ARCAPRO® positioner - Von Rohr ARCA BV

ARCAPRO ®positioner

ARCAPRO ®positionerPositionercustomized for specific tasks231A linear function between the input signal and stroke is thebest way to ensure maximum control precision. Controlvalves with pneumatic actuators, however, are subject tofriction, media pressure, and high flow forces, whichmeans that this linearity is not intrinsic in the system. Onlya positioner can eliminate positioning errors. To do so, itcompares the input signal (reference variable w) with theactual stroke (control variable x). Depending on the controldeviation (x W), the positioner uses the intake air pressure(p Z) to yield the actuating pressure (p S) for the actuator(actuating variable y). Either 0.2…1 bar, 4…20 mA ordigital signals can be used as input signals.1 Positioner mounting to IEC 534 (NAMUR)The standard mounting method to IEC 534 is based onmanufacturer-neutral mechanical interfaces with the actuatoryoke and stem. A bracket is normally used to securethe positioner, while the feedback lever comprises a leverwith a spring element. The inlet air is connected to thepositioner, while the pneumatic connection with the actuatoris realized by means of a pipe or hose.2 Direct integrated mountingThe positioner can be easily mounted on the actuator yokeby means of two screws to ensure that it is robust andprotected against vibrations. The feedback lever is locatedwithin the yoke, which offers better protection than theNAMUR mounting method. The actuating pressure is channeledfrom the positioner through the actuator yoke to theactuator without the need for additional piping, therebypreventing any leakage. The inlet air is connected directlyto the positioner.3 Integrated mounting to VDI/VDE 3847As with the NAMUR mounting method, this method usesstandardized mechanical interfaces with the actuator yokeand stem. The actuator interface, however, is also a pneumaticinterface, which means that, as with the directmounting method, the actuating pressure is channeled tothe actuator through the actuator yoke. In addition, the rearof the yoke is equipped with an interface for a solenoidvalve, which is pneumatically connected between the positionerand actuator, thereby enabling a safety shutdown ofthe unit. The inlet air is connected directly to the yoke,which means that no work needs to be carried out on thepiping if the positioner is replaced.244 ARCAPLUG ® stroke pick-upThe patented ARCAPLUG ® stroke pick-up connects thevalve stem and the stroke scanning lever. The taperedroller, which is made of wear-resistant plastic, gripsbetween two pins on the stem. The spring mechanism forthe tapered roller is self-adjusting, which means that thestroke is always detected without any zero backlash andwithout hysteresis. Even strong vibrations or heavyimpacts do not cause any wear and tear, and the spacingtolerances of the pins are optimal equalized.

The classic design:analog positioner type 824ARCAPRO ® positionerFunctional principlePositioner type 824 functions accordingto the tried-and-tested forcebalanceprinciple. The pneumatic setpointstandardized signal issued by apneumatic controller or I/p convertermodule generates a force on thediaphragm that is balanced with thespring force on the feedback shaft.The resulting difference in forcemoves the gate valve, which connectsthe actuator with the intake airor atmosphere, thereby controllingthe movement of the valve.Modular designPneumatic positioner type 824 ismodular in design and can be expandedwith a range of additionalmodules, thereby allowing it to beeasily customized for specific tasks.I/p converter moduleThe I/p converter module convertselectrical 0/4...20 mA input signalsto pneumatic standardized signalswith 0.2...1 bar for controlling thepositioner.Limit switch moduleTwo adjustable inductive switchesenable checkback signals for limitpositions to be sent to the controlsystem (e. g. as NAMUR signal).Feedback potentiometerThe feedback potentiometer generatesa message containing the actualposition for evaluation in the controlsystem.The intelligent design:ARCAPRO ® digital positioner type 827AFunctional principleARCAPRO ® is an intelligent, secondgenerationpositioner. It not onlyoffers a wider range of functions andhigher level of reliability, but also featuresan advanced online diagnosticssystem and optional maintenance display.The position of the stem is sentto a potentiometer whose outputsignal is then compared with the setpointby the microprocessor. Using aspecial control algorithm, the controlleractivates the two piezo valves,which connect the actuator with theinlet air or atmosphere.The ARCAPRO ® positioner can beoperated locally or from the controlroom.Optimized operating modesThe ARCAPRO ® positioner supportsthe following operating modes:■ Automatic or manual mode■ Initialization■ Parameterization■ DiagnosticsModular designThe ARCAPRO ® positioner is compactand modular.Additional modules increase yourrange of options:■ Analog module: Position transmitterfor signaling the actual positionas a current signal of 4...20 mA■ Binary module: Two adjustablesoftware limit switches, fault signalingswitch, binary input■ Slot initiator module: Two variableinductive limit switches, faultsignaling switch■ Contact module: Two adjustablemechanical limit switchesAutomatic commissioningThe automatic initialization functionallows you to commission the positionerquickly and easily. The parameterscan be set on the device or bymeans of HART, PROFIBUS or FoundationFieldbus communication. Thefollowing parameters can be set:■ Setpoint direction, characteristic■ Split-range mode■ Tight closing function■ Function for position and faultsignaling outputs and the binaryinputs3

