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G-Series Pressure Relief Valves

3D CAD Drawings Available

Griffco G-Series medium-flow pressure relief valves are designed to protect chemical feed systems from over pressure damage caused by defective equipment or a blockage in the chemical feed line. Robust construction ensures reliability in the rigorous service of municipal and industrial applications. Also called bypass pressure valves.

G-Series Medium-Flow Pressure Relief Valves

Valve Features

  • Anti-siphon function
  • 2-port and 3-port configurations (90° and 180°)
  • Solid, robust, machined construction
  • Flanged, union, threaded and socket connection options
  • Molded Noryl top with integral hardware locking
  • 316L SS metal valve and top options
  • Molded PTFE/EPDM diaphragm
  • Adjustable up to 350 psi (24 bar)
  • 4 optional pressure ratings (springs)
  • Valve sizes from 1/2″ to 4″ or DN 15 to DN 100
  • Tamper-resistant adjustment screw
  • High-temperature option up to 300°F (149°C)

Griffco Benefits

  • High reliability at affordable price
  • Long diaphragm life
  • Wide range of valve materials
  • Multiple diaphragm material options
  • Factory or field settable
Available SizesWetted Materials
1/2″ to 4″ or DN 15 to DN 100PVCHalar®
CPVC316 SS
PolypropyleneAlloy 20
PVDFHastelloy® C
PTFE

M-Series PRM – Data Sheets

SizeMaximum FlowMaximum Pressure
PulsatingContinuous
InchMetricGPHLPHGPMLPMPSIBAR
1/2″DN 153201,211176335024
3/4″DN 203671,399197235024
1″DN 254621,748249035024
1-1/2″DN 401,3885,2547227525017
2″DN 501,5335,8038030225017
3″DN 805,15719,5212701,02025017
4″DN 1005,15719,5212701,02025017

G-Series PRG – Data Sheets

TitleDescriptionDate modifiedDownload
Data Sheet PRG (US)Imperial09-14-2020Download
Data Sheet PRG (Intl)Metric09-14-2020Download
Data Sheet PRG (Spanish)Metric09-14-2020Download

G-Series PRG – IOM Manuals

TitleDescriptionDate modifiedDownload
IOM Manual PRG (US)Imperial05-21-2021Download
IOM Manual PRG 3″ & 4″ (DN 80 & DN 100)Imperial09-14-2020Download
IOM Manual PRG (Spanish)Metric09-14-2020Download

G-Series PRG – Dimensional Drawings

G-Series 3-Port @ 180° (1/2″ – 1″) (DN 15 – DN 25)

TitleDescriptionDate modifiedDownload
Dim PRG1 3Port@180 Threaded US1/2″ – 1″08-24-2020Download
Dim PRG1 3Port@180 Threaded MetricDN 15 – DN 2508-24-2020Download
Dim PRG1 3Port@180 Socket US1/2″ – 1″08-24-2020Download
Dim PRG1 3Port@180 Socket MetricDN 15 – DN 2508-24-2020Download
Dim PRGF 3Port@180 Flanged US1/2″ – 1″08-24-2020Download
Dim PRMU 3Dim PRGF 3Port@180 Flanged MetricDN 15 – DN 2508-24-2020Download
Dim PRGU 3Port@180 Union US1/2″ – 1″08-24-2020Download
Dim PRGU 3Port@180 Union MetricDN 15 – DN 2508-24-2020Download

G-Series 2-Port @ 180° (1/2″ – 1″) (DN 15 – DN 25)

TitleDescriptionDate modifiedDownload
Dim PRG2 2Port@180 Threaded US1/2″ – 1″08-24-2020Download
Dim PRG2 2Port@180 Threaded MetricDN 15 – DN 2508-24-2020Download
Dim PRG2 2Port@180 Socket US1/2″ – 1″08-24-2020Download
Dim PRG2 2Port@180 Socket MetricDN 15 – DN 2508-24-2020Download
Dim PRG2F 2Port@180 Flanged US1/2″ – 1″08-24-2020Download
Dim PRG2F 2Port@180 Flanged MetricDN 15 – DN 2508-24-2020Download
Dim PRG2U 2Port@180 Union US1/2″ – 1″08-24-2020Download
Dim PRG2U 2Port@180 Union MetricDN 15 – DN 2508-24-2020Download

G-Series 2-Port @ 180° (1-1/2″- 2″) (DN 40 – DN 50)

TitleDescriptionDate modifiedDownload
Dim PRG2 2Port@180 Threaded US1/4″ – 1/2″08-24-2020Download
Dim PRG2 2Port@180 Threaded MetricDN 40 – DN 5008-24-2020Download
Dim PRG2 2Port@180 Socket US1-1/2″- 2″08-24-2020Download
Dim PRG2 2Port@180 Socket MetricDN 40 – DN 5008-24-2020Download
Dim PRG2F 2Port@180 Flanged US1-1/2″- 2″08-24-2020Download
Dim PRG2F 2Port@180 Flanged MetricDN 40 – DN 5008-24-2020Download
Dim PRG2U 2Port@180 Union US1-1/2″- 2″08-24-2020Download
Dim PRG2U 2Port@180 Union MetricDN 40 – DN 5008-24-2020Download

G-Series 2-Port @ 180° (3″ – 4″) (DN 80 – DN 100)

TitleDescriptionDate modifiedDownload
Dim PRG5 2Port@180 Flanged US3″ – 4″08-24-2020Download
Dim PRG5 2Port@180 Flanged MetricDN 80 – DN 10008-24-2020Download

G-Series 2-Port @ 90° (1/2″ – 1″) (DN 15 – DN 25)

TitleDescriptionDate modifiedDownload
Dim PRG290 2Port@90 Threaded US1/2″ – 1″08-24-2020Download
Dim PRG290 2Port@90 Threaded MetricDN 15 – DN 2508-24-2020Download
Dim PRG290 2Port@90 Socket US1/2″ – 1″08-24-2020Download
Dim PRG290 2Port@90 Socket MetricDN 15 – DN 2508-24-2020Download
Dim PRG290F 2Port@90 Flanged US1/2″ – 1″08-24-2020Download
Dim PRG290F 2Port@90 Flanged MetricDN 15 – DN 2508-24-2020Download
Dim PRG290U 2Port@90 Union US1/2″ – 1″08-24-2020Download
Dim PRG290U 2Port@90 Union MetricDN 15 – DN 2508-24-2020Download

G-Series 2-Port @ 180° (1-1/2″- 2″) (DN 40 – DN 50)

TitleDescriptionDate modifiedDownload
Dim PRG290 2Port@90 Threaded US1-1/2″- 2″08-24-2020Download
Dim PRG290 2Port@90 Threaded MetricDN 40 – DN 5008-24-2020Download
Dim PRG290 2Port@90 Socket US1-1/2″- 2″08-24-2020Download
Dim PRG290 2Port@90 Socket MetricDN 40 – DN 5008-24-2020Download
Dim PRG290F 2Port@90 Flanged US1-1/2″- 2″08-24-2020Download

M-Series PRM – Sectional Drawings

TitleDescriptionDate modifiedDownload
G001PRV 3-Port08-26-2020Download
G0022-Port, PRV 3-Port08-26-2020Download

3D CAD Drawings Now Available

Three-dimensional CAD drawings are now available for you to download and use in your pumping system designs.

G-Series 3D CAD Drawings