Download - GSR Ventiltechnik

2008Flange valves: one modularsystem for all applicationsJasmin Müller and Dirk KlinksiekGSR Ventiltechnik GmbH & Co. KG, Vlotho/Germanypublished in Industrial Valves, International Edition of Industriearmaturen 2008Vulkan-Verlag GmbH, Essen, GermanyContact: W. Mönning, Tel. +49 201 82002-25, w.moenning@vulkan-verlag.de

REPORTSFlange valves: one modularsystem for all applicationsJasmin MüllerThe extremely wide application spectrum for flange valves ranges from MEMS and fluid technologyto multiple aspects of processing technology and power engineering. This article describes amodular system, which was developed by GSR – a leading manufacturer of flange valves – in orderto enable an optimal adjustment of the valves to the individual application.SAs the valves are increasingly used indemanding and sometimes even criticalfields of application, they offer a highdegree of safety. The force pilot operatedsolenoid valves as from nominal sizeDN 32 for instance are as a standardequipped with an adjustable closedampening, in order to avoid waterhammer effects when the valve is clostandardproduct or individual design?Mechanical engineers are oftenconfronted with this question, whenthey need components for demandingmachinery and plants. When theychoose a standard product, they knowfor sure that the cost outline will befavourable, but on the other hand, theyhave to accept that the componentdoes not accurately meet the requirements.If they prefer using an individuallydesigned product, they will have toaccept that the engineering costs willbe high – as will be the costs – and nostatements or claims can be made asavailability and process safety are regarded,since they cannot revert to previousexperiences with this component.tions as well as saltwater-resistant versionsare included as well.Arbitrary control typeThe basics of the modular system arevalve series with piston, diaphragmand poppet seals which are availablefor different pressure ranges. Hereby,nominal sizes from DN 15 to DN 300and maximum pressures from 16 to160 bar are achieved. These designscan be combined with different controltypes; the modular programme includesdirect acting valves, pilot operatedvalves and force pilot operated valveswith manual, electrical and pneumaticoperation. The casings are made ofbrass, stainless steel or GG-25 or GS-C25 and of course, different sealingmaterials such as NBR, EPDM, FKMand PTFE are offered as well.High safety levelThe best of both worldsBoth methods have their advantagesand disadvantages. GSR Ventiltechnikhas developed a product concept(Figure 1), which offers the user the“best of both worlds”: a modular systemfor flange valves enabling the configurationof valves for demanding applications.As the system has grown through theyears, this modular design from GSRmeanwhile also covers rather “exotic”applications. The spectrum originallywas limited to rather small nominalwidths and applications for the conventionalfluid technology, but nowadaysversions for special fields, e.g. hightemperatureand high-pressure applica-Fig. 1: Overview of flange valves, different control types18Industrial Valves 2008

