External “Pop-Action” Pressure Relief Valves for ASME Containers and Bulk Plant Installations AA3126, AA3130, 3131, 3132, 3133, 3135, AA3135, and A3149 Series


Designed for use as a primary relief valve on ASME above ground and underground containers, bulk plant installations and skid tanks. The 3131 Series may also be used as a primary or secondary relief valve on DOT cylinders, or as a hydrostatic relief valve. All working components of these relief valves are outside the container connection, so the valves must be protected from physical damage.


    • “Pop-action” design keeps product loss at a minimum.
    • Relief valve designed to automatically reseat firmly after discharge.
    • Resilient seat disc provides “bubble-tight” seal.
    • 3149 relief valves incorporate integral pipeaway adapter with break off groove that protects the valve from piping stress damage.
    • Optional pipeaway adapters have grooves that will break off to protect the relief valve from damage should excess stress be applied to the piping.
    • 3149 relief valves include weep hole deflectors, installed to guard against flame impingment on adjacent containers.
    • Most are ASME rated for use with LP-Gas and anhydrous ammonia.


Body Brass
Spring Steel
Stem Stainless Steel
Seat Disc Resilient Rubber