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Relief Valves

Proportional Relief Valves

Proportional Relief Valves


  • Provide simple, reliable, over-pressure protection for a variety of general-industry applications
  • Have easy external set pressure adjustment

High-Pressure Proportional Relief Valves (R3A Series and R4 Series)


Working Pressures up to 6000 psig (413 bar)
Springs multiple springs available for a selection of pressure ranges

Low-Pressure Proportional Relief Valves (RL3 Series and RL4 Series)


Working Pressures up to 300 psig (20.6 bar)
Springs one spring for the full set pressure range

Proportional Relief Valves (R3A,R4, RL3, and RL4 Series)


Seal Materials Fluorocarbon FKM is standard. Buna N, ethylene propylene, and neoprene are available factory-installed or in replacement seal kits for field assembly.
Spring Kits Replacement spring kits are available for all models
Manual Override Handles A manual override handle opens the valve without changing the set pressure. Available factory-installed or in kits for field assembly.
Special Cleaning and Packaging Swagelok Special Cleaning and Packaging (SC-11) to ensure compliance with product cleanliness requirements stated in ASTM G93 Level C.

Proportional Safety-Relief Valve, High-Pressure (PRV Series)



Working Pressures up to 5800 psig (400 bar)
Set Pressure 145 to 6000 psig (10.0 to 413 bar)
Seal Materials Fluorocarbon FKM and nitrile

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Safe Product Selection: The complete catalog contents must be reviewed to ensure that the system designer and user make a safe product selection. When selecting products, the total system design must be considered to ensure safe, trouble-free performance. Function, material compatibility, adequate ratings, proper installation, operation, and maintenance are the responsibilities of the system designer and user.

⚠ Warning: Do not mix/interchange Swagelok products or components not governed by industrial design standards, including Swagelok tube fitting end connections, with those of other manufacturers.