REPORTSing. For higher pressures (25 to 150bar), the diaphragm of the pilot operatedvalves is replaced with a robust pistonas sealing element. These constructivedetails create the perfect conditionsfor a reliable operation of the valve duringan extremely long time.Large options programmeThis programme, by means of whichsome 40 different series can be generated,covers the needs of many fields ofapplications, from filling systems, brewingequipment and chemical plants torefineries, power plant technology, watertreatment and drinking-water supply.The application possibilities can be furtherextended by means of the numerousavailable options.These options include, for instance, positionindicators with different detectionprinciples (capacitive, inductive orReed contacts) for monitoring the valveposition. If one position indicator isused, the “off” position will be displayed;if two position indicators areused, both the “on” and “off” positionwill be displayed.As the electrical connection is regarded,variants for all common AC andDC circuits from 12 to 240 V with cableconnection or terminal box wiringare available. And if the user cannotFig. 2: Flange valve with oil brakefind anything in the line of his application,a connection for special voltagescan be supplied. Further options include,amongst other things, NPTthreads, casings free of oil and greaseas well as in nonferrous heavy metaland versions with a special surfacetreatment for open-air assembly.Option for burner controlsystems: the hydraulic brakeSome of these options are intended forvery specific applications, for instancethe so-called hydraulic or oil brake(Figure 2). This additional module is especiallyused for valves regulating thegas supply on large gas furnaces,which are usually installed on the continuoushardening furnaces in the steelindustry. Here, the hydraulic brake ensuresthat the flame is not smothered orextinguished by the inflow of gas. Thehydraulic brake thus enables a failurefreeoperation of the furnace and simultaneouslyserves as safety equipment.The essential component of the hydraulicbrake is a pneumatically controlledpilot valve, which is connectedto the control system of the plant. Thevalve opens slowly and interrupts theflow within 0.5 seconds in case of danger.This simple yet efficient option iscertified for this kind of applicationsand can be used for valves with nominalsizes of up to DN 150.Integration in automatic controlsystemsThe options programme of the modularflange valve system also includes a regulator.This module enables the integrationof the valve in automatic controlsystems, where it can be used for theflow rate regulation, e.g. in mixing anddosing processes. The regulator has acontrol system equipped with an actualvalue generator, which queries the spindleposition, and a monitoring moduleto synchronise the actual and the targetvalue. The connection to the control systemof the plant is realised through standardinterfaces and the module has anaccuracy of approximately 5 %. In caseof a failure of the control system, thevalve autonomously closes and remainsin zero position, thus contributing to theprocess safety as well.Series for high-temperatureapplicationsHigh-quality valves are often used totransport hot media or need to operatein high ambient temperatures, for instancein power plant technology, steelprocessing, surface hardening technologyor steam generators. For such applications,GSR has extended theflange valve system with multiple forcepilot operated, direct acting and directpressure controlled versions, which canbe used for temperatures of up to 250,300, 350 and 400 °C.Comprehensive programme forexplosion protectionExplosion risks are not a “monopoly” ofthe chemical industry. In power generatorsfor instance, inflammable gases areused as well. For handling this kind ofmedia, the valve system includes acomprehensive programme of flangevalves for the gas-Ex zones 1 and 2.GSR has a thorough know how in thissafety-critical field, which is permanentlyextended. GSR also manufacturessaltwater-resistant Ex valves for offshoreplants.Gas and hydrogen handling:a growing marketEx supply valves for CNG filling stationsare an important and growingFig. 3: Valve for CNG filling stationsIndustrial Valves 2008 19

REPORTSmarket. GSR valves are used in naturalgas distribution networks as well(Figure 3 and 4). These applications requirevalves equipped with large valveseats and a robust design, which aresuitable for pressures up to 350 barand feature a long life even underrough ambient conditions. For this demandingbusiness, GSR supplies thevalve technology for the entire processchain from compressor to gas pump.Development project:hydrogen valves for fuel cellsThe GSR engineers are currently dealingwith the energy source of the future:when hydrogen is used to drive fuelcells or direct injection engines, specialvalves are needed, resisting to pressuresup to 900 bar (Figure 5). Thesevalves however cannot be assembledwith the standard components of themodular valve system, as such highFig. 4: Multiport valve for CNG stationspressures require a special casing.Some of the options however still canbe used.Also suitable for nicheapplicationsThis overview and the quoted applicationexamples prove that the flangevalve system from GSR covers a verylarge field of applications. Even forniche applications, “custom-made”valves can be configured at reasonableengineering costs. To this end, competentapplication-specific technical adviceas well as a highly flexible productionprocess is required in addition tothe modular valve system.High degree of verticalintegration, flexible productionThe manufacturer of a comprehensiveproduct range with many options musthave a flexible production process.GSR meets this requirement: even forbatch size 1, an economic productionis guaranteed and due to the high degreeof vertical integration, the deliverytimes are short. The single-part productionhowever is not often deployed, asthe individual valve is configured on thebasis of the modular system. In suchcase, the individual work often is limitedto “just” the assembly. This also offersthe advantage that spare parts arequickly at hand, even after long uptimes.GSR frequently supplies spareand wear parts from stock for valves,which have been manufactured some15 years ago and which are still operationaltoday without noteworthy failures.The prerequisites:advice and consultancyThe GSR technicians provide their customerswith detailed information andadvice, so that they can select the optimalvalve from the modular system. For,the media to be transported, the appliedprocesses and the boundary conditionsas well as the applicable safetyprescriptions and certifications play animportant part in making the rightchoice. GSR provides its customersworldwide with competent consultancy.The Chinese market for instance is animportant export market to GSR notwithstandingthe fierce competition of localcompanies. Here, the customers areadvised by engineers, who have beentrained in Germany. GSR furthermore isonly active in the upper quality segment,which is an additional advantagecompared to the competition:many international machinery and plantbuilders, who consider safety, long lifetime,long maintenance intervals andhigh availability of spare parts of paramountimportance, frequently use thevalve technology from GSR.Fig. 5:RRV ® Rapid ReactionValve resistingto pressures up to900 barJasmin MüllerGSR VentiltechnikGmbH & Co. KG,VlothoTel.: +49 5228 779 356jmueller@ventiltechnik.de20Industrial Valves 2008