWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 21

PLH_KKK_U2_31.QXP 25.05.2007 11:02 Uhr Seite 22NOISES – AIRBORNE SOUND – STRUCTURE-BORNE SOUNDPipe support,Avoid pipeline forceson the inlet connectionLarge curvature radiusWhen the pipe diameter is reduced, suddencross-section changes are to be avoided.This is possible using conical adapters. If theformation of air pockets can be expected, eccentricadapters are preferable.Eccentric,conicaladapterMeasures against waterborne and structurebornesound propagation via pipelinesIntroducing waterborne and structure-bornenoise in pipelines can be prevented by specialdamping measures on the pump to the pipelines.A remarkable noise-reflecting effect from pipelinedirection changes is not expected with thewavelengths of the water-borne sound in homesystems and the dimensions of the pipelines.When sound-absorbing measures are taken, it isto be made sure that the operating safety of thepump isn't impaired, i.e. functionally reliabledamping elements must be selected. The followingexpansion joints come into question asabsorbing elements:5d min5d minFittings should not be installed in the pipelinedirectly after the pump connection, especiallynot on the entry side of the pump. Here, a minimumdistance of 5 · d also has a favourable effecton noise creation.Gate valve5d min• Expansion joints with length limitation withoutelastic elements (lateral expansion joints)• Expansion joints with length limitation withelastic elements as well as rubber metalflanges• Expansion joints without length limitationsFor expansion joints with length limitation withoutelastic elements, no additional pipelineforces act on the pump connection. But on theother hand, these expansion joints have only aslight absorbing effect. Expansion joints withoutlength limitations have the greatest absorbingeffect. With these, however, the largest additionalpipeline forces act at the same time. Thepipeline forces can theoretically reach 16 000 Nfor a pump with a nominal diameter of 100 andnominal pressure of 10. Practically speaking,however, due to the limited elasticity of the expansionjoints, only pipeline forces up to halfthis value can act. No generally valid statementscan be made at this time with regard to whatconnection forces are permissible.Pipe support22 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_U2_31.QXP 25.05.2007 11:02 Uhr Seite 23NOISES – AIRBORNE SOUND – STRUCTURE-BORNE SOUNDThe expansion joint with elastic length limitationis the "reasonable" compromise between noiseabsorption and connection forces in many applications.When absorbing elements are used,their limited service life and sensitivity to hotwater are to be observed.Expansion jointsExpansion joint without lengthlimitationLength limitersExpansion joint with lengthlimitation without elastic elements(lateral expansion joint)Elastic elementsExpansion joint with lengthlimitation with elasticelementsThe effectiveness of the absorbing measurescan be seen in the figures on page 24, whichshow oscillograms of structure-borne noisemeasurements on a pipeline made to vibrate bya heating circulation pump. Depicted are threedifferent cases of structure-borne noise, whichinclude the unfiltered measuring signal and thefiltered-out low- and high-frequency portions,i.e. their blade frequency of 150 Hz (4-pole electromotor,impeller with six blades) or the electromagneticfrequency of 600 Hz.In the first case, the state is shown with thepipeline connected with the pump. In the secondcase, the state is shown after the installationof rubber/metal pipe connectors on the inletand outlet sides. As can be seen, thehigh-frequency portions are considerably reduced.By installing rubber expansion joints(third case), both the high-frequency and lowfrequencyportions are greatly reduced.Whether the absorbing measures in cases 2 and3 are appropriate for the individual case dependson the frequency of the dominant system noise.The absorbing measures described using the exampleof pumps having in-line construction canbe also applied sensibly for pumps set up on thefloor.Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 23

PLH_KKK_U2_31.QXP 25.05.2007 11:02 Uhr Seite 24NOISES – AIRBORNE SOUND – STRUCTURE-BORNE SOUNDExpansion jointsCase 1Rigid installation,no absorbing effectStructure-borne noisemeasuring pointCase 2Only the high-frequencynoise (600 Hz) is reducedwith rubber/metal pipeconnectors.Structure-borne noisemeasuring pointCase 3The high-frequency noise(600 Hz) as well as the lowfrequencynoise (150 Hz) isreduced by rubber expansionjoints.Structure-borne noisemeasuring pointSupport fixture withrubber/metal elementKey:top:centre:bottom:Overall measuring signallow-frequency noise (150 Hz)high-frequency noise (600 Hz)24 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_U2_31.QXP 25.05.2007 11:02 Uhr Seite 25NOISES – AIRBORNE SOUND – STRUCTURE-BORNE SOUNDMeasures against structure-borne noise transmissionto the structureWhen pumps are set up on the floor, in order tosuppress structure-borne noise transmission, itis also often required to support them with elasticelements between the baseplate and floor inaddition to vibration insulation from the pipelines.This way, vibration transmission to thestructure is prevented. If pumps are set up onfloor slabs, the elastic support is absolutely recommendable.Special care must be taken withpumps having varying speed.The elastic elements are to be selected accordingto the lowest excitement frequency (this isusually the speed). The spring stiffness mustdecrease with decreasing speed. In general,natural cork plates can be used for a speed of3000 rpm and more, for a speed between 1000and 3000 rpm rubber/metal elements can beused, and for a speed under 1000 rpm, spiralsprings. When pumps are set up on the basementfloor, often plates made of natural cork,mineral wool or rubber can be used as an elasticbase.In the figure it is shown how the vibration dampingof a pump unit is to be designed. Theabsorption effect depends on the resonancefrequency of the elastically supported pumpunit. Put simply, the resonance frequency isdetermined from the weight of the pump unitand the spring stiffness of the elastic elements.The resonance frequency of the system f O can beseen in the diagram below.Damper compression under static load ∆l [mm]200180160140120100806040200f 0 [Hz]1 2 3 4 5 6 7 8 9 10Resonance frequency f 0 [Hz]In order to achieve good absorption, the resonancefrequency of the system f 0 must lie considerablybelow the excitement frequency fromthe pump f err .In the case of pumps which don't have balancedmass forces, the oscillation amplitude can bereduced by increasing the foundation mass.16∆l mmPipeline fixed pointPipeline fixedpointConcrete foundation as stabilising massSpring elements with dowels fastened or glued onWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 25

PLH_KKK_U2_31.QXP 25.05.2007 11:02 Uhr Seite 26NOISES – AIRBORNE SOUND – STRUCTURE-BORNE SOUNDPipe suspensionWhen designing the elastic support, make surethat no acoustical bridges are created. Therefore,bypassing the elastic support with plasteror tile is to be avoided. Every impairment in thefreedom of movement of the pump unit ruinsthe absorption effect or at least reduces it considerably.S = vibration dampingWhen laying the pipe it is to be made sure thatthere is never a fixed, rigid connection with thebuilding structure. The pipe fixtures should beinsulated from structure-borne noise. This is especiallyto be made sure when installing pipes inthe wall. Suitable prefabricated fixing elementsare available in special stores.Special attention is to be given to pipe feedthroughsthrough walls and ceilings. There arealso prefabricated collars available in specialstores which meet all requirements for good insulationagainst structure-borne noise.Structure-borne noise-absorbing pipefeed-throughThe pipe insulation against structure-bornenoise with respect to the building structure mustbe executed with great care since every mistake,even at only one place, can ruin the entire insulationeffort.26 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_U2_31.QXP 25.05.2007 11:02 Uhr Seite 27NOISES – AIRBORNE SOUND – STRUCTURE-BORNE SOUNDPressure on the suction port of the pumpSufficient pressure on the suction port of thepump should prevent cavitation on the impeller.Cavitation is the formation and sudden collapseof vapour bubbles. The vapour bubbles form inplaces where the pressure of the flowing fluiddrops until the value of the vapour pressurereaches the value which the fluid has at theprevailing temperature. The vapour bubbles arecarried off with the flow and collapse when thepressure increases above the vapour pressurefurther along the flow path.Cavitation must be avoided since the flow rate,noise behaviour and smooth pump operation arenegatively influenced and can even lead to materialdamage.To keep these faults from occurring during operation,the "minimum required net head" at theinlet of the pump is required (see pump catalogue).This NPSH value depends on the flow inevery pump. Each pump size has its own NPSHcurve at a given speed, which was determinedby the pump manufacturer by means of measurement.The planner must provide an "NPSHsystem" in the system, which is equal to orgreater than the NPSH value of the pump at themost unfavourable duty point. The figure showsthe value of the overpressure compared to theatmospheric pressure which must at least beavailable at the pump suction side, shown vs.the NPSH value of the pump.The figure indicates the minimum required overpressurewith respect to the atmospheric pressurewhich must be available at the suction portof the pump. The curves apply for a maximumflow rate of 2 m/s and for an installation altitudeof 100 m above sea level.For installation altitudes higher than 100 m, theread-off value P E , which depends on the NPSHvalue of the pump and the water temperature,is to be corrected. The following applies:P* P E + X · 0.0001=The value X is the real altitude (in m) of the installationsite, measured above sea level.Required inlet pressure depending on temperatureP E [bar]Req. overpressure against the atmospheric pressureon the suction side of the pump54321Water temperature °C14013012011010000.5 1 2 3 4 5 10 20NPSH in accordance with pump curve [m]Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 27

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PLH_KKK_U2_31.QXP 25.05.2007 11:02 Uhr Seite 29Pump intakePump sumpA pump sump is required when there is irregularintake and pumping off of the delivered fluid.The size of the sump depends on the pump flowand the permissible switching frequency of theelectromotor. The useful volume of the pumpsump is calculated with :Q m =V N = Q zu ·Q e + Q a2Q m - Q zuQm · ZAbbreviation DescriptionZmaximum permissible number of switches per hourQ zu Delivery in m 3 /hQ e Flow at the switching-on point in m 3 /hQ a Flow at the switching-off point in m 3 /hV N Useful volume of the pump sump in m 3Any backflow volume is to be added to this,if necessary.If contaminated fluids are used, it must beavoided that solid matter gets deposited onthe floor. This can be avoided with inclinedwalls of at least 45°, or better 60°.Suction tankd E0.5 d ESuction pipeTo avoid turbulence and the formation of shearingforces due to irregular intake, an impact surfacein the pump sump is recommendable.45 to 60°Pump sump with impact surfaceImpact surfaceWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 29

PLH_KKK_U2_31.QXP 25.05.2007 11:02 Uhr Seite 30PUMP INTAKESuction lines and suction tanksThe minimum distances of the suction line from walls and tank floor:DN 25 32 40 50 65 80 100 150 200B in mm 40 40 65 65 80 80 100 100 150Suction and minimum distancesd E>_ 6 d ESuction tank with impact surfaceSuction lineFeed lineincorrect>_ d EBSImpactsurfaceSuction tank>_ 5,5 d EIn order to prevent air or turbulence from enteringthe suction line, the distance between thesuction and inlet lines must be sufficiently large.Also, impact surfaces should be included. The inletpipe must always enter under the fluid level.Also, it must be made sure that there is a sufficientlyhigh fluid coverage over the suctionopening. When there is insufficient coverage,turbulence caused by air suction can result.Beginning with a funnel-shaped depression inthe fluid level, an air hose forms from the surfaceto the suction line. This results in turbulentflow and a drop in pump performance.For an exact calculation, the following formula isto be used according to the Hydraulic Institute:S min d E + 2.3 · v S ·=Abbreviation DescriptionS min Minimum submergence in mv SRate of flow = Q/900 d 2 E in m/s,recommended 1 to 2 m/sbut not > 3 m/sQ Flow in m 3 /hg Gravitational acceleration 9.81 m/s 2d Ed EgInlet diameter of the suction pipeor the inlet nozzle in md E0,5 d Ev ESB>_ d EBSv EIf the minimum submergence can't be provided,floats or swirl-preventing conductor surfacesare to be provided to prevent turbulence causedby air suction.Suction tank and floatThe minimum submergence S min for the recommended flow rates of0.5 to 3 m/s are:DN 25 32 40 50 65 80 100 150 200S min m 0.25 0.35 0.65 0.65 0.70 0.75 0.80 0.90 1.25FloatSuction pipe30 Subject to change without prior notice 08/2006 WILO AG

PLH_KKK_U2_31.QXP 25.05.2007 11:02 Uhr Seite 31PUMP INTAKESuctioningThe standard circulation pumps are not selfpriming.This means that the suction line andthe pump housing on the suction side have to bevented so that the pump can work. If the pumpimpeller is not under the fluid level, the pumpand suction line must be filled with fluid. Thistedious procedure can be avoided when the inletof the suction pipe is equipped with a foot valve(non-return valve). Venting is only required atthe initial commissioning or when a fitting isleaky.Foot valveSuction operationDue to losses in the connection lines, pump andfittings, a maximum of 7 to 8 m suction head canbe achieved in practice. The head difference ismeasured from the surface of the water level tothe pump suction port.Suction lines are to be installed which have atleast the nominal diameter of the pump port,but if possible, should be one nominal diameterlarger. Reductions are to be avoided. Especiallyfine filters must be kept away from the suctionside. The suction line is to be installed so that ithas a continuous incline to the pump and a footvalve (floating discharge) is to be installed whichprevents the line from running empty. The lineshould be kept as short as possible. In long suctionlines, increased friction resistances arisewhich strongly impair the suction head.Air pocket formation caused by leaks are to beavoided under all circumstances (pump damage,operating faults).When hose lines are installed, suction- andpressure-proof spiral hoses should be used.Suction line installationcorrectincorrectWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 08/2006 31

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PLH_KKK_32_85.QXP 25.05.2007 10:10 Uhr Seite 33Pump performance controlThe volume flow conveyed through a circulatingpump is dependent on the thermal output/coolingoutput requirement of the system beingsupplied. This requirement fluctuates dependingon the following factors:• Climatic changes• User behaviour• Extraneous heat influence• Influence of hydraulic control devices, etc.The circulating pump designed for maximumload status is adapted by means of a continuoussetpoint/actual-value comparison to the relevantsystem operating state. This automaticcontrol serves to adapt the pump performanceand thus also the power consumption continuouslyto the actual requirement/demand.Electronically controlled pumps from Wilo areable to control the mass flow automatically.This can help avoid throttling and makes anadjustment to the system duty point possible.In addition to the reduced power consumptionof the pump, throttling elements can also bedone without. This way, additional installationand material costs can be noticeably reduced.The same result can be achieved with Wilo controldevices which aren't directly mounted onthe pump.Control mode ∆p-cIn the ∆p-c control mode, the electronics circuitrymaintains the differential pressure generatedby the pump constant at the setpoint valueH S over the permitted volume flow range.Delivery head H [m]∆p-c controln maxn regelH SetpointH Setpoint-min∆p-cFlow Q [m³/h]I. e., any reduction of flow volume (Q) due tothrottling of the hydraulic regulating deviceswill in turn decrease the pump performance tomatch actual system demand by reducing thespeed of the pump. In parallel with speed alteration,the power consumption is reduced to below50 % of the nominal power. The applicationof differential-pressure control requires a variableflow volume in the system. Peak-load operation,e.g. in conjunction with a twin-headpump, will be effected automatically and loadsensitively.If the capacity of the controlledbase-load pump becomes insufficient to coverthe increasing load demand the second pumpwill automatically be started to operate in parallelto cover the risen demand. The variable speedpump will then be run down until reaching thepreset differential-pressure setpoint value.It is generally recommended to pick off the differential-pressuredirectly at the pump and tomaintain it there at a constant level. An alternativewould be to install the signal transmitter inthe system – as a remote signal transmitter inthe so-called index circuit of the system (controlrangeextension). Operation with a remote signaltransmitter will partly allow much larger speed reductionsand thus pump performance reductions.It is essential in this respect that the selectedmeasuring point is valid for the consumptionperformance of all the system sections. Wherethis calculated measuring point in the index circuitmay be subject to shifting to other parts ofthe pipe system, optimisation by means of theWilo DDG impulse selector is preferable. Measuringpoints ranging from 2 to 4 can be comparedon a continuous basis. Only the lowestmeasured value forms the basis for the setpoint/actualvalue comparison by the CR controller.Delivery head H [m]Control curve for remote signal transmittersPump curveSystem curve for themeasuring pointIntersectionpoint =duty pointFlow Q [m³/h]Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 33

