Fisher 3710 and 3720 Positioners and 3722 Electro ...

1 3710 and 3720 positioners and 3722 Electro -Pneumatic ConverterFisher 3710 pneumatic and 3720 Electro -pneumaticpositioners are part of the 3700 positioner series. Theyare designed for use with either diaphragm or pistonrotary actuators. These Positioners provide a valve ballor disk position for a specific input signal. The 3710provides a valve position in response to a pneumaticinput signal. The 3720 is created by the addition of aFisher 3722 Electro -pneumatic converter to the 3710positioner. The positioner provides a valve position inresponse to a DC current input signal. Either type caneasily be configured as single- or double- acting forrotary POSITIONERMOUNTED ON A 1066 ACTUATORW6058-1 SUPPLYCONNECTION3720 POSITIONERMOUNTED ON A 1052 ACTUATORW6144W61451/2 NPT OR M20 CONDUIT CONNECTIONSUPPLYCONNECTIONEXTERNALGROUND INGSCREW3722 Electro -PNEUMATIC CONVERTER3710 and 3720 PositionersD200437X012 Product :3710 August 20183710 and 3720 PositionersD200437X012 Product :3710 August 2018 2 SpecificationsAvailable ConfigurationThe Fisher 3700 series of Positioners include thefollowing models:3710: JSingle- or Jdouble-acting pneumatic rotaryvalve positioner3720: JSingle- or Jdouble-actingelectro-pneumatic rotary valve positioner consistingof a 3710 with a 3722 attached3722: An Electro -pneumatic converter that convertsa 4-20 mA DC input signal to a to bar (3 to 15 psig) signal for the pneumatic positionerInput Signal3710.

2 Standard: to bar (3 to 15 psig) or J bar (6 to 30 psig)Split-Range: to bar (3 to 9 psig) and bar (9 to 15 psig) or to bar (6 to 18 psig)and to bar (18 to 30 psig)3720:.Standard: J4-20 mA DC constant current with 30 VDC maximum compliance voltageSplit-Range: J4-12 mA DC or 12-20 mA DCEquivalent Circuit3720: 120 ohms shunted by three V zener diodesOutput SignalPneumatic pressure as required by the actuator up tofull supply pressureAction(1): Field reversible between direct and reverseSupply Pressure(2)Minimum Recommended: bar (5 psig) aboveactuator requirementMaximum: bar (150 psig) or maximum pressurerating of the actuator, whichever is lowerSupply Medium3710: Air or Natural Gas3720: AirThe 3720 positioner is not approved for use withNatural Gas as the supply mediumSteady-State Air Consumption(3)3710:6 mm Spool Valve: normal m3/hr (29 scfh) at bar (60 psig) supply pressure3720:.6mm Spool Valve: normal m3/hr (36 scfh) at bar (60 psig) supply pressureMaximum Supply Air Demand(3) (Double-Acting)6 mm Spool Valve: 20 normal m3/hr (700 scfh) bar (60 psig) supply pressureTypical Performance(4)3710 Pneumatic PositionerIndependent Linearity: of output spanHysteresis: of output spanDeadband: of input span3720 Electro -Pneumatic PositionerIndependent Linearity: of output spanHysteresis: of output spanDeadband: of input spanElectromagnetic Compatibility for 3722electro-pneumatic converter: Meets EN 61326-1:2013 Immunity Industrial locations per Table 2 of the EN 61326-1 standard.

3 Performance is shown in table 1 below. Emissions Class A ISM equipment rating: Group 1, Class ANote: Electromagnetic Compatibility specificationsalso apply to the 3720 positionerOperating InfluencesSupply Pressure Sensitivity: A 10% change in supplypressure changes the valve shaft position less thanthe following percentages of valve rotation:3710: at bar (60 psig) supply pressure3720: at bar (60 psig) supply pressureOperative Temperature Limits(2)J-40 to 80_C (-40 to 180_F),J-50 to 107_C (-58 to 225_F)Construction MaterialsPositioner Base: Low copper aluminum alloyCover: Polyester plasticFeedback Shaft: Stainless steelRange Spring: Stainless steelInput Module Diaphragm, O-rings: JNitrile orJEthylene-propylene (EPDM)Spool Valve: SST/C72900 Tubing: Copper (standard)-continued-3710 and 3720 PositionersD200437X012 Product :3710 August 2018 3 Specifications (Continued)Construction Materials (continued)Fittings: Brass (standard)Gauges: Chrome-plated brass connection with plasticcase Connectors for diagnostic testing: JStainless steel orJBrassElectrical Classifications for 3722 ConverterCSA Intrinsically Safe, Explosion-proof, Type n,Dust-Ignition ProofFM Intrinsically Safe, Explosion-proof, Type n,Non-incendive, Dust-Ignition ProofATEX Intrinsically Safe, Flameproof, Type nIECEx Intrinsically Safe, Flameproof, Type nNote: These classifications also apply to the 3720positionerHousing Classification for 3722 ConverterCSA Type 3 IP64FM NEMA 3, IP54 IECEx IP54 Mount instrument with vent on side or bottom ifweatherproofing is a concernNote.

