Watts 4 M1116FM 300X 150 8" Relief Valve, Ductile Iron, Flanged

The Watts 4 M1116FM 300X 150 is a 8" angle-pattern pilot-operated pressure relief / sustaining / backpressure control valve with Flanged connections. It features a ductile iron body. Rated to 300 psi.

This class 300x 150 relief valve 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 300x 150 flanged
• 300 psig rated
• Copper tubing/brass fittings

Common Questions

What is the maximum working pressure?

This unit is built as 300# Flanged and is rated to 300 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: 8"
• Inlet Size: 8"
• Outlet Size: 8"
• Connection: Flanged
• Body Material: Ductile Iron
• Pressure Class: Class 300
• Max Pressure (psi): 300
• Application: Fire Protection
• Operation: Pilot-Operated Diaphragm
• Country of Origin: United States
• Warranty: 1 Year Limited
• MPN: 4 M1116FM 300X 150
• Lead-Free: No
• Item Type: Valve
• Control Function: Pressure Relief / Sustaining / Backpressure
• Valve Platform: Mustang (M-Series)
• Body Pattern: Angle
• End Connection / Pressure Class: 300# Flanged
• Coating: Fusion-Bonded Epoxy
• UL Listed / FM Approved: Yes