Relief valves for NH3 applications

NH3 relief valves are designed to discharge excess pressure within mainly above and underground containers, skid tanks and bulk plant installations in which they function as primary relief valves.

Product description

NH3 relief valves have internal 'pop-action' functionality which enables the valves to discharge at full capacity and not gradually if the pressure exceeds the permitted limit. Afterwards the valve will automatically return to its original position and firmly reseat.

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Body: Forged aluminium
Bonnet: Die cast aluminium
Spring: Steel
Seat disc: Resilient rubber
Diaphragm: Integrated fabric and synthetic rubber

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Gas types: NH3 (Ammonia, Anhydrous ammonia)
Connections: MNPT
Pressure range: 2 to 21.5 bar (30 to 312 psi)
Capacity: 277 to 6430 SCFM (7.87 to 182 SCMH), UL (SCFM/Air at 120% of set pressure)
Sizes and range: ½" to 2½"
Series: AA3126, AA3130, AA3135, A3149, STA1301A, MEV125, MEV250, MEV265, MEV250CN, MEV250CN and MEV265CN
Standards: UL-listed, ASME

*Materials and specifications are subject to generalisation. Our experienced people are ready to help you find the correct fit for your application. 

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  • Minimised product loss because of the 'pop action' feature
  • Automatic reseating
  • Bubble-tight seal provided by a resilient seat disc
  • ASME rated for use with anhydrous ammonia

Did you know?

Optional pipe-away adapters have grooves that will break off to protect the relief valve from damage should excess stress be applied to the piping

Valves must be protected from external damage as they are working outside container connections

Get in touch!

Whether you already know what you need, or you would like the opinion of an expert, we are always ready to help you out.