Specifications
Types 81, 83, 86 Safety Valves
The Type 81 direct spring operated safety valve, with an inert plastic seat, is suitable for a wide range of products, pressures, and temperatures involving gas, vapor, and liquid or gas thermal relief applications. It allows maintained tightness close to set pressure, opens fully at set pressure, and provides a safe, external adjustment for short blowdown. The Type 81 valve is best suited for cryogenic, high set pressure, and chemically active applications.
Orifice Sizes: 0.049 in² [0.32 cm²] and D through J
Connections: 1/2” x 3/4” to 2” x 3”
Inlet Flange Ratings: ANSI 150, 300, 600, 900, 1500, 2500
Maximum Temperature: 550°F [288°C]
Minimum Pressure: 20 psig [1.4 barg]
Maximum Pressure: 10,000 psig [690 barg]
Type 81P Relief Valve for Liquid Service
Type 81P Relief Valve The Type 81P is a soft-seated, balanced, direct spring operated pressure relief valve intended for liquid applications. This valve is rated at full capacity at 10 percent overpressure and meets the latest requirements of Section VIII, Division 1 of the ASME Unfired Pressure Vessel Code.
Orifice Sizes: 0.049 in² [0.32 cm²] and E, G and J
Connections: 3/4” x 1” to 2” x 3”
Inlet Flange Ratings: ANSI 150, 300, 600, 900, 1500, 2500
Maximum Temperature: 400°F [204°C]
Minimum Pressure: 50 psig [3.4 barg]
Maximum Pressure: 6,000 psig [414 barg]
