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The H Series of Safety Relief Valves are designed to protect refrigeration systems from overpressure situations and feature a high flow capacity. The H Series are flanged for easy replacement and can be used in a single or dual relief combination.

The H Series high capacity safety relief valves are designed and constructed to meet the requirements of ASME Boiler and Pressure Vessel Code, ANSI/ASHRAE 15-2007 Code, and they bare the ASME Code Symbol (UV), indicating compliance with these codes. Employing proven principles of design, these safety relief valves are highly reliable. Precision machined moving parts of stainless steel, a PTFE disc and a cadmium-plated spring prevent sticking due to corrosion or cold welding to ensure valve opening at the set pressure long after installation. When it comes time for replacement, the two-bolt flanged bottom inlet affords for simple removal and replacement.

Two relief valves can be mounted on a Type M dual stop valve manifold to permit either valves to be shut off individually and removed for repair or inspection. Thus, one valve is always in service as required by most codes.

• Industrial Refrigeration
• Commercial Refrigeration

Features and Benefits:

• Suitable for Use with Ammonia and Halocarbon refrigerants in non-corrosive environments
• High Capacity
• Excellent Repeatability
• All Stainless Steel Internal Parts
• Unaffected by Vibration
• Drain Plug Standard
• PTFE Seat


• Compressor Packages
• Accumulator Vessels
• Receiver Vessels
• Anywhere overpressure protection is required

Maximum Operating Temperature (C)


Maximum Operating Temperature (F)


Minimum Operating Temperature (C)


Minimum Operating Temperature (F)


Maximum Ambient Temperature (C)


Maximum Ambient Temperature (F)


Minimum Ambient Temperature (C)


Minimum Ambient Temperature (F)


Maximum Working Pressure (barg)


Maximum Working Pressure (psig)


Seat Material


Valve Materials

External: Cast Iron, Internal: Stainless Steel

Valve Type

H2 to H5

Flow Capacity (SCFM Air)

302 to 5849

Flow Capacity (Lbs. Per Min Air)

23 to 469

Inlet Connection

3/4″ FPT to 1 1/4″ FPT

Outlet Connection

1″FPT to 2″FPT

Orifice Size (mm)

15.875 mm to 34.925 mm

Orifice Size (inch)

0.625″ to 1.375″

Pressure Relief Setting (bar)

3.5 to 20.7 bar

Pressure Relief Setting (psig)

50 to 300 psig


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