4 These classifications also apply to the 3720positionerOther Classifications/Certifications for 3722 ConverterCUTR Customs Union Technical Regulations (Russia,Kazakhstan, Belarus, and Armenia)INMETRO National Institute of Metrology, Qualityand Technology (Brazil)KGS Korea Gas Safety Corporation (South Korea)Contact your Emerson sales office or Local BusinessPartner for classification/certification specificinformationNote: This classification also applies to the 3720positionerHazardous Area Classification for 3710 PositionerComplies with the requirements of ATEX Group IICategory 2 Gas and DustMeets Customs Union technical regulation TP TC012/2011 for Groups II/III Category 2 equipmentII Gb c T*XIII Db c T*XNote: These ratings do not apply to the 3720positionerPressure Connections1/4 NPT internalElectrical Connection for 3720 Positioner1/2-14 NPT conduit connectionRotary Valve RotationJ90 degrees (standard) J60 degrees (optional)OptionsSpan Adjuster Assembly: to bar (3 to 15psig) input range or, to bar (6 to 30 psig)input rangeElastomers (O-rings, diaphragm): Jstandardtemperature range, -40 to 80_C (-40 to 180_F),Jextended temperature range -50 to 107_C (-58 to225_F)JSpecial applications, JBeacon indicator,JGauges(5), tire valves, or connectors for diagnostictestingApproximate Weight3710: kg ( pounds)3720: kg ( pounds)NOTE: Specialized instrument terms are defined in ANSI/ISA Standard - Process Instrument Direct-acting, an increasing input signal extends actuator rod.

5 Reverse-acting, an increasing input signal retracts actuator The pressure and temperature limits in this document and any applicable standard or code limitation should not be Normal m3/hr--Normal cubic meters per hour (0_C and bar, absolute); Scfh--Standard cubic feet per hour (60_F and psia).4. Typical values determined by tests with a 1061 size 30 actuator at bar (60 psig) supply pressure. Performance may vary with other actuator types and supply Gauges not available for high temperature and 3720 PositionersD200437X012 Product :3710 August 2018 4 Table 1. Fisher 3722 Electro -Pneumatic Converter(1) EMC Summary Results ImmunityPortPhenomenonBasic StandardTest LevelPerformanceCriteria(2)EnclosureElec trostatic Discharge (ESD)IEC 61000-4-24 kV contact;8 kV airARadiated EM fieldIEC 61000-4-380 to 1000 MHz @ 10V/m with 1 kHz AM at 80%1400 to 2000 MHz @ 3V/m with 1 kHz AM at 80%2000 to 2700 MHz @ 1V/m with 1 kHz AM at 80%ARated power frequency magneticfieldIEC 61000-4-860 A/m at 50 HzAI/O signal/controlBurst (fast transients)IEC 61000-4-41 kVASurgeIEC 61000-4-51 kV (line to ground only)BConducted RFIEC 61000-4-6150 kHz to 80 MHz at 3 voltsASpecification limit = 1% of span1.

6 The information contained in the table also applies to the 3720 A = No degradation during testing. B = Temporary degradation during testing, but is and 3720 PositionersD200437X012 Product :3710 August 2018 5 Featuresn Accurate, Fast Response 3710 and 3720positioners use field-proven spool valve technologyfor a simple design that gives accurate,fast-responding operation with high cycle Positioners are able to withstand the severevibrations of most plant Modular Construction The 3710 positionerconverts easily to a 3720 positioner by adding the3722 Electro -pneumatic converter. The convertermounts over the instrument and supply ports in the3710 positioner base. This provides a simple,compact, and cost-effective field conversion frompneumatic to Electro -pneumatic valve Corrosion-Resistant Construction with AirPurge Case, components, and gasket materialswithstand harsh environments. Proven engineeredresins and 300 Series stainless steel construction isused throughout each unit.