PLH_KKK_32_85.QXP 25.05.2007 10:10 Uhr Seite 34PUMP PERFORMANCE CONTROL∆p-v control modeWhen refurbishing or upgrading existing systemsit is not always possible to evaluate thepoint in the circuit which shows the lowest differentialpressure. Original installations havebeen completed years ago and now, after installingindividual room controls, noise problemshave developed. The index circuit of the systemis not known or it is not possible to integratenew sensor connections. A control-range extensionis nevertheless possible using the ∆p-vcontrol mode (recommended for single-pumpsystems).In the ∆p-v control mode, the electronicschange the differential pressure setpoint to bekept by the pump linearly between H S and 1 /2H S . The differential pressure setpoint H changeswith the flow Q.Delivery head H [m]∆p-v controln maxn regelH Setpoint½ H Setpoint∆p-cH Setpoint-minFlow Q [m³/h]Differential pressure – delivery-superimposed (∆p-q)In order to avoid the time and expenditure associatedwith index-circuit evaluation (extensiveand expensive cable routing, amplifiers, etc.),it is possible to superimpose the setpoint differential-pressurevalue directly with a signal proportionalto delivery. Using this method, it ispossible even with multi-pump systems toachieve a control-range extension in spiteof central measured-value acquisition (differentialpressure sensor at the pump). This methodrequires, in addition to the differential pressuresensor which is to be fitted directly on the pumpsystem, the cooling-circuit output or the inputof the consumer rail, the onsite provision bythe customer of a volume-flow transmitter(0/4– 20 mA) to be installed in the system'smain feed pipe.The use of ∆p-q control is recommended forsuch systems whose index circuit or system performanceis not known or in such cases wherelong signal distances cannot be bridged, particularlyfor such systems where volume-flowtransmitters are already available.Delivery head H [%]Differential pressure – delivery-superimposed(∆p-q)∆p = constant∆p = delivery-superimposedFlow volume Q [%]34 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:10 Uhr Seite 35PUMP PERFORMANCE CONTROL∆p-T control modeIn the ∆p-T control mode (programmable onlywith the IR-Monitor) the electronics circuitryvaries the setpoint differential pressure value tobe maintained by the pump as a function of themeasured fluid temperature. This temperatureprompteddifferential-pressure control modecan be used in constant-volume (e.g. one-pipesystems) and variable-flow systems with varyingfeed temperature. Conversely, the ∆p-T controlmode supports heating pump technology, providedthe pump is installed in the return pipe ofthe system.Delivery head H [m]∆p-T controlH maxpos. operationneg. operationH minT max T medH var.T minQ minQ maxFlow Q [m³/h]DDC operating modeIn this mode the actual/setpoint level assessmentrequired for control is referred to a remotecontroller. An analogue signal (0...10 V) is fed asa manipulated variable from the external controllerto the Wilo pumps with built-in electroniccircuitry. The current speed is shown on the display,and manual operation of the pump is deactivated.DDC pump operating mode with built-inelectronic circuitryDDC operation always means that a signal fromthe higher-ordered controller must be registeredby the Wilo products. In addition, floating contactsfor switching on-/off, etc. are required,depending on the used product. Also, floatingsignals or 0...10 V (0/4-20 mA) signals can beused by the Wilo products for monitoring andlogging. Details can be found in the productcatalogues.DDC operating mode with Wilo switchgearn [1/min]n maxSetpoint100%n minOff1 1.5 3 10U [V]When a Wilo control device is used, the setpointdepends on the used signal transmitter. Whenthe signal transmitter DDG 40 is used, this means,for example, that the setpoint at 0 % is equal tozero meters and at 100 % is equal to 40 meters.Analogously, this applies for all other measuringranges.0%0/2 V0/4 mA10 V20 mASignal inputWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 35

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PLH_KKK_32_85.QXP 25.05.2007 10:10 Uhr Seite 37Generator circuits in the liquefier partOn the generator side, one distinguishes between the cooling circuitin open and closed systems. Thus, using a suction well and sinkhole,ground or river water can be utilised for the primary circuit. Or the hotside of the generator is cooled with the air. By means of heat recovery,it is also possible to heat parts of buildings at the same time.Cooling tower/emergency coolerSubmersible pumps supply the condenser directlywith well water. The pumps could also beinstalled in a river or a reservoir. The submersiblepumps must be resistant to water corrosion.They are dimensioned from the delivery head forthe total pressure losses in the condenser circuitand the geodetic head difference between thewell floor and the highest point in the vaporisersystem.Submersible pumps supply the plate heat exchangerdirectly with well water. The pumpscould also be installed in a river or a reservoir.By using stainless steel and/or plastic materialon the primary side of the exchanger, corrosiondamage can be avoided. The refrigerating machinecan be made out of the usual materials.They are dimensioned from the delivery head forthe total pressure losses in the condenser circuitand the geodetic head difference between thewell floor and the highest point in the heat exchangersystem.A cooling tower with collection tray, usually installedon top of the building, takes over heatdissipation out of the condenser. Due to theconstant oxygen supply, pumps made of redbrass or plastic material should be selected.If there is continuous water conditioning,normal cast-iron designs can also be used.They are dimensioned from the delivery headfor the total pressure losses in the condensercircuit and the geodetic head difference betweenthe well floor and the highest point inthe nozzle fitting of the cooling tower.Since this is a closed circuit, standard materialcan be selected. The first filling is to be donewith water according to VDI 2035 etc. to protectagainst deposits and corrosion.Ground water for direct utilisation in the condenserCondenserVaporiserGround water for indirect utilisation in the condenserOpen cooling tower systemCapacitors Vaporiser28°C24°CCapacitors VaporiserClosed cooling tower system in the condenser circuit28°C24°CCondenserVaporiserWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 37

PLH_KKK_32_85.QXP 25.05.2007 10:10 Uhr Seite 38GENERATOR CIRCUITS IN THE LIQUEFIER PARTHeat recoveryIndirect heating with cooling waterMMThe cooling water warmed up in the condenserof the refrigerating machine is used for heatingtasks via a heat exchanger. Due to galvanic insulation,the pump in the condenser circuit is onlyto be designed for these pressure losses. Thematerial selection is arbitrary due to the closedcircuit. If an emergency-cooler is added to thecondenser circuit, the pump is to be determinedbased on its requirements and there must be hydraulicbalancing between the heat exchangerand emergency cooler. To protect against corrosion,the emergency cooling only makes senseas a closed cooling tower.CapacitorsVaporiserGross calorificvalue - gas boilerDirect heating with cooling waterMMThe cooling water warmed up in the condenserof the refrigerating machine is used directly forheating tasks. Due to the direct connection, thepump in the condenser circuit is only to be designedfor the pressure losses in the condenserand pipeline up to the distributor/collector. Thematerial selection is to be adapted to the heatingcircuit. If an emergency-cooler is added tothe condenser circuit, the pump is to be determinedbased on its requirements and there mustbe hydraulic balancing between the heat exchangerand emergency cooler. It's better tosupply the emergency cooler with its own pumpcircuit. To protect against corrosion, the emergencycooling is only possible as a closed coolingtower.CapacitorsVaporiserGross calorificvalue - gas boiler38 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:10 Uhr Seite 39GENERATOR CIRCUITS IN THE LIQUEFIER PARTGeothermal power in the condenser circuitIn the closed circuit between the condenser andheat exchanger line in the ground, the pump isonly to be designed based on these frictional resistances.For reasons of frost protection, it maymake sense to use a mixture of glycol and wateras the fluid. The material properties are to beadapted to these requirements.Ground collector for cooling and for heatstorageCondenserVaporiserIn the closed circuit between the condenser andground spike, the pump is only to be designedbased on these frictional resistances. For reasonsof frost protection, it may make sense touse a mixture of glycol and water as the fluid.The material properties are to be adapted tothese requirements.Ground spikes for cooling and for heat storageCondenserVaporiserWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 39

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PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 41Generator circuits in the vaporiser partIndependent of the basic hydraulic concept, in most cooling systems,there is the requirement that the water mass flow throughthe vaporiser may only deviate from the nominal water mass flowby at most 10%. Otherwise, difficulties can be expected in the controlof refrigerating machines.There is also a danger of freezing when thethroughput is too low. The demand for a constantvaporiser water flow must be met, then,for all changes caused by the air-conditioningcontrol in the load part. Despite this strict requirementfor a constant water volume flow inthe vaporiser, in the recent past, refrigeratingmachines were developed which allow a variablevolume flow. Thus, energy-saving speed-controlledpumps can also be used in the primarycircuit.To realise fault-free operation of cold-waternetworks with several generators and loads, onedivides the network into primary and secondarycircuits.Constant volume flow in the vaporiser circuitAn overflow from the feed to the return of thevalve circuit ensures that the volume flow remainsconstant and that a malfunction in thecontrol of the vaporiser performance is ruledout. The pump is to be dimensioned with respectto the pressure loss on the load which lies in thehydraulically most unfavourable position. On theloads lying in front of it, the water volume is tobe throttled to the nominal power. The volumeflow of the load is to be guaranteed. It might benecessary to select a higher flow to ensure theminimum volume flow in the vaporiser circuit.An overflow from the feed to the return of thedecoupler circuit ensures that the volume flowremains constant and that a malfunction in thecontrol of the vaporiser performance is ruledout. The pump is to be dimensioned based onthe pressure loss in the vaporiser and the resistancesover the decoupler. The volume flow ofthe vaporiser is the required pump flow.Vaporiser circuit with constant volume flow by means of a valve circuitCapacitorsVaporiserM M MVaporiser circuit with constant volume flow by means of hydraulicdecouplersCapacitorsVaporiserWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 41

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 42GENERATOR CIRCUITS IN THE VAPORISER PARTVariable volume flow in the vaporiser circuitVaporiser circuit with variable volume flow via a hydraulic decouplerMMMMCapacitors VaporiserVaporiser circuit with variable volume flow by means of a valve circuitMMMAn overflow from the feed to the return of thedecoupler circuit ensures that the volume flowremains constant and that a malfunction in thecontrol of the vaporiser performance is ruledout. The pump is to be dimensioned based onthe pressure loss in the vaporiser and the resistancesover the decoupler. The volume flow forthe vaporiser capacity is the required pump flow.To ensure the load capacity, the pipeline forconnection to the decoupler might have to bedesigned larger than what the vaporiser capacityrequires. In modern refrigerating machines, thepump capacity can be adapted to the requirementsof the load via temperature regulation.The minimum volume flow for the vaporiser isguaranteed by the speed limitation of the pumpdrive.In some modern refrigerating machines, thepump capacity can be adapted to the requirementsof the load via differential pressure regulation.The minimum volume flow for the vaporiserand/or the pump can be ensured by theoverflow part. The overflow volume must be solarge that it is guaranteed that the supply line tothe load is kept cold. The complete volume flowfor the load and the overflow part for the pumpcapacity must be taken into account. Three-wayvalves in front of the loads are only requiredwhen a longer connection line is necessary.If the connection is near the distribution line,the time until cold fluid is there is usually acceptable.Right now there are only a few possible applicationsfor regulating the pump capacity betweenzero and the nominal volume. On the one hand,cooling generators are not necessarily suitablefor this, and on the other hand, circulationpumps require a minimum volume flow for selfcoolingand self-lubrication. More details canbe found in the respective catalogues.CapacitorsVaporiserVaporiser circuit with variable volume flow over the loadMMCapacitorsVaporiser42 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 43GENERATOR CIRCUITS IN THE VAPORISER PARTCold-water loadThere are two main differences in air-conditioningsystems for room temperature adjustment.Firstly, the temperature of the air (convection),which is fed to the room, is adjusted; secondly,the room temperature is controlled via radiantheat exchangers, such as cooling ceilings or viacomponent tempering. For hydraulic structures,both systems can have a two-, three- or fourpipeconnection.For cold-water transport, there are always onlytwo pipes. The third and fourth pipes are for theheating part so that the temperature in the roomcan be maintained for lower outdoor temperatures.In the three-pipe installation, heating andcooling have a common return. Four-pipe connectionmeans that the cooling and heating partare installed separately up to the heat exchanger.Transmission into the room can only occur viaa common conductor or by one each for heatingor cooling.In the following figures, only the cooling part isshown with a feed and return.Volume flow controlBecause the room load is constantly changingand this is also the case for fresh air, the coolingcapacity is adjusted by means of changing flow.This circuit is only recommendable when thedistribution line is not far away from the load.Usually, all loads may not be connected this way.Not all refrigerating machines or circulatingpumps can work without flow. To avoid damagefrom freezing or dry running, the rerouting ordistribution circuit is to be selected, or at theend of the network there is a controlled overflow.It's possible to control the overflow volumeby a fixed, throttled bypass or a bypass controller.A bypass controller is optimal when theposition of all control valves is monitored, andwhen a volume limit is fallen short of, an overflowsection compensates.The capacity is adjusted to the room load bychanging the flow in the load. In order that onlyso much flows through the bypass as is neededfor temperature maintenance or for maintainingthe required minimum volume for the refrigeratingmachine and/or the pump, a balancing valveis installed in the bypass.Flow rate control with straight-through valveat constant feed temperatureMFlow rate control with distributor valve atconstant feed temperatureMWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 43

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 44C OLD-WATER LOADTemperature controlFlow rate control is not always favourable.The admix circuit can be used for controlleddehumidification and to prevent falling underthe dew point. The feed temperature can beadjusted to the room load and the limits can bekept by measuring the actual value at the criticalpoint of the system. The volume flow in the loadcircuit remains constant.Temperature control with admix valveMThe pump is to be designed according to the capacityand frictional resistances in the load circuit.There should be a differential pressure ofzero on the input side of the control loop. Thiscannot always be achieved in practice, even withcontrolled feeder pumps. For this reason, a differentialpressure controller is to be put in theconnection line of the load circuit without auxiliarypower. In order to retain good load circuitcontrollability and to protect the pump fromdamaging thrust forces, a differential pressure of

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PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 47Observation of constraints forpumps and refrigerating machinesThere are physical limits for all technical devices. The refrigeratingmachines require a volume throughput to prevent icing. If the watervolume which is required for the smallest control level of the vaporiserdoesn't flow, mechanical damage will result without a safetyshutdown.Minimum run-time of refrigeration generators and buffer modeWhen operating with constant water flow, safeoperation is possible when the switch-on/offcycles alternate as seldom as possible. Thismeans that the circulated volume must havesuch a high storage capacity that the minimumrunning time of the cooling generator is exceeded.From experience, one knows that 90 % ofsystems aren't suitable for this without takingadditional measures.Derivation of the specific factor 14.34Q w [kW]m·w =Cpw 4.2KJS· 3600shKJ· K [∆tw]kg · kBufferKJ · kg · K · 3600 s·mw= = 857s · 4.2 KJ · h · Kkgh860kghThe objective is to guarantee economic efficiencyand operating safety, long switch-on/off cycles,and therefore to get long running/idle timesfor the cold-water generator and the hydraulicdecoupling from the cold-water generator andconsumer system. This is possible with a hydraulicdecoupler.This efficiency is enhanced by nozzle pipes andlayering sheets in the tank. The size of the hydraulicdecoupler as a buffer is to be determinedas follows:L 860 kg hkg LFactor = = = 14.34 =min h · 60 min min minWhen there's a change in the specific heat capacity,the specific factor is also to be redetermined.Hydraulic decoupler circuit as bufferSi =kW · F tl · 14.34 · min∆twCapacitorsVaporiserThe minimum system content (Si) depends onkW Nominal cooling capacityF tl Partial load factor for multistagecooling generatorsmin Minimum running time∆tw Temperature differenceCpw Spec. heat capacityWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 47

