Fisher 2625, 2625SST, and 2625NS Volume Boosters

1 2625, 2625 SST, and 2625NS VolumeBoostersA Fisher 2625, 2625 SST, or 2625NS Volume booster ispart of the 2625 series Volume Boosters and is used inconjunction with a positioner on a throttling controlvalve to increase stroking speed. The 2625NS is anuclear service version and uses elastomericcomponents that better withstand high temperatureand radiation booster incorporates fixed deadband, soft seatconstruction, and an integral bypass restriction toeliminate positioner saturation problems that canoccur with Volume Boosters that do not have thesefeatures. Adjustment of the integral bypass restrictionis necessary for system stability. This adjustment doesnot affect the deadband of the Volume booster , butdoes permit the control valve to respond to small inputsignal changes without sacrificing steady stateaccuracy.

2 It also allows the booster to deliverhigh Volume output for fast stroking when large, rapidinput signal changes Volume booster is used to improve stroking precision valve control is required, the use of apositioner is recommended. If the Volume booster is tobe used for on/off control, the integral bypassrestriction on the booster must be closed (turned fullyclockwise).Connectors and piping can be installed with either2625, 2625 SST, or 2625NS Volume booster fordiagnostic 2625 and 2625 SST are certified for use in SafetyInstrumented System (SIS) applications. Certification isby exida Consulting LLC, a global provider of functionalsafety and control system security.

3 SIS certification isidentified on the product by the EXIDA logo on the2625 Fast Response booster delivers the Volume neededfor rapid actuator stroking when large inputchanges suddenly Adjustable Response Integral bypass restrictiontunes the booster response so that smooth actuatormotion follows the slow signal Efficient Operation Soft seats provide tight shutoffto reduce unnecessary air consumption andeliminate saturation of positioner Maintains Accuracy booster permits high actuatorstroking speeds upon demand without degradingthe positioner steady state SIL 3 Capable - Certified for use in SafetyInstrumented System (SIS) , 2625 SST, 2625NS Volume BoostersD200071X012 Product :2625 August 20182625, 2625 SST, 2625NS Volume BoostersD200071X012 Product :2625 August 2018 2 SpecificationsSupply Pressure RangesWhen used in conjunction with a positioner or otherpneumatic accessory, always pipe the positioner andvolume booster with one common supply through aFisher 67D, 67DR, or 95H regulator (see figure 2).

4 Ahigh capacity filter, such as the Fisher 262K, shouldbe installed in the supply line to the regulator. Supplypressure also must not exceed the maximumpressure rating of the actuator. Constructions areavailable in two maximum supply Normally Used With Diaphragm Actuators: Upto bar (40 psig)When Normally Used With Piston Actuators: Up bar (150 psig)Input Signal PressurePositioner outputMaximum Input Signal bar (150 psig)Fixed Input to Output Pressure Ratio1 to 1 Nominal DeadbandPercent of positioner Output Span(1) mm ( inch) exhaust port: 2% mm ( inch) exhaust port: mm ( inch) exhaust port: 5%Construction MaterialsBody: Aluminum or CF8M (316 SST, cast)Seat Ring: Brass or S31600 (316 SST)Diaphragms2625 and 2625 SST Standard: Nitrile/nylon High Temperature: FKM/TPES2625NS.

5 EPDM/meta aramidUpper and Lower Valves2625 and 2625 SST Standard: Nitrile/aluminum/stainless steel High Temperature: FKM/aluminum/stainless steel2625NS: EPDM/aluminum/stainless steelO Rings2625 and 2625 SST Standard: Nitrile High Temperature: FKM2625NS: EPDMC onnectors for Diagnostic Testing: JStainless steelor JbrassOperative Temperature Limits(2)2625 and 2625 SST Standard: -40 to 71_C (-40 to 160_F) High Temperature: 0 to 121_C (32 to 250_F) 2625NS : -40 to 93_C (-40 to 200_F)ConnectionsInput Signal: 1/4 NPTS upply and Output: 3/4 NPTPort Diameters(3)Supply Port: J mm ( inch) orJ mm ( inch)Exhaust Port: J mm ( inch)(4),J mm ( inch) or J mm ( inch)Maximum Flow CoefficientsSee table 1 Hazardous Area ClassificationComplies 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*XSafety Instrumented System ClassificationSIL3 capable - certified by exida Consulting LLCA pproximate WeightAluminum: kg (5 lb)Stainless Steel: kg ( lb)NOTE.

