Anderson Greenwood Type 84 pressure relief valve

Emerson has introduced the Anderson Greenwood Type 84 pressure relief valve (PRV), specially designed to protect tanks and vessels used in hydrogen and other high-pressure gas applications. With Arlon 3000XT thermoplastic seating and ASME SA-479 Type S21800 stainless steel spindle material, the Type 84 PRV is designed to provide leak-tight performance, resistance to embrittlement, optimum seat tightness, high reliability and long service life.

PRVs are frequently used in traditional applications, but they are not designed to handle extremely small molecules at very high pressures. Therefore, they are not ideal for hydrogen gas, which can diffuse into metals and cause embrittlement of PRV internals, increasing the risk of leaks, failures and safety problems.

To address these and other issues, Type 84 PRVs are constructed for high-pressure gas applications, with a range of 6000 psig (413 barg) to 20000 psig (1379 barg) for H2 and He, and a range of 6000 psig (413 barg) to 21,756 psig (1500 barg) for all other gases. They reach full lift at less than 5% overpressure to protect the vessel or tank to which they are affixed, with zero leakage at 90% of set pressure.

Type 84 valves feature a cartridge assembly design to apply uniform spring pressure, resulting in secure seat sealing and leak-tight performance. They are factory tested with helium and nitrogen, both accepted industry-wide as a substitute for hydrogen.