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 48PROTECTION OF PUMPS AND REFRIGERATING MACHINESHydraulic connection of ice storageValve 2MValve 3MMValve 4Ice bank 1 Ice bank 2MValve 1MValve 5Ice bank pumpCapacitorsVaporiserVaporiser pumpFunction table - ice storage operationOperating modeDischarge ice storageRefrigerating machineon networkDischarge ice storageRefrigerating machineon networkCharge ice storageRefrigerat- Vaporiser Ice stor- Valve 1 Valve 2 Valve 3 Valve 4 Valve 4 Valve 4 Valve 5ing machine pump age pump Gate 1 Gate 2 Gate 3Off Off On Closed Open Open Regulating Regulating Regulating ClosedOn On Off Closed Open Open / / / ClosedOn On On Open Closed Open Regulating Regulating Regulating ClosedOff On Off Open Closed Closed Closed Open Open OpenIce storageAir-conditioning systems with maintenancefreeice storage systems have been built for thepast several years. The refrigerating machineand its connected load, including the recoolingcapacity, is only dimensioned for the basic load.Load peaks over approx. 50 % of the peak loadare covered by the stored ice. Brine serves as aheat carrier. Depending on the system structure,the connection to the house system might bemade via a hydraulic decoupler, or by a systeminsulator (heat exchanger).The switching states of the valves for the respectiveload statuses are shown in the tableabove.since additional flow is forced by the vaporisercircuit, depending on the position of valve 1.Three different load statuses are given for thevaporiser pump. First the refrigerating machineis alone in the network. Only valve 2 is present asa resistance. If peak load operation is required,the resistances from valves 1, 3 and 4 as well asthat of the ice storage are there. If the ice storageis charged, the power losses for valves 1 and5, as well as for the ice storage, are to be overcomeby the vaporiser pump. Based on these requirements,a control of the vaporiser pump overthe volume or temperature is recommended atthe vaporiser outlet.Various flow resistances result from the controlwith effects on the circulating pumps. When theice storage is discharged, the ice storage pumpmust overcome resistances of valves 3 and 4 aswell as that of the ice storage. In peak load operation,another resistance of the ice storagepump is only necessary with large volume flow,48 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 49FUSE PROTECTION OF PUMPS AND REFRIGERATING MACHINESProtection of the refrigerating machine in the vaporiser circuitThe vaporiser circuit is influenced by its circulatingpump. If the pump capacity is too low,the frost protection and/or /flow controllerswitch the refrigerating machine to the malfunctionstate, i.e. "Off". Before the compressoris switched on, the vaporiser pump must beswitched on and have a follow-up time. Circulatingpumps require between 2 seconds and aminute to reach the nominal power, dependingon the ignition/start circuit.In the event of a shutdown, the standard circulatingpump stops in less than 2 seconds. If aphase is missing in three-phase operation, or ifthere is undervoltage, the drive can be operatedwith slippage. The circulating pump runs underits nominal power without a motor protectionrelay releasing. Due to this, and because theflow volume can be throttled by the system orcompressor capacities can be incorrectly controlled,the vaporiser circuit must be equippedwith frost protection and flow controllers. Paddle,differential pressure or volume flow switchescan be used for flow control. In addition, thevaporiser circuit is to be protected from faultystatic and dynamic pressures by a pressurisingsystem and a safety relief valve. In order for theflow volume to be guaranteed during the paralleloperation of several vaporisers with their owncirculating pumps, pipework in accordance withTichelmann or with hydraulic decouplers arerecommendable.Safety requirements for operating cooling generatorsThermalprotectionExpansion valveCondenser ND pressure controlapprox. 15 bar/45 °Capprox. 5 bar/4 °CVaporiser12 °C 6 °CFrost-protection sensorFlow controllerHD pressure controlHot gas sensorThermal protectionPhase sequence relayProtection of the refrigerating machine in the condenser circuitThe setback of the condenser temperature hasoperational limits. Minimum values are requiredfor the function of the refrigerating machine,especially of the expansion valves, and are to begotten from the documentation of the respectivemanufacturer. The temperatures in the condenserdepend on the compressor capacity andthe inlet and outlet temperatures. The coolingwater outlet temperature depends on the circulatedvolume and the inlet temperature. In theusual case, to protect the refrigerating machine,temperature monitoring at the output of thecondenser is sufficient.Under certain circumstances, further safetymeasures are required for protecting the recoolingsystem. Thus, to avoid damage, the inlettemperature in sinkholes or floor heating maynot exceed a maximum permissible value.Quick-acting valves which can close automaticallywithout current might be necessary forthis.Condenser circuit with minimum protectionCapacitorsVaporiserIn addition, the condenser circuit is to be protectedfrom faulty static and dynamic pressures bya pressurising system and a safety relief valve.In order for the flow volume to be guaranteedduring the parallel operation of several vaporiserswith their own circulating pumps, pipeworkin accordance with Tichelmann or with hydraulicdecouplers are recommendable.Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 49

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 50FUSE PROTECTION OF PUMPS AND REFRIGERATING MACHINESProtection of circulating pumpsIf the constraints are not observed, circulatingpumps can be damaged or destroyed by incorrectpressures, fluids, forces, temperatures, circuits,power supplies, vibrations, locations andcontrol-/operating modes.Fluid pressuresThe housing and impeller can be damaged ordestroyed by cavitation due to excessively lowstatic pressure on the suction side of the circulatingpump. The suction connection is also mechanicallydestroyed if oscillations are alsoformed in the suction line due to gas formationor air suctioning. This won't happen directly, butbecomes apparent after a while, depending onthe conditions. In glandless pumps, the bearinglubrication stops and in the case of glandedpumps, the cooling film on the surface of themechanical seal is missing. This can be avoidedby monitoring the inlet pressure with pressuregauges-/or vacuum meters.An excessively high static pressure can cause thehousing to burst or seals to become ineffective.An excessively high contact pressure in mechanicalseals can lead to elevated temperatures andpremature wear in the seal. The pump can beswitched off just to make sure with a maximumpressure controller, or a pressure reducer can beinstalled in front of the pump.Excessively high differential pressures betweenthe suction and pressure side of the pump leadto overheating in the pump compartment due tothe drive energy, which leads to premature wearin the bearings and seals. Efficient operation isnot reachable since the performance in such anoperating situation is low. This can be managedby differential pressure control, pump freewheeling valves or with overflow controllers.The differential pressure between the suctionand pressure side of the pump, which lies to theright outside of the documented manufacturercharacteristic curve, leads to an overload of thedrive and to impermissible forces on the bearing.The lubrication films on the rotating parts whichcome in contact with the fluid are destroyed.This state can be avoided by means of differentialpressure control or volume limiters at thepump.If, for example, a pump is installed after a hydraulicdecoupler as a feeder for a load connectedafter it, it must be made sure that in the caseof a partial load, the residual differential pressureof this pump isn't too high. The load pumpsare then started up and too many run. If such anoperational situation is to be expected, a differentialpressure controller in front of the secondarypump is the solution.FluidIf the planning of the system was done with wateras the heat carrier and if, for whatever reason,brine is filled, the delivery data of the pumpno longer applies. All manufacturers specify theflow rate for water in their catalogues. Overall,a density and viscosity of 1 is assumed. Any deviationfrom this means another flow rate.Abrasive substances in the fluid lead to prematurepump failure. For this reason, water treatedin accordance with VDI 2035 or VDTÜV approvedfluids should be filled. For details, see the cataloguesor offers for the respective types.If, for example, a system was pressurised withwater, emptied and after six weeks was filledup with a commercially available brine, the inhibitorsof the brine will dissolve the rust in thelines and will cause premature wear in the rotatingparts of the pump. In open systems, the fluidis to be subjected to continuously monitoredtreatment and suitable materials are to be selected.If water mixtures are used, the system is to befilled from a premixing tank with the correctmixing ratio. Adding admixtures later will notlead to a sufficient concentration everywhereand energy transport will not be consistent.Also, there is usually an increased danger ofcorrosion.50 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 51FUSE PROTECTION OF PUMPS AND REFRIGERATING MACHINESForcesPumps are installed in pipeline systems whichproduce forces due to temperature expansionsor vibrations, which act directly on the connectionby the flowing fluid. For safety reasons,pumps are to be integrated in the pipeline systemwithout tension in and loads on the connection.The fixed points for the pipes are to beprovided according to the known technical rules.Fluids in their flowing state exert dynamic forcesdue to the direction changes caused by bendsand fittings. For this reason, pumps should beinstalled in stabilising sections, diffusers or rectifierson the suction and pressure side, especiallyin the case of high flow rates.TemperaturesFailing control units make the fluid deviate fromthe design. As a result, cavitation or excessivevolume flows result from excessive fluid temperatures.If the operating temperature of thefluid is lower than planned, the volume flowdrops. In both cases, the drive can be overloadedand the motor protection switches thepump off for safety reasons. Since systems todayare operated without maintenance personnelconstantly there due to cost reasons, it isrecommended to monitor the temperatures withalarm equipment.Ambient pump temperatures act directly on thedrive and the housing. The housings can usuallyaccommodate over- and undertemperatures,but only when they don't occur suddenly. Theelectrodrive can't be operated under 0°C or over40°C without having a special design. Machineinstallation rooms are therefore to be well-ventilatedor cooled. Direct radiated heat on electromotorsis to be prevented.CircuitsMotors for star-/delta start-up may not run permanentlyin the star configuration. 230-voltdrives can't handle 400 volts. Voltages which aretoo low can also lead to electromotor damage.The mains is to be connected appropriately forthe drive (see catalogues).All pumps supply the fluid with energy. This kineticenergy is converted to heat due to theconservation of energy law (nothing is lost).As long as there is a flow, the heat from thepump is transported. When straight-throughvalves or admixing valves of the loads are closed,the conduction of heat is prevented. Thermal insulationand insulation in accordance with energy-savingregulations act like a thermos flaskand the pump compartment heats up.In practice, especially in the cooling sector, thepressurising system is not designed for temperaturesabove 110°C, but these can be exceeded inpumps operating at zero flow. Overflow equipmentwhich allows the fluid to cool can help.It makes more sense to switch off the pump bymonitoring the closing positions of all controlvalves. It is possible to shut down by means of aflow signal transmitter. Here, the pump can beintermittently started again with a forced startup,in order to register the opening of the controlvalves.Parallel pump operation in a hydraulic systemonly works with the same pump capacities unlessa differential pressure controller checks theworking point and only enables the smallerpump when its pressure capacity has beenreached.Series pump operation in a hydraulic system onlyworks with the same pump capacities unless avolume controller checks the working point andonly enables the smaller pump when its volumecapacity has been reached.In a closed system, a pump can convert its completedelivery head into suction. For this reason,the pressurising system must always be on thesuction side of the pump, or there must be acontrol unit in the pump circuit which limits theflow, and therefore reduces the inlet pressure.If this isn't possible due to installation reasons,the configured pressure of the pressurising systemmust be increased by the maximum deliveryhead of the pump at zero volume.Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 51

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 52FUSE PROTECTION OF PUMPS AND REFRIGERATING MACHINESPower supplyPower supplies from the public mains powersupply are subject to certain constraints whichare taken into account in the design of drivesand control units. Voltage drops can occur dueto lines being too long or too thin, which canlead to output deficits and overheating. Controllines and power lines are to be laid separatelydue to induction processes. Systems are to beprotected against overvoltage (e.g. lightning)and to be switched off in the event of undervoltage.Surge arresters and mains monitoringrelays with all-pole insulation of the power supplyprovide solutions.If self-powered systems, mains replacement operationor converter operation are planned, thefollowing conditions must be met:• All Wilo pumps are designed to run on Europeanstandard voltage 230/400 V (±10 %) inaccordance with DIN IEC 60038. They havebeen marked with the CE marking in accordancewith the EU machine directive sinceJanuary 1, 1995. When pumps are utilised in installationswith pumping media temperaturesabove 90°C, a corresponding heat-resistantconnection line must be used.When operating Wilo pumps with control unitsor module accessories, it is essential to adhereto the electrical operating conditions as set outin VDE 0160. When operating glandless andglanded pumps in conjunction with frequencyconvertermodels not supplied by Wilo, it is necessaryto use output filters to reduce motor noiseand prevent harmful voltage peaks and to adhereto the following limit values:• Glandless pumps with P 2 and glandedpumps with P 2 1.1 kW rate of voltagerise du/dt < 500 V/µs, voltage peaks û < 850 V.Installations with large cable lengths (l > 10 m)between converter and motor may cause increasesof the du/dt and û levels (resonance). Thesame may happen for operation with more than4 motor units at one voltage source. The outputfilters must be selected as recommended by theconverter manufacturer or filter supplier, respectively.The pumps must be operated at a maximumof 95 % of their rated motor speed if thefrequency converter causes motor losses. If glandlesspumps are operated on a frequency converter,the following limits may not be fallen shortof at the connection terminals of the pumps:U min = 150 V, f min = 30 HzThe service life and operational reliability of acirculating pump depend to a great extent onthe choice of the correct motor protection device.Motor protection switches are unsuitablefor utilisation in conjunction with multi-speedpumps due to their different nominal currentratings at different speed settings which requirecorrespondingly different fuse protection.All glandless circulating pumps are either• blocking-current proof• provided with internal protection againstunacceptably high winding temperatures• provided with full motor protection throughthermal winding contact and separate relay• provided with full motor protection and builtintrip mechanism (for series, see cataloguedata).• No further motor protection by the customeris required except where this is stipulated forblocking current-proof motors and motorswith internal protection against unacceptablyhigh winding temperatures by the energy supplycompany.Standard glanded pumps are to be protected byonsite motor protection switches with a nominalcurrent setting. Full motor protection is onlyachieved, however, when a thermal winding contactor a PTC thermistor detector is additionallymonitored.If the glanded pump is equipped with a controlmounted to the motor housing, it is equippedwith full motor protection from the manufacturer.The protective measure of protective groundingis to be used for frequency converter controllerswith three-phase current connections. Residualcurrent protective equipment in accordancewith DIN VDE 0664 is not permitted. Exception:Selective universal-current-sensitive residualcurrent circuit breaker (recommended nominalresidual current ∆ = 300 mA).Maximum back-up fuses are to be providedaccording to the onsite installation and theinstalled devices in accordance with DIN/VDE.The maximum permissible cable/wire cross-sectionis to be taken from the catalogues. The ambientoperating conditions are to be taken intoconsideration in selecting the cables. Specialconditions, such as water-pressure tightness orshields, etc. might be required.52 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 53FUSE PROTECTION OF PUMPS AND REFRIGERATING MACHINESVibrationsEvery circulating machine and every flowingfluid generates vibrations. All Wilo pumps arelow-vibration versions. As a result of the system,resonance can occur, and vibrations are amplified.For this reason, please observe the following.Pipelines and pumps should be installed in astress-free condition. The pipelines must befixed in such a way that the pump is not supportingthe weight of the pipeline. In-linepumps are designed for direct horizontal andvertical installation in a pipeline. From a motorpower of 18.5 kW it is not permissible to installthe pump with the pump shaft in a horizontalattitude. On a vertically mounted pump thepipeline must be stress-free and the pump mustbe supported on the pump feet. To suppressvibration amplification, installation on a base isrecommended. Monobloc or standard pumpsare to be mounted on concrete foundations ormounting brackets.Correct selection of the pump base version isone of the factors of decisive importance forlow-noise operation of the pumps. A direct andrigid connection between the pump unit and thebase block is recommended for the purpose ofincreasing the mass capable of absorbing vibrationand for compensating of uncompensatedgravitational forces. Vibration-isolated installationdoes however require at the same time anelastic intermediate layer for separating thefundament block itself from the solidium.The type and the material of the intermediatelayer to be selected depends on a variety ofdifferent factors (and areas or responsibility),including among others rotational speed, aggregatemass and centre of gravity, constructionaldesign (architect) and the development of otherinfluences caused by pipe lines, etc. (planners/installation company).It is recommended - taking into account allstructurally and acoustically relevant criteria -that a qualified building acoustics specialistbe given the task of configuration and designwhere necessary.The external dimensions of the base block shouldbe about 15 to 20 cm longer in the length andwidth than the external dimensions of the pumpunit. Care should be taken to ensure that thedesign of the base pedestal that no acousticbridges are formed by plaster, tile or auxiliaryconstructions that would nullify or sharply reducethe sound insulation effect.Planners/and installation companies must takecare to ensure that the pipe connections to thepump are completely stress-free in their designand unable to exercise any gravitational or vibrationalinfluences on the pump housing whatsoever.Fixed points with no connection to the base arerecommended for the pipe connections on thesuction and pressure sides of the pump.Please also observe thechapter "Pump as a noisegenerator".Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 53