6 Specialized instrument terms are defined in ANSI/ISA Standard - Process Instrument Zero to maximum The pressure/temperature limits in this document and any applicable code or standard should not be May be used in any Aluminum 2625 Volume booster , 2625 SST, 2625NS Volume BoostersD200071X012 Product :2625 August 2018 3 Figure 1. Sectional View of Volume BoosterINPUT SIGNALBYPASS RESTRICTIONADJUSTING SCREWBYPASSRESTRICTIONSUPPLYPORTOUTPUT TOACTUATORSUPPLYEXHAUSTEXHAUSTPORTDIAPHR AGMSW0679 1 Principle of OperationRefer to figures 1 and 2. Because of the bypassrestriction, large input signal changes register on thebooster input diaphragm sooner than in the large, sudden change in input signal causes apressure differential to exist between the input signaland the output of the booster .

7 When this occurs, hediaphragms move to open either the supply port or theexhaust port, whichever action is required to reducethe differential. The port remains open until thedifference between the booster input and outputpressures returns to within the deadband limit of thebooster. With the bypass restriction adjusted for stableoperation, a signal with small magnitude and ratechanges passes through the bypass restriction and intothe actuator without initiating booster supply and exhaust ports remain closed,preventing unnecessary air consumption and possiblesaturation of positioner , 2625 SST, 2625NS Volume BoostersD200071X012 Product :2625 August 2018 4 Figure 2.

8 Typical InstallationsVOLUMEBOOSTERPOSITIONEROUTP UTSIGNALPOSITIONERACTUATOR67D, 67DR OR 95 HSUPPLYNote: 1 Connection location for diagnostic testingWITH A PISTON ACTUATORWITH A DIAPHRAGM ACTUATORA0794 3E1407 SIGNALDIGITAL VALVE CONTROLLERACTUATOR67D, 67 DROR 95 HVOLUMEBOOSTERVOLUMEBOOSTERSUPPLYOUTPUT AOUTPUT BTable 1. Maximum Flow Coefficients(1)PORT SIZE COMBINATIONSCOEFFICIENTSS upply PortExhaust PortSupply PortExhaust DVC6200, DVC6200 SIS, DVC6200f, DVC6200p, DVC6000, DVC6000 SIS, DVC6000f digitalvalve DVC2000 digital valve controller Low Pressure Relay High Pressure 3570 valve 3582 valve 3610J, 3610JP, 3611JP, 3620J, 3620JP, 3621JP valve Consult your Emerson sales office or Local Business Partner for special stroking speed , 2625 SST, 2625NS Volume BoostersD200071X012 Product :2625 August 2018 5 Figure 3.

9 DimensionsA0807 33/4 14 NPTSUPPLY CONN9 EXHAUSTHOLES 7 ( ) DIA1/4 18 NPT INPUT CONN21( )111( )48( )3/4 14 NPTOUTPUT TO ACTUATOR121( )60( )mm(INCH) 2625NS for NuclearService ApplicationsThe 2625NS Volume booster uses EPDM(ethylene propylene) elastomeric parts. These partshave superior resistance to degradation at elevatedtemperature and radiation levels. This version isdesigned for nuclear service applications where oil freesupply air is 2625, 2625 SST, and 2625NS are available assafety related items when processed using thecommercial grade dedication section of the 10 CFR50,Appendix B, quality assurance program. 10 CFR21reporting is also part of the safety related processingprogram.

10 Seismic operability testing has been done toqualify both versions as rigid items at levels up to 9g'suniaxial (in each axis). Further nuclear servicequalification data is available on , 2625 SST, 2625NS Volume BoostersD200071X012 Product :2625 August 2018 6 InstallationFigure 2 shows typical installations for the 2625, 2625 SST, or 2625NS Volume booster on piston anddiaphragm actuators. A single regulator that suppliesboth the positioner and booster (or Boosters ) isrecommended. The supply medium must be clean,dry, oil free air or non corrosive a clean, dry, oil free air supply with instrumentscontaining EPDM components. EPDM is subject todegradation when exposed to petroleum base in mind that many actuators require larger casingor cylinder connections to take full advantage of thebooster's ability to deliver its high Volume are shown in figure 3.