Watts 1-1/2 M116FM 150 4" Relief Valve, Ductile Iron, Flanged

The Watts 1-1/2 M116FM 150 is a 4" globe-pattern pilot-operated pressure relief / sustaining / backpressure control valve with Flanged connections. It features a ductile iron body. Rated to 175 psi.

This class 150 flanged 1 1/2 inch relief valve, both angle and globe, meets all requirements for UL listed, FM Approved fire protection service. It automatically maintains a constant pressure in the fire protection system by relieving excess pressure. The pressure relief control is normally closed, held closed by an adjustable spring setting to maintain a constant inlet pressure to the main valve.

Features

• Pressure relief control valve
• Class 150 flanged
• 175 psig rated
• Copper tubing/brass fittings

Common Questions

What is the maximum working pressure?

This unit is built as 150# Flanged and is rated to 175 psi. End connection sets the ceiling on this platform, and 150# and 300# bodies are not interchangeable — confirm the class matches your flange drilling before ordering.

Is this valve UL Listed and FM Approved for fire protection?

Yes — this model carries the UL listing and FM approval required for fire-protection service. Non-listed control valves cannot be substituted on a fire job even when the body and pilot are otherwise identical.

Specifications

• Type: Relief
• Size: 4"
• Inlet Size: 4"
• Outlet Size: 4"
• Connection: Flanged
• Body Material: Ductile Iron
• Pressure Class: Class 150
• Max Pressure (psi): 175
• Application: Fire Protection
• Operation: Pilot-Operated Diaphragm
• Country of Origin: United States
• Warranty: 1 Year Limited
• MPN: 1-1/2 M116FM 150
• Lead-Free: No
• Item Type: Valve
• Control Function: Pressure Relief / Sustaining / Backpressure
• Valve Platform: Mustang (M-Series)
• Body Pattern: Globe
• End Connection / Pressure Class: 150# Flanged
• Coating: Fusion-Bonded Epoxy
• UL Listed / FM Approved: Yes