RParker Standard High Precision Vacuum Regulators | P3RA171 Series

The P3RA171 is a high accuracy vacuum regulator that provides uniform vacuum regulation independent of vacuum supply changes and flow demand. This unit has a diaphragm assembly with three springs to provide a more balanced loading of the diaphragm.


  • 1/4" ports (NPT)
  • Control sensitivity of .125" water column variation for use in precision applications
  • Balanced supply valve minimizes effects of vacuum variation
  • Aspirator tube compensates for downstream pressure drop under flow conditions
  • Separate control chamber isolates diaphragm from the main flow
  • Unit construction allows you to service without removing from the line



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Part Numbers

Part Number  Description

Port Size


Height (E)

mm (in)

Width (A)

mm (in)


0.5 to 30 psig springs, NPT port

1/4" 3 (w/ 650 torr supply)
151.3 (5.96) 76.2 (3.00)




Service Kits and Accessories

Part Number Description
PS20966-9 Service kit - 0-30" Hg, Nitrile, non-relieving
PS09921 Mounting bracket kit

Technical Specifications


Flow Capacity: 3 scfm (w/ 650 torr supply)
Ambient Temperature: -40°F to 200°F
Port Size: 1/4" (NPT)

Warning Triangle WARNING: These products can expose you to chemicals including lead and/or DEHP and/or carbon black, which are known to the State of California to cause cancer or birth defects or other reproductive harm.  For more information go to www.P65Warnings.ca.gov

Parker Air Preparation

Global Air Prep
  • Modular design allows for quick component change - no need to disconnect piping
  • Can be used without modular connectors using existing piping
Prep-Air II
  • Wide selection of sizes and options
  • Proven design, widely used

Stainless Steel FRLs

  • Suitable for most corrosive environments

Precision Regulators

  • Flows to 150 SFFM
  • Pressures to 500 PSIG

Electronic Proportional Regulators

  • All controls on the same face
  • Highly visible LED Display
  • Modular Mounting