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 54FUSE PROTECTION OF PUMPS AND REFRIGERATING MACHINESSitesThe standard pumps must be protected from theweather and installed in a dry frost -/dust-free,well-ventilated and non-explosive atmosphere.In the case of outdoor installations, special motorsand special corrosion protection are required.The installation of standard pumps with the motorand terminal box facing downwards is notpermissible. Free space (at least about 1.2 mwithout space requirement for material on twosides) is to be provided for dismounting the motor,lantern and impeller. For a nominal motorpower greater than 4 kW, a suitable tackle supportfor installation and maintenance work isrecommended. If the pumps are installed higherthan 1.8 m off the ground, there should be onsiteworking platforms which are permanently installedor which can be set-up any time in mobileform.The minimum dimension for the measuringpoint A d and A s is 2 times the pipe diameter,for U s 5+Nq/53 and for U d 2.5. It is recommendedto install pressure gauges with a test cock.All rated power data and operating values applyat a rated frequency of 50 Hz, a rated voltageof 230 /400 V to 3 kW or 400/ 690 V starting at4 kW, a maximum coolant temperature (KT - airtemperature) of max. 40°C and an installationaltitude of up to 1000 m above mean sea level.For cases outside of these parameters a powerrating reduction must be applied or a larger motoror a higher insulation class must be selected.Borehole and submersible pumps are to have apermanent minimum and maximum water coverage,according to their specifications. Thereshould always be sufficient room for loweringand pulling up the pumps and their pipework.In the case of sump installations, intermediateplatforms for installation and maintenance workmust always be available according to the validaccident prevention regulations.To test the pump capacity, an inlet and outletsection is to be provided in front of and behindthe pump during pipe installation.Minimum distances of the measuring pointsfor checking the pump pressureU dA dDDA sU s54 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 55FUSE PROTECTION OF PUMPS AND REFRIGERATING MACHINESType of controlPumps which serve as admission pressure pumpsare only to be switched on/off when the volumedecrease through the secondary pump circuitlies at the required minimum/ maximum flowvolume. When several admission pressure pumpsare operating in parallel, an automatic switchon/offof the individual pumps within their permittedworking ranges is required.Circulating pumps in secondary circuits are onlyto be switched on when the primary circuit isdelivering the required minimum volume. Theyare to be switched off when the admission pressurepump provides so much pressure that thevolume flow is too high.If there is an on-site, stepless speed control,the minimum and maximum speed are to be limitedso that there is no overloading and the motorself-cooling function is guaranteed. Throttleand bypass controllers in the pump circuit areto be configured so that the maximum and minimumpermitted volume flows are always guaranteed.It makes sense to monitor the fluid temperaturewith an automatic limit shut-downfunction on the pump.The parallel operation of pumps and the simultaneousstepless control of one, several or allpumps is only possible with a load-sensitive,automatic switch-on/off or cut-in functionwithin the permissible limits of the flow anddelivery head of the individual aggregates.In order to avoid malfunctions and damage, theadmission pressure/pressurising system is to bemonitored. Because of the constantly changingpressures in controlled pump circuits, a differentfeed flow is always possible.Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 55

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PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 57Examples for the pump selectionin the condenser circuitWell systemTo conduct heat away from the condenser, a wellsystem has been selected. The brine for the suctionwell lies 10 m under the floor of the installationroom for the refrigerating machine. Due tothe geodetic head difference, a submersiblepump system was selected. A pipeline length of30 m results between the submersible pump andthe connection to the refrigerating machine.The suction side of the condenser lies 2 m underthe highest point of the pipeline to the sinkholeand has a total pipe length of 45 m. The heat capacityis 200 kW and should be conducted awayinto the well system with a temperature differenceof 6 K. The circulated volume is determinedas follows:Formula for volume flow V˙PUFormula for the pressure / the delivery head HH Ges = H geo + H AH A = H VL + H VACalculationH Ges = H geo + H VL + H VAH VL = R · IH VA = ZH VL = 100 · 75ρ · w 2Z = Σζ PaH VL = 7 500 Pa2V·PU =Q· N1.16 · ∆ϑm 3 /hZ = 114.13 ·999.6 · 1 22PaCalculationV·PU =2001.16 · 6V·PU = 28.74 m 3 /hm 3 /hZ = 57 127 PaResultH Ges = H geo + H VL + H VAH Ges = 120 000 Pa + 7 500 Pa + 57 127 PaH Ges = 184 627 PaThe desired pump head results from the pipelinerequirements. The total altitude difference is12 m. The pipeline material is PVC in a nominaldiameter of 100. The R value is 100 Pa/m at aflow rate of about 1 m/s. Based on the installedfittings, bends and the condenser resistance, theaddition of 8 bends, a suction valve and 2 shutoffvalves results in a value of 114.13.AbbreviationDescription1.16 Spec. heat capacity [Wh/kgK]∆Dimensioned temperature difference[K]10-20 K for standard systemsQ NH AH geoH GesH VLH VARHeat demand [kW]Pressure loss of the system in PaGeodetic pressure head difference in Pa (1 m WS ˜ 10 000 Pa)Total pressure loss in PaPipeline pressure loss in PaFitting pressure loss in PaPipe friction resistance in Pa/mLPipe lengthζResistance values in Paρ Density of fluid in kg/m 3w 2 Flow rate in m/s 2ZΣPressure loss in fittings in PaTotal lossesWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 57

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 58EXAMPLES FOR THE PUMP SELECTION IN THE CONDENSER CIRCUITA submersible pump with a flow rate ofQ = 28.74 m 3 /h and H = 18.5 m is to be selected.The selected pump is the Wilo-Sub TWU 6-2403with cooling jacket.Delivery head H [m]40353025201513Operating data specificationsFlow 28.74 m 3 /hDelivery head18.5 mPumped fluidWaterFluid temperature 10 °CDensity 0.9996 kg/dm 3Kinematic viscosity 1.31 mm 2 /s10Vapor pressure0.1 bar50 510 15 20 25 30 35 40Flow Q [m³/h]Hydraulic data (duty point)Flow 31.3 m 3 /hDelivery head20.3 m58 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 59EXAMPLES FOR THE PUMP SELECTION IN THE CONDENSER CIRCUITOpen cooling tower systemThe condenser circuit is cooled via an opencooling tower. At the same capacity of 200 kWand a temperature difference of 5 K, the followingvolume flow results:Formula for the pressure / the delivery head HH Ges = H geo + H AH A = H VL + H VAFormula for volume flow V PUQ· NV·PU =m 3 /h1.16 · ∆ϑCalculationH Ges = H geo + H VL + H VAV·PU =2001.16 · 5V·PU = 34.48 m 3 /hm 3 /hH VL = R · IH VL = 400 · 88H VL = 35 200 PaH VA= ZZ = Σζρ · w 22PaFor the pressure loss calculation, a pipe length of88 m is given with 14 bends, 4 stop valves and analtitude difference of 2.2 m between the minimumwater level and nozzle fitting. PVC pipework isselected with a nominal diameter of 80. This resultsin a resistance coefficient of ζ = 59.7.The result is:Result999.6 · 1.9 2Z = 59.7 ·2Z = 107 230 PaPaH Ges = H geo + H VL + H VAH Ges = 22 000 Pa + 35 200 Pa + 107 230 PaH Ges = 164 430 PaA monobloc pump with a flow rate of Q = 34.48m 3 /h and H = 16.5 m is to be selected.AbbreviationDescription1.16 Spec. heat capacity [Wh/kgK]∆Dimensioned temperature difference[K]10-20 K for standard systemsQ NH AH geoH GesH VLH VARHeat demand [kW]Pressure loss of the system in PaGeodetic pressure head difference in Pa (1 m WS ˜ 10 000 Pa)Total pressure loss in PaPipeline pressure loss in PaFitting pressure loss in PaPipe friction resistance in Pa/mLPipe lengthζResistance values in Paρ Density of fluid in kg/m 3w 2 Flow rate in m/s 2ZΣPressure loss in fittings in PaTotal lossesWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 59

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 60EXAMPLES FOR THE PUMP SELECTION IN THE CONDENSER CIRCUITThe selected pump is the Wilo-CronoBloc-BL 40/130-3/2 with red brass impeller.Cavitation can be ruled out since the water levelin the cooling tower is about 12 m above thepump inlet. The fluid must constantly be saltedand treated due to the corrosion and legionellaproblem.Shaft power P2 [kW] Efficiency [%]NPSH [m]Delivery head H [m]262422201816141210842100 4 8 12841ø 12616 20 24 28 32 36 40 44 48 52 56 60 64 68Flow Q [m³/h]ø 12620 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68806040Flow Q [m³/h]ø 126200 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68432Flow Q [m³/h]ø 12610 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68Flow Q [m³/h]Operating data specificationsFlow 34.48 m 3 /hDelivery head16.5 mPumped fluidWaterFluid temperature 32 °CDensity 0.9951 kg/dm 3Kinematic viscosity 0.7605 mm 2 /sVapor pressure0.1 barHydraulic data (duty point)Flow 37.3 m 3 /hDelivery head19 mShaft power P22.51 kWSpeed2000 rpmNPSH3.43 mImpeller diameter 125 mm60 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 61EXAMPLES FOR THE PUMP SELECTION IN THE CONDENSER CIRCUITClosed cooling tower systemBased on its being winter-proof, the capacityof 200 kW is recooled via a closed cooling tower.Antifrogen L having a concentration of 40 %to 60 % water is filled for frost protection.Formula for the pressure / the delivery head HH Ges = (H geo + H A ) · f pH A = H VL + H VAFormula for volume flow V PUQ· NV·PU =m 3 /h1.04 · ∆ϑCalculationH Ges = (H geo + H VL + H VA ) · f pCalculationH VL= R · IH VA= ZV·PU =2001.04 · 5V·PU = 38.46 m 3 /hm 3 /hH VL = 400 · 88H VL= 35 200 Paρ · w 2Z = Σζ · Pa21 034 · 1.9 2Z = 59.7 ·2PaA pipe length of 88 m is given for calculating thepressure loss, with 14 bends and 4 stop valves.PVC pipework is selected with a nominal diameterof 80. This results in a resistance coefficientof = 59.7. The result is:ResultH Ges = (H geo + H VL + H VA ) · f pZ = 111 422 PaH Ges = (0 + 35 200 Pa + 111 422 Pa) · 1.36H Ges = 199 406 PaA monobloc pump with a flow rate ofQ = 38.46 m 3 /h and H = 19.9 m is selected.Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 61

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 62EXAMPLES FOR THE PUMP SELECTION IN THE CONDENSER CIRCUITThe selected pump is the Wilo-CronoBloc-BL 40/140-4/2.Cavitation can be ruled out since this is a closedcircuit. The diaphragm extension vessel is to bedetermined for a volume expansion of 2 to 5 %.Shaft power P2 [kW] Efficiency [%]NPSH [m]Delivery head H [m]302826242220181614121086420 4 8 121ø 13816 20 24 28 32 36 40 44 48 52 56 60 64 68Flow Q [m³/h]10864ø 13820 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68Flow Q [m³/h]1008060ø 13840200 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68Flow Q [m³/h]54ø 1383210 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68Flow Q [m³/h]Operating data specificationsFlow 38.46 m 3 /hDelivery head19.9 mPumped fluid Antifrogen L (40 %)Fluid temperature 27 °CDensity 1.039 kg/dm 3Kinematic viscosity 5.963 mm 2 /sVapor pressure0.1 barHydraulic data (duty point)Flow 41.3 m 3 /hDelivery head23.1 mShaft power P22.57 kWSpeed2000 rpmNPSH3.67 mImpeller diameter 138 mm62 Subject to change without prior notice 02/2006 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 63EXAMPLES FOR THE PUMP SELECTION IN THE CONDENSER CIRCUITHeat recovery via building heating and hot water productionIn the case of heat recovery, the flow rate can bedetermined with a larger temperature difference.A difference of 20 K is reasonable. At the samecapacity of 200 kW and a temperature differenceof 20 K, the following volume flow results:Formula for volume flow V PUFormula for the pressure / the delivery head HH Ges = H geo + H AH A = H VL + H VACalculationV·PU =Q· N1.16 · ∆ϑm 3 /hH Ges = H geo + H VL + H VACalculationV·PU =2001.16 · 20V·PU = 8.62 m 3 /hm 3 /hH VL = R · IH VL = 160 · 36H VL = 5 760 PaH VA= Zρ · w 2Z = Σζ · Pa2977.7 · 0.98 2Z = 74.9 ·2PaSteel pipework is selected with a pipe length of36 m with a nominal diameter of 50, with 8 bendsand 4 flat slide valves. This results in a resistancecoefficient of = 74.9. The result is:ResultH Ges = H geo + H VL + H VAZ = 35 165 PaH Ges = 0 + 5 760 Pa + 35 165 PaH Ges = 40 925 PaTo minimise maintenance costs, a glandlesspump with a flow rate of Q = 8.62 m 3 /h andH = 4.09 m is selected.AbbreviationDescription1.16 Spec. heat capacity [Wh/kgK]∆Dimensioned temperature difference[K]10-20 K for standard systemsQ NH AH geoH GesH VLH VARHeat demand [kW]Pressure loss of the system in PaGeodetic pressure head difference in Pa (1 m WS ˜ 10 000 Pa)Total pressure loss in PaPipeline pressure loss in PaFitting pressure loss in PaPipe friction resistance in Pa/mLPipe lengthζResistance values in Paρ Density of fluid in kg/m 3w 2 Flow rate in m/s 2ZΣPressure loss in fittings in PaTotal lossesWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 63