7 Die castings are lowcopper aluminum alloy to maximize corrosionresistance. positioner bleed air purges internalpositioner parts. As an option with some Fisheractuators, bleed air also purges the actuatorhousing for additional Extended Temperature Capability With EPDMO-rings and input module diaphragm, 3710 and3720 Positioners can be used in low-temperatureand high-temperature Meets Special Application Requirements 3710 and3720 Positioners with EPDM O-rings and inputmodule diaphragm can be used in applications withspecial material requirements as in the food andbeverage industry, pharmaceuticals, and Easy positioner Adjustments With the coverremoved (figure 1), all internal components areeasily accessed. Zero and span adjustments aremade by hand with no tools Stable Operation Changes in supply pressure andambient temperature have minimal effect onpositioner Control Valve Diagnostic Testing Capability Tosupport diagnostic testing ofvalve/actuator/ positioner packages, connectors,piping, and other hardware can be installedbetween the 3710 positioner and the actuator.

8 Atypical connector installation is shown in figure Valve Position Indicator Standard, low-profileindicator or optional, beacon-style indicator mounteasily to the positioner and 3720 PositionersD200437X012 Product :3710 August 2018 6 Figure 1. Features and AdjustmentsSPOOL VALVEINPUT MODULESUMMINGBEAMMOUNTINGSCREW HOLECAMMOUNTINGSCREW HOLEFEEDBACKARM ASSEMBLYZERO ADJUSTERZERO ADJUSTERLOCK NUTSPAN ADJ SHAFT(THREADED ROD)ZERO ADJ PIVOTSCREENEDVENTOPENINGNAMEPLATEAREASPA N ADJ ASSYACTION BLOCKMOUNTING SCREW HOLEN otes: 1 The Span Adj Assy is made up of the range spring, span adj shaft (threaded rod) and span adj knob. 2 The Span Adj Assy features a red color-coded range spring for a to bar (6 to 30 psig) input positioner mounts integrally to the actuator coverplate (figure 2) of the following Fisher actuators:n 1051 and 1052, size 30: The size 30 actuator is nolonger manufactured by Emerson. The 3710positioner is available for field installation onexisting size 30 1051, size 40 and 60n 1052, size 40, 60, and 70n 1061, size 30, 40, 60, and 68A mounting plate is used to mount the 3710 positionerto the following Fisher actuators:n 1051, size 33n 1052, size 20, 33n 1061, size 80, 100n 1066, size 20, 27, and 75n 2052, size 1, 2, and 3n NAMUR Mounting3710 and 3720 PositionersD200437X012 Product :3710 August 2018 7 Figure 2.

9 Mounting the positioner Base PlateMOUNTINGSCREWFEEDBACKSHAFTMOUNTINGS CREWSTIE BAREXTENSIONPOSITIONERMOUNTING PLATEW6059 Principle of OperationRefer to the positioner schematic (figure 3). Theoperational description here follows the schematiclayout and 3710 pneumatic positioner is a force-balanceinstrument that provides a control valve positionproportional to a pneumatic input signal. The balanceof opposing forces in the positioner occurs at thesumming force applied to the summing beam is developedfrom the input signal pressure on the diaphragm. Theother force is from the feedback spring and isproportional to the position of the feedback the input pressure is increased to the diaphragmof the input module, the diaphragm strokes down,increasing the effective force from the input moduleand compressing the feedback spring. The summingbeam moves the spool down in the spool body,opening output port B to supply air to the left side ofthe actuator. At the same time, output port A of thespool valve opens, allowing the right side of theactuator to vent to piston in the actuator moves to the right, rotatingthe feedback shaft and cam counterclockwise.

10 Thisrotation causes the feedback lever to rotate clockwise,increasing the compression on the feedback rotations continue until the additional forcefrom the spring balances with the input module forceon the summing beam. When the forces are equal, thesumming beam returns to its steady state or neutralposition and the actuator is held at a new a 3720 positioner , the 3722 converter receives themilliampere (mA), direct current (DC), input signal andprovides a proportional pneumatic output signalthrough a nozzle/flapper arrangement. Nozzlepressure from the converter module travels throughthe converter housing to provide the input signalpressure to the 3710 pneumatic feedback lever position is determined by thelocation or rise of the cam (figure 4) which is attachedto the feedback shaft. When the two opposing forcesare equal or at a steady state, the summing beamholds the spool in a neutral position. At steady state, asmall flow of air passes from supply through bothoutputs of the spool valve to the actuator, holding theactuator at a constant position.