Watts 174A-105 1 Relief Valve, Bronze, NPT

The Watts 174A-105 1 is a 1" pressure relief valve for hot water boiler service, factory set at 105 psi. It features a bronze body. Rated to 150 psi and up to 250°F.

This pressure relief valve has a 1 inch NPTF female inlet and outlet and a 105 psi pressure relief setpoint. The valve can be used for hot water space heating boiler applications to protect against excessive pressure.

Features

• Bronze body construction
• Automatic reseating
• Non-mechanical seat to disc alignment
• Set pressure 105 psi

Common Questions

What pressure is this valve set to?

It is factory set to relieve at 105 psi. The setting is fixed and is not field-adjustable. Note the 150 psi figure in the specifications is the maximum of the series' pressure range — the ceiling the body is built for, not this valve's relief point. This valve opens at 105 psi. Match it to the appliance nameplate: the relief setting must not exceed the working pressure stamped on the vessel you are protecting.

Is this ASME rated?

Yes. It is ASME rated and carries the "HV" code symbol under ASME BPVC Section XIII (the section that replaced Section IV for overpressure protection), and it is National Board (NBBI) certified. Inspectors look for that stamp on the valve body, and it is there.

Can I use this on potable water?

No. This is a boiler valve and is not approved for potable water, and that is true regardless of what the lead-free column says — hydronic boiler water is a closed, treated loop and is not drinking water. For a potable hot water heater or storage tank, use a T&P relief valve listed to ANSI Z21.22 / CSA 4.4 instead.

Specifications

• Type: Relief
• Size: 1"
• Inlet Size: 1"
• Outlet Size: 1"
• Connection: NPT
• Body Material: Bronze
• Max Pressure (psi): 150
• Pack Quantity: 12
• Country of Origin: United States
• Warranty: 1 Year Limited
• MPN: 174A-105 1
• Temperature: up to 250°F
• Certifications: ASME Section XIII (HV), NBBI
• Lead-Free: No
• Relief Type: Pressure Only
• Factory Set Pressure (psi): 105
• ASME Code Rating: ASME Section XIII (HV)
• Application: Hot Water Boiler
• Connection Configuration: FNPT inlet x FNPT outlet
• Automatic Reseating: Yes
• Approved for Potable Water: No
• SentryPlus Alert Flood Sensor: No