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 64EXAMPLES FOR THE PUMP SELECTION IN THE CONDENSER CIRCUITThe selected pump is the Wilo-TOP-S 50/43-PN 6/10.Cavitation can be ruled out since this is a closedcircuit. For protection, the condenser circuitshould have its own safety valve and beequipped with its own diaphragm extensionvessel for a volume expansion of 2 to 5 %.Delivery head H [m]5,04,54,03,53,02,52,01,511,00,50 5min2max10 15 20 25 30Flow Q [m³/h]Note!The pump must constantly circulate the requiredwater volume when the refrigerating machine isin operation. This is to be ensured by a hydraulicswitch, heat exchanger, differential pressurevalves or bypasses.Operating data specificationsFlow 8.62 m 3 /hDelivery head4.09 mPumped fluidWaterFluid temperature 70 °CDensity 0.9777 kg/dm 3Kinematic viscosity 0.4084 mm 2 /sVapor pressure0.3121 barHydraulic data (duty point)Flow 8.88 m 3 /hDelivery head4.3 mPower consumption P1 0.295 kWSpeed2600 rpmThe necessary cooling towers are to be designedwith their own pump, as described before. Whenantifreeze is added, system separation with heatexchangers is recommended.64 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 65EXAMPLES FOR THE PUMP SELECTION IN THE CONDENSER CIRCUITGround collector systemTo protect against freezing, the system is filledwith a glycol mixture (40% Antifrogen N + 60%water). The circulated volume is determined asfollows:Formula for the pressure / the delivery head HH Ges = (H geo + H A ) · f pH A = H VL + H VAFormula for volume flow V PUQ· NV·PU =m 3 /h0.97 · ∆ϑCalculationH Ges = (H geo + H VL + H VA ) · f pCalculationH VL= R · IH VA= Z + collector resistanceV·PU =2000.97 · 6m 3 /hH VL = 50 · 75H VL= 3 750 PaZ = Σζ ·ρ · w 22PaV·PU = 34.29 m 3 /hZ = 109.63 ·1 070 · 0.8 22PaThe desired pump head results from the pipelinerequirements. PVC pipeline material is selectedwith a nominal diameter of 125. The R value is50 Pa/m at a flow rate of about 0.8 m/s. Basedon the installed fittings, bends and the condenserresistance, the addition of 8 bends and2 shut-off valves results in a value of 109.63.Another 20 kPa are to be included in the calculationfor the collector and the pipe length to beconsidered is 75 m.Z = 37 537 PaResultH Ges = (H geo + H VL + H VA ) · f pH Ges = (0 + 3 750 Pa + 57 537 Pa) · 1.47H Ges = 90 092 PaA pump with a flow rate of Q = 34.29 m 3 /h andH = 9.0 m is to be selected.AbbreviationDescription1.16 Spec. heat capacity [Wh/kgK]∆Dimensioned temperature difference[K]10-20 K for standard systemsQ NH AH geoH GesH VLH VARHeat demand [kW]Pressure loss of the system in PaGeodetic pressure head difference in Pa (1 m WS ˜ 10 000 Pa)Total pressure loss in PaPipeline pressure loss in PaFitting pressure loss in PaPipe friction resistance in Pa/mLPipe lengthζResistance values in Paρ Density of fluid in kg/m 3w 2 Flow rate in m/s 2ZΣPressure loss in fittings in PaTotal lossesWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 65

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 66EXAMPLES FOR THE PUMP SELECTION IN THE CONDENSER CIRCUITThe selected pump is the Wilo-CronoLine-IL 65/170-1.5/4.Cavitation can be ruled out since this is a closedcircuit. For protection, the condenser circuitshould have its own safety valve and be equippedwith its own diaphragm extension vesselfor a volume expansion of 5 to 7 %.Delivery head H [m]121110987Operating data specificationsFlow 34.29 m 3 /hDelivery head9 mPumped fluid Antifrogen N (40%)Fluid temperature 10 °C654321Ø 173Density 1.073 kg/dm 3Kinematic viscosity 4.507 mm 2 /sVapor pressure0.1 bar10 510 15 20 25 30 35 40 45 50 55 60 65Flow Q [m³/h]Hydraulic data (duty point)Flow 34.7 m 3 /hDelivery head9.22 mShaft power P21.31 kWSpeed1450 rpmNPSH2.39 mImpeller diameter173 mm66 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 67EXAMPLES FOR THE PUMP SELECTION IN THE CONDENSER CIRCUITGround spike systemThe closed circuit of a ground spike system isspecified with a pressure loss of 3.1 m. The pressurefor the condenser (2 m) is to be added.The pump must achieve a delivery head of atleast 5.1 m.To protect against freezing, the system is filledwith a glycol mixture (40 % Tyfocor L and 60 %water). The circulated volume is determined asfollows:Formula for volume flow V PUV·PU =CalculationV·PU =Abbreviation Description0.97 Spec. heat capacity [Wh/kgK]∆Dimensioned temperature difference[K]2-6 K for standard systemsQ NQ· N1.01 · ∆ϑ2001.01 · 4V·PU = 49.32 m 3 /hm 3 /hm 3 /hA pump with a flow rate of Q = 49.32 m 3 /h andH = 5.1 m is to be selected.Heat demand [kW]The selected pump is the Wilo-CronoBloc-BL 80/150-1.5/4.Cavitation can be ruled out since this is a closedcircuit. For protection, the condenser circuitshould have its own safety valve and be equippedwith its own diaphragm extension vesselfor a volume expansion of 5 to 7 %.Delivery head H [m]76,565,554,543,532,521,510,50 101Ø 14420 30 40 50 60 70 80 90 100 110 120 130Flow Q [m³/h]Operating data specificationsFlow 49.32 m 3 /hDelivery head5.1 mPumped fluid Tyfocor L (40%)Fluid temperature 10 °CDensity 1.045 kg/dm 3Kinematic viscosity 6.604 mm 2 /sVapor pressureHydraulic data (duty point)0.1 barFlow 52.6 m 3 /hDelivery headShaft power P2SpeedNPSHImpeller diameter5.78 m1.41 kW1450 rpm2.54 m144 mmWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 67

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 68Examples for the pump selectionin the cold water circuitFlow rate control with straight-through valvesFlow rate control with straight-throughvalves and pump performance adjustmentThe pressure loss of the system (4.65 m) is takenas the maximum pump head from a pipeworkcalculation. Due to the main pressure loss of 3 min the individual load circuit, a pump which hasconstant pressure regulation is to be selected.65 kW6 °CM12 °CMMM37 kW125 kWDelivery head H [m]14131211 10 m10max9 8 m87 6 m65 4 m43210 52 m10min15 20 25 30 35 40 45Flow Q [m³/h]The flow is determined as follows:Formula for volume flow V˙PUQ· NV·PU =m 3 /h1.16 · ∆ϑPower consumption P1 [kW]0,90,8max0,710 m0,68 m0,56 m0,40,34 m0,22 mmin0,10 5 10 15 20 25 30 35 40 45Flow Q [m³/h]Abbreviation Description1.16 Spec. heat capacity [Wh/kgK]∆Dimensioned temperature difference[K]10-20 K for standard systemsQ NCalculationV·PU =2271.16 · 6V·PU = 32.61 m 3 /hHeat demand [kW]m 3 /hOperating data specificationsFlow 32.61 m 3 /hDelivery head4.65 mPumped fluidWaterFluid temperature 6 °CDensity 0.9999 kg/dm 3Kinematic viscosity 1.474 mm 2 /sVapor pressure0.1 barHydraulic data (duty point)Flow 32.6 m 3 /hDelivery head4.65 mPower consumption P1 0.699 kW68 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 69EXAMPLES FOR THE PUMP SELECTION IN THE COLD WATER CIRCUITWilo-Stratos 65/1-12 PN 6/10 is the choice.This pump is low-maintenance and works withlittle energy. To protect against corrosion bycondensation water, the pump is equipped witha Wilo-ClimaForm.By monitoring the open position of the controlvalves, the pump is to be switched off when thevalves are closed to protect against running dry.If this isn't possible, for example because thedistances of the distributor line are too long, anoverflow of 10% is to be permanently ensuredat the ends of the distributor line (see short sectionin the schematic diagram). Note: It may benecessary to dimension the pump larger!Cavitation can be ruled out since this is a closedcircuit. For protection, the vaporiser circuit shouldhave its own safety valve and be equipped withits own diaphragm extension vessel for a volumeexpansion of 5 to 7 %.Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 69

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 70EXAMPLES FOR THE PUMP SELECTION IN THE COLD WATER CIRCUITFlow rate control with distributor valveFlow rate control with distributor valves andpump performance adjustmentSince a long pipe section is to be overcome upto the loads, a ∆p-v controlled pump can be selected.In the load circuit, only 4 m is requiredfrom the 8.2 m delivery head of the pump.18 °CMMMM55 kW45 kW125 kWDelivery head H [m]14131211109876543210 512 mmax10 m8 m6 m4 mmin10 15 20 25 30 35 40 45 50 55 60 65 70Flow Q [m³/h]23 °CFor maintaining the temperature in the controlledsystem of the load, a flow rate controlwith distributor valves is selected. The pumprequires a flow of 10% at the duty point forthe smallest load, which is ensured via throttlevalves or volume limiters in the admix line.Power consumption P1 [kW]1,81,61,41,210,80,60,40,20 512 m10 m8 m6 m4 mminmax10 15 20 25 30 35 40 45 50 55 60 65 70The flow is determined as follows:Flow Q [m³/h]Formula for volume flow V˙PUQ· NV·PU =m 3 /h1.16 · ∆ϑAbbreviation Description1.16 Spec. heat capacity [Wh/kgK]∆Dimensioned temperature difference[K]10-20 K for standard systemsQ NHeat demand [kW]Operating data specificationsFlow 38.79 m 3 /hDelivery head8.2 mPumped fluidWaterFluid temperature 18 °CDensity 0.9966 kg/dm 3Kinematic viscosity 1.053 mm 2 /sVapor pressure0.1 barHydraulic data (duty point)Flow 38.8 m 3 /hDelivery head8.2 mPower consumption P1 1.34 kWCalculationV·PU =2271.16 · 5m 3 /hV·PU = 38.79 m 3 /h70 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 71EXAMPLES FOR THE PUMP SELECTION IN THE COLD WATER CIRCUITOnly the Wilo-Stratos 80/1-12 is a good choiceconsidering the low maintenance and operatingcosts. The setpoint curve to be adjusted in thecontrolled state runs between 8.6 m (max. speed)and 4.3 m (min. control speed). This guaranteesthat only a maximum of 10% of the dimensionedvolume flows for maintaining the temperature inthe distributor circuit when the bypass section iscorrectly configured.Cavitation can be ruled out since this is a closedcircuit. For protection, the vaporiser circuit shouldhave its own safety valve and be equipped withits own diaphragm extension vessel for a volumeexpansion of 5 to 7 %.Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 71

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 72MEXAMPLES FOR THE PUMP SELECTION IN THE COLD WATER CIRCUITAdmixing circuit for temperature controlAdmixing circuit with three-way valves andpump performance adjustment18 °CMMM250 kWThe pumping pressure of 16.5 m is taken fromthe pipework calculation. To protect from frost,the system is operated with a Tyfocor/watermixture (40 % to 60 %). To stabilise the valveauthority at the load controllers, a constantdifferential pressure is demanded at the pump.Instead of a differential pressure valve or a differentialpressure controller without auxiliarypower, only a controlled pump for energeticallyfavourable operation is taken into consideration.MM75 kW450 kWDelivery head H [m]36322824201632 m24 m16 m22 °C12848 m1For optimum power adjustment, an admixingcircuit directly on the load was selected. Temperaturemaintenance is not required for theload circuit. The required volume flow is determinedas follows:Formula for volume flow V˙PUV·PU =Abbreviation Description1.03 Spec. heat capacity [Wh/kgK]∆Dimensioned temperature difference[K]10-20 K for standard systemsQ NCalculationV·PU =Q· N1.03 · ∆ϑ7751.03 · 4V·PU = 188.11 m 3 /hm 3 /hHeat demand [kW]m 3 /hNPSH [m]Shaft power P2 [kW]1210864202824201612840Operating data specificationsFlow 188.1 m 3 /hDelivery head16.5 mPumped fluid Tyfocor L (40%)Fluid temperature 18 °CDensity 1.061 kg/dm 3Kinematic viscosity 4.14 mm 2 /sVapor pressureHydraulic data (duty point)1 barFlow 188 m 3 /hDelivery headPower consumption P1NPSH0 40Impeller diameterMinimum volume flow80 120 160 200 240 280 32016.5 m13.1 kW6.58 m0 mmFlow Q [m³/h]40 80 120 160 200 240 280 320Flow Q [m³/h]40 80 120 160 200 240 280 320Flow Q [m³/h]20 m 3 /h at ∆p=16.5 m72 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 73EXAMPLES FOR THE PUMP SELECTION IN THE COLD WATER CIRCUITThe selected Wilo-CronoLine-IL-E 100/8-33BF R1 requires a minimum circulation of 20 m 3 /h,which is to be ensured with overflow sections.If the opening positions of the load controllersare set above 90% to admixing, differentialpressure valves are opened by electromotors toprotect the pump.Cavitation can be ruled out since this is a closedcircuit. For protection, the vaporiser circuit shouldhave its own safety valve and be equipped withits own diaphragm extension vessel for a volumeexpansion of 5 to 7 %.Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 73

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 74Examples for the pump selectionin the vaporiser circuitVaporiser circuit with constant volume flowThe circuit of a load system is specified witha pressure loss of 13.1 m. The pressure for thevaporiser (5 m) is to be added. The pump mustachieve a delivery head of at least 18.1 m.Distribution connection in the vaporiser circuitin front of the loadsCapacitorsThe circulated volume is determined as follows:Formula for volume flow V˙PUV·PU =Abbreviation Description1.16 Spec. heat capacity [Wh/kgK]∆Dimensioned temperature difference[K]2-12 K for standard systemsQ NV·PU =VaporiserCalculationQ· N1.16 · ∆ϑ2001.16 · 6V·PU = 28.74 m 3 /hm 3 /hHeat demand [kW]m 3 /hM M MA pump with a flow rate of Q = 28.74 m 3 /h andH = 18.1 m is to be selected.The selected pump is the Wilo-CronoLine-IL 50/260-3/4.Cavitation can be ruled out since this is a closedcircuit. For protection, the vaporiser circuit shouldhave its own safety valve and be equipped withits own diaphragm extension vessel for a volumeexpansion of 5 to 7 %.Delivery head H [m]302520151050 51Ø 25510 15 20 25 30 35 40 45Flow Q [m³/h]Operating data specificationsFlow 28.74 m 3 /hDelivery headPumped fluid18.1 mWaterFluid temperature 16 °CDensity 0.9989 kg/dm 3Kinematic viscosity 1.11 mm 2 /sVapor pressureHydraulic data (duty point)0.1 barFlow 29 m 3 /hDelivery headShaft power P2SpeedNPSHImpeller diameter18.4 m2.66 kW1450 rpm2.56 m255 mm74 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 75EXAMPLES FOR THE PUMP SELECTION IN THE VAPORISER CIRCUITHydraulic decoupler in vaporiser circuitThe circuit of a vaporiser system, including thehydraulic decoupler, is specified with a pressureloss of 5.85 m. The pump must achieve a deliveryhead of at least 5.85 m. The circulated volume isdetermined as follows:Hydraulic decoupler in vaporiser circuitFormula for volume flow V˙PUV·PU =Q· N1.16 · ∆ϑm 3 /hCapacitorsVaporiserAbbreviation Description1.16 Spec. heat capacity [Wh/kgK]∆Dimensioned temperature difference[K]2-12 K for standard systemsQ NHeat demand [kW]To minimise the operating and maintenancecosts, a glandless pump, Wilo-Stratos 80/1-12,is selected. It is advantageous that this pumpcircuit does not have to be equipped with a regulationvalve for the concrete duty point setting.This is set using the reference value control ofthe pump.Calculation223V·PU =1.16 · 4m 3 /hCavitation can be ruled out since this is a closedcircuit. For protection, the vaporiser circuit shouldhave its own safety valve and be equipped withits own diaphragm extension vessel for a volumeexpansion of 5 to 7 %.V·PU = 48.1 m 3 /hA pump with a flow rate of Q = 43.1 m 3 /h andH = 5.85 m is to be selected.Delivery head H [m]14131211109876543210 512 m max10 m8 m6 m4 mmin2 m10 15 20 25 30 35 40 45 50 55 60 65 70Flow Q [m³/h]Operating data specificationsFlow 48.1 m 3 /hDelivery head5.85 mPumped fluidWaterFluid temperature 16 °CDensity 0.9989 kg/dm 3Kinematic viscosity 1.11 mm 2 /sVapor pressure0.1 barHydraulic data (duty point)Flow 48.1 m 3 /hDelivery head5.85 mPower consumption P1 1.37 kWWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 75

