Safety Relief Valves

  • Wide range of applications in all types of fluids

  • Relief Spring Sets of 10 psig to 6000 psig

  • External Set Pressure Adjustments

  • Factory Tested Set and Reseal performance

  • O-Ring Seat ensure bubble tight Shut off

End Connections
  • Powerlok® Tube End, NPT, BSPT, BSPP, ISO, DIN and JIS pipe Threads

Size range
  • 1/8” to 1” and 3mm to 25mm Tube End and Male/Female Threaded Pipe End Connections

Operating Pressure
  • Up to 60000 psig

Pressure Relief Setting
  • 10 psig to 6000 psig

Flow Rate
  • 33.3 to 78 L/min.

Relevant Design Standards


  • B31.1 Power Piping

  • B31.3 Chemical Plant and Petroleum Refinery Piping

  • B31.4 Liquid Petroleum Transportation Piping Systems

  • B95.1 Terminology for Pressure Relief Devices

  • ANSI/ASME PTC 25.3 Performance Test Code, Safety and Relief Valves


  • API RP 510 Pressure Vessel Inspection Code

  • API RP 520 Recommended Practice for the Design Installation of Pressure

  • Relieving Systems in Refineries: Part 1 Design; Part II - Installation

  • API RP 521 Guide for Pressure Relief and Depressuring Systems

  • API Standard 527 Commercial Seat Tightness of Safety Relief Valves with Metal to Metal Seats

  • API Standard 2000 Venting

  • Atmospheric and Low Pressure Storage Tanks

  • API Guide for Inspection of Refinery Equipment Chapter XVI - Pressure Relieving Devices


  • Boiler and Pressure Vessel Code

  • Section VIII - Pressure Vessels


  • MR0175

  • Oil & Gas

  • Chemical & Petrochemical

  • Power Generation

  • Process Analytical

Note: -As a drive for continuous improvements of our products, Thomas & Brian® reserves the right to change the descriptions contained in this brochure without prior notice. Consult local Agent or Factory for revisions and/or service related issues.