Additional modulesincrease your range of optionsARCAPRO ® positionerPosition transmitterThe position transmitter comprises thefeedback potentiometer and an R/Iconverter. It is used for signaling theactual position as a 0/4...20 mA signal.Gauge groupThe gauge group displays the inletair pressure, setpoint air pressureand actuating pressure. It also allowsyou to check whether or not the positioneris functioning properly.Explosion-protected designs(for type 827A too)■ Intrinsically safe (EEx ia and EEx ia/ib)■ Explosion-proof (EEx d)■ Non-sparking (EEx n)I/p module 0/4–20 mALimit switch modulePositioner type 824Position transmitter0/4–20 mAModule coverCommunicationDepending on the version, theARCAPRO ® positioner enables communicationwith other field devices orprocess control systems via:■ HART■ PROFIBUS PA■ Foundation FieldbusAdvanced online diagnosticsto NE 91The advanced online diagnosticsfunction allows you to evaluate thestatus of the positioner. The diagnosticsvalues can be displayed locallyor queried via the communicationscable. A range of additional functionsthat enable even more accuratestatus analyses are also available:■ Partial stroke test■ Leak measurement■ Limit temperature monitoring■ Mean position value calculationMaintenance data to NE 107Three-stage limit value signaling toNE 107 can be carried out for theparameters acquired by means of theadvanced online diagnostics function.Slot initiator module(alternative)Contact module(alternative)Analog module (alternative)Filter moduleTo enable this, the relevant limit valuesthat trigger the signals must bedefined for the following statuses:■ Medium-term need for maintenance■ Urgent need for maintenance■ FailureMain electronicboardBinary module (alternative)The data is displayed on the deviceand can be sent to higher-level systemsvia the binary outputs or viaHART or bus communication. Thedata is normally evaluated in theprocess control system.4

Analog and digital –precision through innovationARCAPRO ®positionerSince 1917 when it released its patented nozzle-flappersystem, ARCA has been at the forefront of the industry forcontrol valves with positioners. Our advances over theyears have helped make modern positioner technologywhat it is today – and our state-of-the-art digital positionerARCAPRO ® is just the latest in a long line of innovations.Thanks to automatic adjustment in line with the controlvalve and user-friendly parameterization (e. g. direction ofaction, split range or stroke limitation), the system is easyto commission and operate. In addition, a range of variablediagnostics parameters allow preventive maintenancemeasures to be specially planned to avoid plant downtime.Modern communication options (e. g. HART, PROFIBUS,or Foundation Fieldbus) enable function and diagnosisparameters to be sent to process control systems forevaluation.1234567Our innovationClassic or intelligent digital positionerstried-and-tested over many yearsModular, retrofittable accessoryand option modulesIntegrated, pipe-free mountingPatented ARCAPLUG feedback leverMinimal air consumptionUniversal communicationAdvanced online diagnosticsHow you benefit■✔Long service life■✔Low lifecycle costs■✔Optimal adaptionto specific applications andcontrol systems■✔Compact design■✔High mechanical resistance■✔No sensitive piping■✔Self-adjusting■✔No hysteresis■✔Minimal wear and tear■✔Low operating costs■✔Easy adjustment in line with existingplant communication systems■✔All diagnostics data can be read on thedevice or in the control room■✔Self-monitoring of the complete valve■✔Precise planning of maintenancemeasureswww.arca-valve.com5

ARCAPRO ®positionerPositioner type 824General data Enclosure material Anodized aluminum / Glass-fiber-reinforced polyesterTemperature range –40…+80 °CSteady-state deviation < 0,5 %Linearity error < 2 %Hysteresis < 0,7 %Explosion protectionwithout / intrinsically safe / explosion-proofInput signal0,2…1 bar or 0/4…20 mA 2 wire connectionOption modules Position transmitter 4…20 mA, passive, 2/3 wire connection (not explosion proof)Limit switch2 NAMUR sensorsPneumatic data Inlet air pressure 1.4…6 barContinuous air consumption < 500 Ndm 3 /hMounting Linear actuators ARCA-integrated or to IEC 534; range of stroke 10…120 mmQuarter turn actuators To VDI/VDE 3845; angle of rotation 90°ARCAPRO ® positioner type 827AGeneral data Enclosure material Anodized aluminum, stainless steel, polycarbonateExplosion protectionTemperature range –30…+80 °CSteady-state deviation Typically < 0,3 %Linearity error Typically < 0,5 %Dead zone Self-adjusting (typically 0.3 %) or adjustable (0.1 % to 10 %)without / intrinsically safe / non-sparking / explosion-proofCommunication / input signal Standard / HART 4…20 mA 2 wire connection, 0/4…20 mA 3/4 wire connectionProfibus PA Profibus PA, profile B, version 3.0Foundation FieldbusH1 communicationBinary inputsSwitching or voltage inputs,parameterizable (e. g. «Move valve to CLOSED»)Option modules Analog module 4…20 mA position transmitter, passiveBinary moduleSlot initiator moduleContact modulePneumatic data Inlet air pressure 1.4…7 barContinuous air consumption < 36 Ndm 3 /h2 NAMUR limit switches, 1 NAMUR fault switch, 1 binary input2 inductive NAMUR limit switches, 1 NAMUR fault switch2 mechanical limit switchesMounting Linear actuators ARCA-integrated, integrated to VDI/VDE 3847 or to IEC 534;range of stroke 3…130 mmQuarter turn actuators Integrated to VDI/VDE 3847 or VDI/VDE 3845;angle of rotation 30…100°3049559 00 10.11.1 · Subject to change without noticeARCA Regler GmbHKempener Str.18, D-47918 TönisvorstPhone +49 (0)2156-7709-0, Fax +49 (0)2156 7709-55www.arca-valve.com, sale@arca-valve.comARCA Flow Group worldwide: Competence in valves, pumps & cryogenicsvon RohrArmaturen AGvon RohrARCA BV