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 76EXAMPLES FOR THE PUMP SELECTION IN THE VAPORISER CIRCUITVaporiser circuit with ice storageTo ensure the functional sequence, anAntifrogen L / water mixture (40 % to 60 %)is selected as the fluid to be pumped.The volume flow is determined as follows:Formula for volume flow V˙PUStep 1(15.41) 0.50B = 2.80 · 3.49(32.68) 0.25 · (9) 0.125V·PU =Q· N1.02 · ∆ϑm 3 /hStep 2C Q ≈ C H ≈ (2.71) -0.165 · (log 3.49)3.15 ≈ 0.98Abbreviation Description1.02 Spec. heat capacity [Wh/kgK]∆Dimensioned temperature difference[K]10-20 K for standard systemsQ NHeat demand [kW]CalculationStep 332.68Q W = = 33.48 m 3 /h0.9769H W = = 9.22 m0.98V·PU =1001.02 · 3m 3 /hV·PU = 32.68 m 3 /hThe system pressure losses are assumed to be9 m from the calculation model. The preliminarypump data is to be determined with the followingsteps.Ice storage operation with 100 kW and a fluid temperature of -4° CValve 2MValve 3MValve 4MIce bank 1 Ice bank 2MValve 1MValve 5Ice bank pumpCapacitorsVaporiserVaporiser pump76 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 77EXAMPLES FOR THE PUMP SELECTION IN THE VAPORISER CIRCUITStep 4Wilo-Stratos 80/1-12 in ice storage modeat 100 kWStep 5C η = 3.49 -(0.0547 · 3.490.69) = 0.85Delivery head H [m]Power consumption P1 [kW]141312 12 m max111098710 m8 m6546 m4 m3min2 2 m10 5 10 15 20 25 30 35 40 45 50 55 60 65 701,81,61,41,210,80,60,40,212 m10 m8 m6 m4 m2 mminFlow Q [m³/h]maxη vis = 0.85 · 0.66 = 0.56Step 633.48 · 9.22 · 1.053P vis = = 1.58 kW367 · 0.56The selected Wilo-Stratos 80/1-12 is dimensionedat its capacity limit. It isn't possible to reducethe operating temperature to under -4°C. Operationat -3°C at otherwise the same original datais better.Cavitation can be ruled out since this is a closedcircuit. For protection, the vaporiser circuit shouldhave its own safety valve and be equipped withits own diaphragm extension vessel for a volumeexpansion of 5 to 7 %.0 510 15 20 25 30 35 40 45 50 55 60 65 70Flow Q [m³/h]Operating data specificationsFlow 33.48 m 3 /hDelivery head9.22 mPumped fluidWaterFluid temperature 20 °CDensity 0.9982 kg/dm 3Kinematic viscosity 1.001 mm 2 /sVapor pressure0.1 barHydraulic data (duty point)Flow 33.5 m 3 /hDelivery head9.22 mPower consumption P1 1.34 kWVapor pressure0.1 barMotor DataNominal power P2 1.3 kWPower consumption P1 1.57 kWRated motor speed 3300 rpmNominal voltage11.34 kW ~ 230 V, 50 HzMax. current consumption 6.8 AProtection class IP 44Permitted voltage tolerance +/- 10Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 77

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 78EXAMPLES FOR THE PUMP SELECTION IN THE VAPORISER CIRCUITVaporiser circuit with variable volume flowHydraulic decoupler in the vaporiser circuitwith temperature regulation for the circulatingpumpThe circuit of a vaporiser system, including thehydraulic decoupler, is specified with a pressureloss of 5.85 m. The pump must achieve a deliveryhead of at least 5.85 m. Due to the stepped poweradjustment of the vaporiser, its flow capacitycan be changed between 30 % and 100 %.Hydraulic decoupler in the vaporiser circuit with temperature regulationfor the circulating pumpA pump with a flow rate of Q = 43.1 m 3 /h andH = 5.85 m is to be selected.Delivery head H [m]14131211109876543210 512 m max10 m8 m6 m4 mmin2 m10 15 20 25 30 35 40 45 50 55 60 65 70Flow Q [m³/h]CapacitorsVaporiserThe circulated volume is determined as follows:Operating data specificationsFlow 43.1 m 3 /hDelivery headPumped fluid5.85 mWaterFluid temperature 16 °CDensity 0.9989 kg/dm 3Kinematic viscosity 1.11 mm 2 /sVapor pressure0.1 barFormula for volume flow V˙PUV·PU =Q· N1.16 · ∆ϑm 3 /hHydraulic data (duty point)Flow 48.1 m 3 /hDelivery headPower consumption P15.85 m1.37 kWAbbreviation Description1.16 Spec. heat capacity [Wh/kgK]∆Dimensioned temperature difference[K]2-12 K for standard systemsQ NCalculationV·PU =2001.16 · 4V·PU = 43.1 m 3 /hHeat demand [kW]m 3 /hTo minimise the operating and maintenancecosts, a glandless pump, a Wilo-Stratos 80/1-12with a LON module, is selected. It is advantageousthat this pump circuit doesn't have to beequipped with a regulation valve for the concreteduty point setting. Adjustment is donewith a machine controller. The pump is specifiedappropriately for the cooling capacity and fluidtemperature of the required setpoint. A manualcontrol mode of the pump is also possible. Everydesired flow between 20 m 3 /h and 48.1 m 3 /h canbe set by concretely specifying a speed.Cavitation can be ruled out since this is a closedcircuit. For protection, the vaporiser circuit shouldhave its own safety valve and be equipped withits own diaphragm extension vessel for a volumeexpansion of 5 to 7 %.78 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 79EXAMPLES FOR THE PUMP SELECTION IN THE VAPORISER CIRCUITDistributor circuit and variable volume flow inthe vaporiser circuitDistributor circuit and variable volume flow in the vaporiser circuitIn the common circuit of the vaporiser and loads,the flow volume can be variably adapted to thedemands. The vaporiser may be operated between17.5 m 3 /h and 43.1 m 3 /h. The resistancesin the distributor line up to the first outlet of anascending pipe, including the vaporiser, amountto 9.0 m. 3.0 m are required at full capacity forthe connection of the ascending pipes, includingloads.Based on the declining pressure demand in thegenerator part, a delivery head of 4.48 m is requiredat a flow rate of 17.3 m 3 /h.MMMCapacitorsVaporiserA Wilo-VeroLine-IP-E 80/115-2.2/2 was selected.By means of an onsite controller, the pump canbe specified to the operating requirements ofthe adapted setpoint. Alternatively, the ascendingpipe – with the greatest pressure demandin the generator part and feeder pipe – can beequipped with a differential pressure sensor.The control curve is shown in red in the figureto the right.Delivery head H [m]1816141210864212 m8 m4 mThe demanded minimum volume flow of 17.5 m 3 /his guaranteed by presetting the distributor andbypass volumes.010 20 30 40 50 60 70 80 90Flow Q [m³/h]Cavitation can be ruled out since this is a closedcircuit. For protection, the vaporiser circuitshould have its own safety valve and beequipped with its own diaphragm extension vesselfor a volume expansion of 5 to 7 %.Operating data specificationsFlow 43.1 m 3 /hDelivery head12 mPumped fluidWaterFluid temperature 16 °CDensity 0.9989 kg/dm 3Kinematic viscosity 1.11 mm 2 /sVapor pressure0.1 barHydraulic data (duty point)Flow 43.1 m 3 /hDelivery head12 mShaft power P2kWSpeed2880 rpmNPSH1.99 mImpeller diameter 115 mmWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 79

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 80EXAMPLES FOR THE PUMP SELECTION IN THE V- CIRCUITVaporiser circuit with measuring orificeFlow rate control in the vaporiser circuitVaporisers which have a distributor pump andmixing circuit pumps in their hydraulic systemcan have different flows. In order to maintaingood controllability of the circuit, a constantvolume flow is required under certain preconditions.By means of a measuring orifice and apressure transducer, the pump can keep theflow constant within its duty chart.At a power reduction of 350 kW cooling capacity,a volume flow of 50 m 3 /h is required. If all secondarycircuits are closed, this volume flows viathe short circuit. If all secondary circuits pull waterout of the primary circuit, an additional differentialpressure of 3 m is created. This meansthat the primary circuit pump no longer has tobuild up a differential pressure of 5.8 m, but onlyof 2.8 m.Delivery head H [m]141312 12 m max111098710 m8 m6543216 m4 mmin2 m0 5 10 15 20 25 30 35 40 45 50 55 60 65 70Operating data specificationsFlow 50 m 3 /hDelivery headPumped fluid5.8 mWaterFluid temperature 6 °CDensity 0.9989 kg/dm 3Kinematic viscosity 1.474 mm 2 /sVapor pressure0.1 barFlow Q [m³/h]Secondary circuitM16°C18°CHydraulic data (duty point)Flow 50 m 3 /hDelivery head5.8 mPower consumption P1 1.45 kWVaporiser∆pPrimary circuitM M M M M M6°C12 °CThe selected Wilo-Stratos 100/1-12 keeps thevolume flow constant (within the regulation differenceof the PID controller) in connection witha Wilo CRn system. The differential pressure iskept constant via the measuring orifice; a constantvolume flow is automatically set. The valvein the bypass is to be set so that only 50 m 3 /hflow through this at full speed. In the controlrange of the reduction in the secondary circuits,a pressure drop is created in the feed and a pressurerise in the return. As a result, the flow viathe bypass valve will approach zero.Cavitation can be ruled out since this is a closedcircuit. For protection, the vaporiser circuit shouldhave its own safety valve and be equipped withits own diaphragm extension vessel for a volumeexpansion of 5 to 7 %.80 Subject to change without prior notice 02/2007 WILO AG

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PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 83Economical consideration in theselection of fittingsDifferent components always belong to a coldwaterinstallation which must be planned anddimensioned specifically for fulfilling the posedair-conditioning or cooling tasks - each separately,especially in interconnected systems.The engineer must also consider the economicconstraints at an early point in time. On the onehand, the investment costs, and on the otherhand, also the later operating costs and measureswhich minimise these. Here, the respectiveefficiencies of the components and of the overallsystem play a decisive role: Because, dependingon the load status (full load / partial load) ofthe system, the efficiencies can vary, which hasa negative effect on the energy demands andthe operating costs.What options are there for optimisation? Howcan one manage such problems and keep themunder control, both in planning and operation?Let's consider the circuit between the watercooler and the load points. The transport ofthe cooling water from the water cooler to the"users", such as the RLT devices, fan coils, coolingfans, etc. is done by circulating pumps.Here, the cold water is to be distributed accordingto utilisation by dimensioning the pipelines(cross-sections) and control valves. Fundamentally,when dimensioning, a minimum and maximumdimensioning value result, which dependson the investment and operating costs. Low investmentcosts often involve small cross-sectionsin the pipes and fittings with relativelysmall pump connections. This solution, however,brings about high pressure losses in the watersupply network, and the resulting high operatingcosts. Conversely, however, higher investmentcosts don't automatically mean lower operatingcosts!CapacitorsRefrigeratingmachinen=konst.VaporiserPrimary circuit(Generator part)6°C12 °CBased on the specific demands of the specifiedmodel system, it will be shown that, in practice,components are often planned for the hydraulicnetwork which aren't absolutely necessary.This often occurs due to ignorance and incorrectlyunderstood safety thinking. Also, this oftenresults in considerable and "avoidable" operatingcosts. The main task is to consider allcomponents with regard to their behaviour innormal operating situations and the costs theyinvolve. This is that much more important sinceall these costs make Germany a very highlypriced place to do business. The example can beapplied to every production, administration orresidential area. The physical and economicalpreconditions are identical. A basis for planningcooling water distributor systems will be presentedwhich will guarantee functionally safeand economic systems in the future.Secondary circuit(Load part)MMWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 83

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 84E CONOMICAL CONSIDERATION IN THE SELECTION OF FITTINGSMFittings Nominal k V valuediameterShut-off valve 50 80Three-way valve 40 50Non-return valve 45 50Separate machine cooling and room air coolingsystems were selected for economic reasons.For the machine part, 20200.00 kg/h of a water/glycol mixture are to be moved by the circulatingpump. The temperature is controlled by an admixingvalve and the loads adapted. Due to theflow volume, a pump with a connection size ofDN 50 is sufficient. The pipeline is chosen tohave a size of DN 100. In order to keep the buildingcosts down, the isolating valves required beforeand after the pump for maintenance reasonscould be selected to be size DN 50. A k V valueof 40 for the control valve is to be assumed fora valve authority of approx. 70 % for a very goodcontrol. This requires a pump with a deliverypressure of 91 kPa. For operation of approx.3800 hours per year and an electricity rate of€ 0.15, this makes € 604.00 in annual operatingcosts.Alternatively, the installation of shut-off valvesin size DN 100 is possible, with a control valvewith a k V value of 50 and a valve authority of approx.44 %. If a tightly closing valve is selected,the shut-off valve can be omitted. The requireddelivery pressure of the pump is then only 71 kPa.The annual operating costs are then only€ 457.00. This alternative over a time span of12 years means that € 1764.00 can be saved assumingenergy costs stay the same. For approx.€ 300.00 more in investment costs, which paysfor itself in less than 2 years in saved operatingcosts, there is a savings of € 147.00 for everyyear after that.MFittings Nominal k V valuediameterShut-off valve 100 800Three-way valve 100 50Non-return valve – –The other hydraulic circuits are to be consideredunder the same aspects. Usually, higher k V valuescan be selected for control valves and shutoffvalves at high control quality with the bigadvantage of lowered operating costs and amortisationin less than 2 years.The non-return valve is installed so that thereis no incorrect circulation. When tightly closingcontrol valves are used, this can be omitted.In order to prevent undesired circulation withinthe pipe due to gravitational effects, the sensiblepipe dimensioning should be given specialattention.84 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_32_85.QXP 25.05.2007 10:11 Uhr Seite 85E CONOMICAL CONSIDERATION IN THE SELECTION OF FITTINGSCommercially available flap traps must be operatedwith a differential pressure of over 10 kPa.Lower differential pressures mean that the flapswork at an unstable duty point, which results innoise and unstable operating states. In two-pipesystems with variable volume flows, the smallestflow is to be determined for stable operation.For this flow, a flap resistance of more than10 kPa is to be planned. For the full-load state,then, differential pressures of more than 50 kPaare only to be overcome for the flap trap of thecirculating pump. Additional operating costs arecreated which can add up to approx. € 130.00 to3643.00 per year depending on the efficiency ofthe pump at a flow rate of 1 to 70 m 3 /h. In thisexample, a shut-off valve or a ball valve with anactuator is recommended for the cooling waterside of the air-conditioning system for blockingthe two network pumps which automaticallyclose when the operation of the line isn't required.This results in approx. € 656.00 less inoperating costs per year.Hours of operation Σ [h/y]+10Savings potentialof the pump capacity+35Outdoor air temperature* [°C]100 %0 %Pump capacity [kW]-------Pump capacity for unreguatedpumps and directionchangingcircuit----Required pump capacity forregulated pumps and the useof throttling control*based on the city of Essen(NRW), GermanyWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 85

