Rockwood Swendeman

Cryogenic Service RXSO Bronze Safety Relief Valves

Rockwood Swendeman Pressure Relief valves are safety devices designed to protect pressurized vessels, lines or systems during an overpressure event. The recommendations below are general and it is the responsibility of the user to assure that installation and maintenance are in accordance with the applicable ASME Codes and local requirements.


  • Special Teflon® seat,making bubble-tight seals possible to over 90% of set pressures per spec API 527; not applicable to steam.
  • Adjustable blowdown ring.
  • Meets A.S.M.E. Boiler and Pressure Vessel Code, Section VIII requirements.
  • Especially recommended for those applications where corrosive or expensive gases benefit from stainless steel construction.
  • Works with set pressures to 400 psi, and temperatures from minus (-)423° to plus (+)400°F
  • Cleaned and packaged for us in O2 service in compliance with the CGA specification G-4.1
    • Additional Cleaning Specifications:
      - 4WPI-SW70003
      - ES.660.503
      - GS-38
      - GS-40


  • Especially recommended where noxious or expensive liquids or gases place a premium on seal quality
  • Stationary Cryogenic storage tanks
  • Dual Safety relief systems
  • Overpressure relief of tanks, pipelines, vessels, pumps
  • Air and gas compressors
  • Corrosive industrial applications


  • Large and Extra Large Capacity
  • BSP threads on most sizes
  • Lever Operation
Technical Data
Operating Ranges
- Temperature: -423F to +400F
- Set Pressures: 0 to 400 psig
Materials of Construction
- Shell: Cast Bronze,
- Base: Forged Brass,
Alloy C37700
- Trim: Copper Alloy
- Spring: Stainless Steel
17-7 PH A.S.T.M.
A-313, Type 631
- Each Valve is set, tested, retested and sealed at the factory to the customer's specifications
- Inlet 1/2" to 2"
- Outlet 3/4" to 2-1/2"

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