PLH_KKK_86_103.QXP 25.05.2007 10:24 Uhr Seite 86AppendixStandards(Translator's note: In this and the following twosections, the titles are free translations and notofficial titles.)DIN EN 1151-1Standard, 2006-11Pumps – Centrifugal pumps – Circulating pumpswith electric power consumption up to 200 Wfor heating systems and process water heatingsystems for domestic use – Part 1: Non-automaticcirculating pumps, requirements, testing,designation; German version EN 1151-1:2006DIN EN 13831Standard draft, 2007-02Expansion tanks with built-in membranefor installation in water systems;German version prEN 13831:2007ISO/TR17766Technical reportCentrifugal pumps for viscous fluids –Corrections of performance featuresDIN EN 1151-2Standard, 2006-11Pumps – Centrifugal pumps – Circulating pumpswith electric power consumption up to 200 Wfor heating systems and process water heatingsystems for domestic use – Part 2: Noise testingregulation (vibro-acoustical) for measuringstructure-borne noise and fluid-borne noise;German version EN 1151-2:2006DIN ISO 9905 Amendment 1Standard, 2006-11Centrifugal pumps – Technical requirements –Class I (ISO 9905:1994), amendments toDIN ISO 9905:1997-03; German versionEN ISO 9905:1997/AC:2006DIN ISO 10816-7Standard draft, 2007-03Mechanical vibrations – Assessment of machinevibrations by means of measurements on nonrotatingparts – Part 7: Centrifugal pumps forindustrial use (including measurement of shaftvibrations); ISO/DIS 10816-7:2006DIN V 4701-10 Supplement 1Preliminary standard, 2007-02Energetic assessment of heating and air-conditioningsystems – Part 10: Heating, potablewater heating, ventilation; Supplement 1:System ExamplesDIN EN 809Pumps and pump units for fluids – General safetyrequirements; German version EN 809:1998EN ISO 5198Rules for measuring the hydraulic operatingbehaviour – Precision class (ISO 5198:1987);German version EN 5198:1998EN ISO 9906Centrifugal pumps. Hydraulic acceptance test –Classes 1 and 2; (ISO 9906:1999); German versionEN ISO 9906:1999Fluid pumpsGeneral terms for pumps and pump systems,definitions, sizes, formula characters and units;German version EN 12723:2000DIN 24901: Graphic symbols for technical drawings– Fluid pumpsDINEN 22858: Centrifugal pumps with axial inletsDINEN 12262: Centrifugal pumps –Technical documentation – Terms, scope ofdelivery, design; German version EN 12262:1998DIN 24250: Centrifugal pumps - Naming andnumbering of components – Collection DINhome technologyDIN V 4701-10/A1Preliminary standard, 2006-12Energetic assessment of heating and air-conditioningsystems – Part 10: Heating, potablewater heating, ventilation;86 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_86_103.QXP 25.05.2007 10:24 Uhr Seite 87APPENDIXHandbooks2007, DIN paperback book 35Noise protection – Requirements, verifications,calculation methods and building-relatedacoustical tests2007, DIN paperback book 85Ventilation systems VOB (German constructioncontract procedures)/STLB - building -VOB Part B: DIN 1961, VOB Part C: ATV DIN 18299,ATV DIN 183792007, DIN paperback book 171Pipes, pipeline parts and pipe connections madeof reaction resin moulding materials2007, DIN paperback book 387Refrigerating technology 2 – Cooling devices,vehicle cooling2007, DIN paperback book 388Refrigerating technology 3 – Components,operating and auxiliary materialsVDI Handbook - Air-conditioning TechnologyVDI Handbook - Heating Technology2007, DIN paperback book 386Refrigerating technology 1 – Safety and environmentalprotection – Cooling systemsVDMA unit sheet24186-3 2002-09Range of products for maintaining technicalsystems and equipment in buildings - Part 3:Cooling devices and systems for the purposeof cooling and heating24186-5 2002-09Range of products for maintaining technicalsystems and equipment in buildings - Part 5:Electrical devices and systems1988-10CAD standard part file; Requirements for geometryand features; Drawing symbols, fluid pumps,compressors, fans, vacuum pumps24222 1998-05 Fluid pumps – Heating pumps –Data items for fieldbus systems24252 1991-04Centrifugal pumps with wear walls PN 10(wash-water pumps) with bearing brackets;Designation, nominal power, main dimensions24253 1971-02Centrifugal pumps with housing armour(armoured pumps); single-stream, single-stage,with axial inlet; Performance, main dimensions24261-1 1976-01Pumps; Naming according to way it works anddesign features; Centrifugal pumps24277 2003-07Fluid pumps – Installation – Low-tensionpipeline connection24278 2002-07Replacement for Issue 2000-04Centrifugal pumps – EDV size selection program –Specification document (with associated electronicversion of table B.1 "Field definitions"from Appendix B and an editor for making handlingeasier)24279 1993-04Centrifugal pumps; Technical requirements;Magnetic coupling and canned motor pumps24280 1980-11Displacement pumps; Terms, symbols, units24284 1973-10Testing of displacement pumps; General testingrules24292 1991-08Fluid pumps; Installation and operating instructionsfor pumps and pump units; Outline, checklist,text block - safety24901-5 1988-10Graphical symbols for technical drawings;Fluid pumps; Illustration in flow charts24261-3 1975-07Pumps; Naming according to way it works anddesign features; Rotating displacement pumpsWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 87

PLH_KKK_86_103.QXP 25.05.2007 10:24 Uhr Seite 88APPENDIXTables and guide valuesLoss coefficientRdBent elbows 15° 30° 45° 60° 90°Surface Surface Surface Surface Surfacesmooth rough smooth rough smooth rough smooth rough smooth roughζ for R = 0 0.07 0.10 0.14 0.20 0.25 0.35 0.50 0.70 1.15 1.30ζ for R = d 0.03 – 0.0 - – 0.14 0.34 0.19 0.46 0.21 0.51ζ for R = 2 d 0.03 – 0.06 – 0.09 0.19 0.12 0.26 0.14 0.30ζ for R 5 d 0.03 – 0.06 – 0.08 0.16 0.10 0.20 0.10 0.20Welded kneesNumber of circumferential weld seams– – – – 2 – 3 – 3 –ζ – – – – 0.15 – 0.20 – 0.25 –Qa/Q = 0.2 0.4 0.6 0.8 1ζ a = - 0.4 0.08 0.47 0.72 0.91Q dQζ d = - 0.17 0.30 0.41 0.51 –Q aQ dQ aQζ a = 0.88 0.89 0.95 1.10 1.28ζ d = -0.88 -0.05 0.07 0.21 –Q dQ aQ45°ζ a = -0.38 0 0.22 0.37 0.37ζ d = 0.17 0.19 0.09 -0.17 –Q45°Q dζ a = 0.68 0.50 0.38 0.35 0.48ζ d = -0.06 -0.04 0.07 0.20 –Q aThe ζ-value of the simple 90° elbow is not to bedoubled when putting several elbows togetheras follows, but is only to be multiplied by the respectivelyspecified factor in order to get theloss of the multiple elbow.1.4 1.6 1.888 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_86_103.QXP 25.05.2007 10:24 Uhr Seite 89APPENDIX45°Inlet edgesharp ζ = 0.53 3 for ∆ =75° 60° 45°broken ζ = 0.25 0.55 0.20 0.05 ζ = 0.6 0.7 0.8Form d/D 0.5 0.6 0.7 0.8 0.91 = 0.56 0.41 0.26 0.13 0.042 for = 8° = 0.07 0.05 0.03 0.02 0.01 = 15° = 0.15 0.11 0.07 0.03 0.01 = 20° = 0.23 0.17 0.11 0.05 0.023 = 4.80 2.01 0.88 0.34 0.114 for 20Γ 40Γ = 0.21 0.10 0.05 0.02 0.01ExtensionsForm 1d D ddDForm 2ReducersDdForm 3DdForm 4Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 89

PLH_KKK_86_103.QXP 25.05.2007 10:24 Uhr Seite 90APPENDIXLoss value with DNFittings [DN] 10 15 20 25 32 40 50 65 80 100 125 150 200 250 300 350 400Flat slide valve 0.65 0.6 0.55 0.5 0.5 0.45 0.4 0.35 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3Cocks [d E = DN] 0.15Shutters 1.5 0.65 0.4 0.3 0.5 0.6 0.2 0.2 0.2 0.3 0.3Flat-seat valve 6.0Angle-seat valve 2.6Free-flow valve 1.6Flap traps 3.0Foot valve 1.9 9.6 4.3 4.9 3.6 5.2 5.8 4.2 4.4 4.5 4.5 3.3 7.1 6.2 6.3 6.3 6.6Angle valve 3.1 3.1 3.1 3.1 3.4 3.8 4.1 4.4 4.7 5.0 5.3 5.7 6.0 6.2 6.3 6.3 6.6Expansion bend - 0.8bare pipeExpansion bend - 1.6folded pipeExpansion bend - 4.0corrugated pipeCorrugated pipe 0.3compensator withconducting pipeDefinition of viscosityAreaForceLayer thicknessSpeed differenceη =τ = Force =F NArea A [ m ] 2Speed difference dvγ . = = [ sLayer thickness dy-1 ]90 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_86_103.QXP 25.05.2007 10:24 Uhr Seite 91APPENDIXPipe frictional lossesPVC pipePipe friction resistance R [mm/m]300200150100705040304.0 m/s3.5 m/s3.0 m/s2.8 m/s2.6 m/s2015DN80DN1002.2 m/s2.0 m/s1.8 m/s1.6 m/s2.4 m/s10DN 10DN 15754321,50.2 m/s0.3 m/s0.4 m/sDN125DN1501.4 m/sDN 20DN 25DN 32DN 40DN 50DN 650.7 m/s0.6 m/s0.5 m/s1.2 m/s1.0 m/s0.9 m/s0.8 m/sDN200DN250DN300DN350DN40010.1 m/s0,1 0,2 0,3 0,5 1 2 3 5 10 20 30 50 100 200 400 600Flow rate Q [m³/h]Steel pipePipe friction resistance R [mm/m]300200150100705040302015107543/81/23/4111/4DN 401.0 m/s0.9 m/s0.8 m/s0.7 m/s0.6 m/s0.5 m/sDN 501.5 m/sDN 652.0 m/sDN 803.0 m/sDN 100DN 125DN 1504.0 m/sDN 2 005.0 m/s30.4 m/s21,50.15 m/s0.2 m/s0.3 m/s10,1 0,2 0,3 0,5 1 2 3 5 10 20 30 50 100 200 400 600Flow rate Q [m³/h]Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 91

PLH_KKK_86_103.QXP 25.05.2007 10:24 Uhr Seite 92APPENDIXEthylene glycol with 40% admixtureAntifrogen NFluid Density Kinematic Specific Relativetemperature viscosity heat capacity pressureloss[°C] ρ [kg/m 3 ] ν [mm 2 /s] c P [kJ/kg·K] f P-30 - - - --25 1080 26.73 3.43 2.313-20 1079 18.59 3.44 2.147-15 1078 13.63 3.45 1.999-10 1077 10.38 3.46 1.868-5 1076 8.14 3.47 1.7510 1074 6.52 3.48 1.6465 1072 5.33 3.49 1.55310 1070 4.42 3.5 1.47015 1068 3.72 3.51 1.39620 1066 3.16 3.53 1.33025 1064 2.72 3.54 1.27130 1062 2.36 3.55 1.21935 1059 2.07 3.56 1.17240 1057 1.82 3.57 1.12945 1054 1.62 3.59 1.09150 1051 1.45 3.6 1.05755 1048 1.31 3.61 1.02660 1045 1.19 3.63 0.99865 1042 1.09 3.64 0.97270 1039 1.00 3.66 0.94975 1036 0.93 3.67 0.92780 1032 0.86 3.68 0.90785 1029 0.80 3.7 0.88790 1025 0.76 3.71 0.86995 1022 0.71 3.73 0.851100 1018 0.68 3.74 0.834TyfocorDensity Kinematic Specific Relativeviscosity heat capacity pressurelossρ [kg/m 3 ] ν [mm 2 /s] c P [kJ/kg·K] f P- - - -1099 21.9 3.29 2.0121077 17.1 3.33 1.9131075 13.4 3.36 1.7991073 10.6 3.40 1.6891071 8.49 3.43 1.5881068 6.85 3.46 1.5001066 5.57 3.49 1.4381064 4.58 3.52 1.3751061 3.81 3.55 1.3131059 3.19 3.57 1.2631056 2.70 3.60 1.2251054 2.31 3.62 1.1751051 1.99 3.64 1.1381049 1.73 3.66 1.1001046 1.52 3.68 1.0751043 1.34 3.70 1.0501040 1.20 3.72 1.0251037 1.08 3.73 0.9981034 0.99 3.75 0.9751031 0.91 3.76 0.9501028 0.85 3.77 0.9251025 0.79 3.78 0.9631022 0.75 3.79 0.8881019 0.72 3.79 0.8751016 0.69 3.80 0.8501013 0.67 3.80 0.83892 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_86_103.QXP 25.05.2007 10:24 Uhr Seite 93APPENDIXEthylene glycol with 50% admixtureAntifrogen NFluid Density Kinematic Specific Relativetemperature viscosity heat capacity pressureloss[°C] ρ [kg/m 3 ] ν [mm 2 /s] c P [kJ/kg·K] f P-30 1101 71.54 3.17 2.886-25 1100 43.62 3.18 2.654-20 1099 29.13 3.20 2.45-15 1097 20.66 3.21 2.27-10 1095 15.32 3.23 2.110-5 1093 11.73 3.24 1.9690 1091 9.23 3.26 1.8445 1089 7.42 3.27 1.73310 1087 6.07 3.29 1.63415 1085 5.05 3.31 1.54720 1082 4.25 3.32 1.46925 1079 3.62 3.34 1.39930 1077 3.12 3.36 1.33835 1074 2.71 3.37 1.28240 1071 2.38 3.39 1.23345 1068 2.10 3.41 1.18850 1065 1.88 3.42 1.14955 1062 1.68 3.44 1.11260 1059 1.52 3.46 1.08065 1056 1.38 3.47 1.05070 1052 1.27 3.49 1.02375 1049 1.17 3.51 0.99780 1046 1.08 3.53 0.97385 1042 1.00 3.54 0.95190 1038 0.94 3.56 0.93095 1035 0.88 3.58 0.910100 1031 0.83 3.60 0.890TyfocorDensity Kinematic Specific Relativeviscosity heat capacity pressurelossρ [kg/m 3 ] ν [mm 2 /s] c P [kJ/kg·K] f P1099 54.20 2.95 2.4631096 37.00 2.99 2.2501094 26.20 3.03 2.0631091 19.20 3.07 1.9381088 14.40 3.11 1.8021086 11.20 3.14 1.7381083 8.84 3.18 1.6011081 7.13 3.21 1.5501078 5.85 3.25 1.4631075 4.88 3.28 1.4121072 4.11 3.31 1.3501070 3.51 3.34 1.3001067 3.02 3.37 1.2501064 2.63 3.40 1.2131061 2.30 3.42 1.1751058 2.03 3.45 1.1501055 1.81 3.47 1.1001052 1.62 3.50 1.7501048 1.45 3.52 1.5001045 1.32 3.54 1.0201042 1.20 3.56 1.0001038 1.10 3.58 0.9751035 1.01 3.59 0.9631031 0.93 3.61 0.9381027 0.87 3.62 0.9131024 0.81 3.63 0.8881020 0.76 3.65 0.875Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 93

PLH_KKK_86_103.QXP 25.05.2007 10:28 Uhr Seite 94APPENDIXPropylene glycol with 40% admixtureAntifrogen LFluid Density Kinematic Specific Relativetemperature viscosity heat capacity pressureloss[°C] ρ [kg/m 3 ] ν [mm 2 /s] c P [kJ/kg·K] f P-30 - - - --25 - - - --20 1056 44.42 3.62 2.660-15 1055 31.09 3.64 2.385-10 1053 22.25 3.65 2.163-5 1051 16.34 3.66 1.9830 1049 12.32 3.68 1.8375 1047 9.53 3.69 1.71610 1044 7.53 3.70 1.61515 1042 6.06 3.71 1.52920 1039 4.94 3.73 1.45425 1036 4.08 3.74 1.38630 1033 3.39 3.75 1.32435 1030 2.86 3.77 1.26640 1027 2.43 3.78 1.1145 1024 2.10 3.79 1.15950 1020 1.84 3.81 1.10955 1017 1.63 3.82 1.06160 1013 1.45 3.84 1.01765 1010 1.31 3.85 0.97770 1006 1.17 3.87 0.94175 1002 1.05 3.88 0.91080 998 0.95 3.89 0.88585 994 0.85 3.91 0.86590 991 0.77 3.92 0.84995 987 0.72 3.94 0.838100 983 0.68 3.95 0.829Tyfocor LDensity Kinematic Specific Relativeviscosity heat capacity pressurelossρ [kg/m 3 ] ν [mm 2 /s] c P [kJ/kg·K] f P- - - -- - - -1059 44.7 3.53 2.4051057 30.4 3.55 2.2331055 21.4 3.57 2.0331052 15.4 3.59 2.1701050 11.4 3.61 1.8051048 8.62 3.63 1.7171045 6.69 3.64 1.6001042 5.30 3.66 1.4671040 4.28 3.68 1.3501037 3.53 3.70 1.3001037 2.96 3.72 1.2331031 2.52 3.74 1.1831028 2.18 3.76 1.1501025 1.90 3.78 1.1001022 1.69 3.79 1.0671019 1.51 3.81 1.0331015 1.36 3.83 1.0171012 1.24 3.85 0.9831008 1.14 3.87 0.9501005 1.04 3.89 0.9331001 0.96 3.91 0.917997 0.89 3.92 0.900994 0.82 3.94 0.883990 0.72 3.96 0.867986 0.70 3.98 0.83394 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_86_103.QXP 25.05.2007 10:28 Uhr Seite 95APPENDIXPropylene glycol with 50% admixtureAntifrogen LFluid Density Kinematic Specific Relativetemperature viscosity heat capacity pressureloss[°C] ρ [kg/m 3 ] ν [mm 2 /s] c P [kJ/kg·K] f P-30 1072 202.20 3.37 3.958-25 1070 128.58 3.39 3.473-25 1070 128.58 3.39 3.473-15 1067 54.94 3.43 2.748-10 1065 37.78 3.44 2.480-5 1062 26.94 3.46 2.2610 1060 19.89 3.48 2.0815 1057 15.13 3.50 1.93210 1054 11.80 3.52 1.80715 1051 9.37 3.53 1.7020 1048 7.55 3.55 1.60825 1045 6.13 3.57 1.52630 1042 5.01 3.59 1.45135 1038 4.12 3.60 1.38340 1035 3.43 3.62 1.31945 1031 2.88 3.64 1.25850 1027 2.45 3.66 1.20155 1024 2.12 3.67 1.14760 1020 1.84 3.69 1.09865 1016 1.62 3.71 1.05270 1012 1.42 3.73 1.01175 1008 1.25 3.75 0.97580 1004 1.10 3.76 0.94485 1000 0.98 3.78 0.91990 996 0.87 3.80 0.9095 992 0.80 3.82 0.884100 988 0.75 3.85 0.872Tyfocor LDensity Kinematic Specific Relativeviscosity heat capacity pressurelossρ [kg/m 3 ] ν [mm 2 /s] c P [kJ/kg·K] f P1076 241 3.27 3.8001074 128 3.29 3.2001071 80.2 3.31 2.8001068 52.3 3.33 2.5331066 35.2 3.35 2.3171063 24.5 3.37 2.1001060 17.6 3.39 1.9331057 13.0 3.41 1.8001054 9.83 3.43 1.7001051 7.64 3.46 1.6001048 6.08 3.48 1.5001045 4.94 3.50 1.4171042 4.10 3.52 1.3501038 3.46 3.54 1.2831035 2.96 3.56 1.2331032 2.58 3.58 1.1831028 2.27 3.60 1.1501025 2.02 3.62 1.1171021 1.81 3.64 1.0671018 1.64 3.66 1.0331014 1.49 3.69 1.0171010 1.36 3.71 0.9831006 1.24 3.73 0.9671003 1.14 3.75 0.950999 1.04 3.77 0.917995 0.94 3.79 0.900991 0.85 3.81 0.883Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 95

PLH_KKK_86_103.QXP 25.05.2007 10:28 Uhr Seite 96APPENDIXVapor pressure and density of water at different temperaturesThis table shows the vapour pressure p [bar]and the density [kg/m 3 ] of water at differenttemperatures t [°C]. The table also shows theabsolute temperatures T [K].t [°C] T [K] p [bar] [kg/m 3 ] t [°C] T [K] p [bar] [kg/m 3 ] t [°C] T [K] p [bar] [kg/m 3 ]0 273.15 0.00611 999.8 138 411.15 3.414 927.61 274.15 0.00657 999.9 61 334.15 0.2086 982.6 140 413.15 3.614 925.82 275.15 0.00706 999.9 62 335.15 0.2184 982.1 145 418.15 4.155 921.43 276.15 0.00758 999.9 63 336.15 0.2286 981.6 150 423.15 4.760 916.84 277.15 0.00813 1000.0 64 337.15 0.2391 981.15 278.15 0.00872 1000.0 65 338.15 0.2501 980.5 155 428.15 5.433 912.16 279.15 0.00935 1000.0 66 339.15 0.2615 979.9 160 433.15 6.181 907.37 280.15 0.01001 999.9 67 340.15 0.2733 979.3 165 438.15 7.008 902.48 281.15 0.01072 999.9 68 341.15 0.2856 978.8 170 443.15 7.920 897.39 282.15 0.01147 999.8 69 342.15 0,.2984 978.2 175 448.15 8.924 892.110 283.15 0.01227 999.7 70 343.15 0.03116 977.7180 453.15 10.027 886.911 284.15 0.01312 999.7 71 344.15 0.03253 977.7 185 458.15 11.233 881.512 285.15 0.01401 999.6 72 345.15 0.03396 976.5 190 463.15 12.551 876.013 286.15 0.01497 999.4 73 346.15 0.03542 976.0 195 468.15 13.987 876.414 287.15 0.01597 999.3 74 347.15 0.03696 975.3 200 473.15 15.50 864.715 288.15 0.01704 999.2 75 348.15 0.03855 974.816 289.15 0.01817 999.0 76 349.15 0.04019 974.1 205 478.15 17.243 858.817 290.15 0.01936 998.8 77 350.15 0.04189 973.5 210 483.15 19.077 852.818 291.15 0.02062 998.7 78 351.15 0.04365 972.9 215 488.15 21.060 846.719 292.15 0.02196 999.5 79 352.15 0.04547 972.3 220 493.15 23.198 840.320 293.15 0.02397 998.3 80 353.15 0.04736 971.6 225 498.15 25.501 833.921 294.15 0.02485 998.1 81 354.15 0.4931 971.0 230 503.15 27.976 827.322 295.15 0.02642 997.8 82 355.15 0.5133 970.4 235 508.15 30.632 820.523 296.15 0.02808 997.6 83 356.15 0.5342 969.7 240 513.15 33.478 813.624 297.15 0.02982 997.4 84 357.15 0.5557 969.1 245 518.15 36.523 806.525 298.15 0.03166 997.1 85 358.15 0.5780 968.4 250 523.15 39.776 799.226 299.15 0.03360 996.8 86 359.15 0.6011 967.8 255 528.15 43.746 791.627 300.15 0.03564 996.6 87 360.15 0.6249 967.128 301.15 0.03778 996.3 88 361.15 0.6495 966.5 260 533.15 46.943 783.929 302.15 0.04004 996.0 89 362.15 0.6749 965.8 265 538.15 50.877 775.930 303.15 0.04241 995.7 90 363.15 0.7011 965.2 270 543.15 55.058 767.8275 548.15 59.496 759.331 304.15 0.04491 995.4 91 364.15 0.7281 964.4 280 553.15 64.202 750.532 305.15 0.04753 995.1 92 365.15 0.7561 963.833 306.15 0.05029 994.7 93 366.15 0.7849 963.0 285 558.15 69.186 741.534 307.15 0.05318 994.4 94 367.15 0.8146 962.4 290 563.15 74.461 732.135 308.15 0.05622 994.0 95 368.15 0.8453 961.6 295 568.15 80.037 722.336 309.15 0.05940 993.7 96 369.15 0.8769 961.0 300 573.15 85.927 712.237 310.15 0.06274 993.3 97 370.15 0.9094 960.2 305 578.15 92.144 701.738 311.15 0.06624 993.0 98 371.15 0.9430 359.6 310 583.15 98.700 690.639 312.15 0.06991 992.7 99 372.15 0.9776 958.640 313.15 0.07375 992.3 100 373.15 1.0133 958.1 315 588.15 105.61 679.196 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_86_103.QXP 25.05.2007 10:28 Uhr Seite 97APPENDIXt [°C] T [K] p [bar] [kg/m 3 ] t [°C] T [K] p [bar] [kg/m 3 ] t [°C] T [K] p [bar] [kg/m 3 ]41 314.15 0.07777 991.9 102 375.15 1.0878 956.7 320 593.15 112.89 666.942 315.15 0.09198 991.5 104 377.15 1.1668 955.2 325 598.15 120.56 646.143 316.15 0.08639 991.1 106 379.15 1.2507 953.7 330 603.15 128.63 640.444 317.15 0.09100 990.7 108 381.15 1.3390 952.2 340 613.15 146.05 610.245 318.15 0.09582 990.2 110 383.15 1.4327 950.746 319.15 0.10086 989.8 350 623.15 165.35 574.347 320.15 0.10612 989.4 112 385.15 1.5316 949.1 360 633.15 186.75 527.548 321.15 0.11162 988.9 114 387.15 1.6362 947.649 322.15 0.11736 988.4 116 389.15 1.7465 946.0 370 643.15 210.54 451.850 323.15 0.12335 988.0 118 391.15 1.8628 944.5 474.15 647.30 221.2 315.4120 393.15 1.9854 942.951 324.15 0.12961 987.652 325.15 0.13613 987.1 122 395.15 2.1145 941.253 326.15 0.14293 986.6 124 397.15 2.2504 939.654 327.15 0.15002 986.2 126 399.15 2.3933 937.955 328.15 0.15741 985.7 128 401.15 2.5435 936.256 329.15 0.16511 985.2 130 403.15 2.7013 934.657 330.15 0.17313 984.658 331.15 0.18147 984.2 132 405.15 2.8670 932.859 332.15 0.19016 983.7 134 407.15 3.041 931.160 333.15 0.19920 983.2 136 409.15 3.223 929.4Further ReadingPaperback book of Heating + Air-conditioningTechnology (Recknagel/Sprenger/Schramek),Oldenbourg-Industrieverlag, Essen 2006Centrifugal pump (Gülich), Springer-Verlag,Heidelberg 2004Paperback book of refrigerating technology(Pohlmann/Iket, Hrsg.), C.F. Müller-Verlag,Heidelberg 2005The cooling system engineer (Breidenbach),C.F. Müller-Verlag, Heidelberg 2003Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 97

PLH_KKK_86_103.QXP 25.05.2007 10:34 Uhr Seite 98SeminarsWilo seminarsThe Wilo seminars will help you always keep yourprofessional expertise up-to-date: with manytraining programs in the areas of heating, cooling,air conditioning, water supply as well assewage disposal.The seminars are specifically tailored to the requirementsof your daily work routine. Our trainershave many years of experience in skilled craftfirms and for this reason always teach seminarswith a direct reference to daily practice.The training centres in Dortmund and Oscherslebenoffer an optimal environment for modernlearning at the highest level. Besides conferenceand meeting rooms, they have practicallyequipped method rooms: ideal for the handlingorientedtraining on pumps and system models.Current information and dates forWilo seminars can be found at:www.wilo.comThe one-day events – including lunch – are freeof charge for you. You will get a Wilo certificateafter successfully participating in the seminar.Wilo-Brain80 to 90 % of all customer complaints withregard to heating and secondary hot watercirculation systems can be easily avoided:by designing/adjusting the system to be demand-oriented.Wilo-Brain will help you to make your customershappier and to make your business more successful.Hereby, this isn't a product training program,but a general system training programspanning many manufacturers. Wilo-Brain utilisesexisting knowledge, puts this in systematiccontext and offers brand new tips and tricks forinstallation and maintenance. Whether a hydraulicbalancing of heating systems of hygieneprotection in secondary hot water circulation:Wilo-Brain passes on expertise for noise-free,smooth system operation and long-term energyefficiency.The system training programs take place inWilo Brain Centres, industry-wide trainingcentres for guilds, chambers and technicalcolleges all over Germany.98 Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_86_103.QXP 25.05.2007 10:35 Uhr Seite 99Pumpenfibel2005Pumpen und Systeme fürGebäudetechnik, Industrie undkommunale Wasserversorgung und -entsorgungLieferprogramm – 50 Hz – 2007Planungshandbuch2007Planungshandbuch2007Planungssoftwarefür Pumpen,Pumpensystemeund KomponentenWindows98/ME/NT/2000/XPVersion 3.1.3 DEDeutschlandMärz 2005www.wilo.deselect@wilo.deInformation materialGrundlagen derPumpentechnikBasic knowledgeGesamtübersichtProduct cataloguesKälte-, Klima- undKühltechnikRegenwassernutzungstechnikWilo-Select ClassicPlanning informationOptimierung von HeizungsanlagenOptimierung von Trinkwarmwasser-ZirkulationsanlagenWilo-Brain ArbeitsmappeWilo-Brain ArbeitsmappeOptimierung von HeizungsanlagenWilo-Brain Tipps und TricksOptimierung von Trinkwarmwasser-ZirkulationsanlagenWilo-Brain Tipps und TricksSystem knowledgeThis information material canbe ordered with the orderforms on the following pagesor you can order online atwww.wilo.deWilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007 99

PLH_KKK_86_103.QXP 25.05.2007 10:42 Uhr Seite 100Pumpenfibel2005Pumpen und Systeme fürGebäudetechnik, Industrie undkommunale Wasserversorgung und -entsorgungLieferprogramm – 50 Hz – 2007Planungshandbuch2007Planungshandbuch2007Fax/letter response0 18 05 F•A•X•W•I•L•O*0 18 05 3•2•9•9•4•5•6*(master copy)WILO AGMarket ManagementNortkirchenstraße 10044263 DortmundCompany address/Billing addressGermanyPlease send me:Basic knowledgeWilo Pump ManualStamp/signatureGrundlagen derPumpentechnikMailing addresscopiesCompanyProduct cataloguesWilo-CompactSkilled craftsmen cataloguewith product and planninginformationNameStreet, no.copiesZIP code/ Town or cityGesamtübersichtComplete overviewPumps and systems for buildingengineering, industry andmunicipal water supply anddisposalTelephoneTelefaxcopiesE-mailPlanning GuidesSewage TechnologyInternetcopiesKälte-, Klima- undKühltechnikCooling/air conditioning andcooling technologyRegenwassernutzungstechnikcopiesRainwater utilisation technologycopies*14 cents per minute from the German fixed line networkPlanning guide for refrigeration, air-conditioning and cooling technology 02/2007Subject to change without prior notice 02/2007 WILO AG

PLH_KKK_86_103.QXP 25.05.2007 10:42 Uhr Seite 101Fax/letter response+49 7531 580185(master copy)Dr.-Ing. Paul Christiani GmbH & Co. KGTechnisches Institut für AusundWeiterbildungHermann-Hesse-Weg 278464 KonstanzCompany address/Billing addressStamp/signatureSystem knowledgeMailing addressOptimierung von HeizungsanlagenWilo-Brain ArbeitsmappeWilo-Brain WorkbookOptimisation of heatingsystemsOrder no.: 103936per book € 45.00 plus tax.CompanyNamecopiesStreet, no.ZIP code/ Town or cityOptimierung von Trinkwarmwasser-ZirkulationsanlagenWilo-Brain ArbeitsmappeWilo-Brain WorkbookOptimisation of hot drinkingwater circulation systemsOrder no.: 71329per book € 45.00 plus tax.copiesTelephoneTelefaxE-mailInternetPlanning guide for refrigeration, air-conditioning and cooling technology 02/2007Wilo Planning Guide - Refrigeration, air-conditioning and cooling technology 02/2007

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PLH_KKK_86_103.QXP 25.05.2007 10:42 Uhr Seite 103WILO AG has worked on the text in this document with great care. Still, errors cannot be ruled out.Publisher liability is excluded, regardless of the legal ground.Editorial staff members:Manfred Oraschewski, Joachim Scheiner, Stephan Thomas SchusterCopyright 2007 by WILO AG, DortmundThis work, including all its parts, is copyright protected. Any use outside the narrow limits ofcopyright law is illegal and liable to prosecution without the permission of WILO AG. This especiallyapplies for duplications, translation, microfilms, other types of processing, as well as for thestoring and processing in electronic systems. This also applies for taking individual figures andusing excerpts from text.1st Edition 2007

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