Watts 40XL-4-1 Temperature and Pressure Relief Valve

The Watts 40XL-4-1 Temperature and Pressure Relief Valve provides essential safety for commercial water heaters. Designed with automatic reseating and a self-closing lever, it reliably releases excess temperature and pressure to protect equipment and personnel.

This valve features a bronze body with 1 inch inlet and outlet connections (male thread x female threaded), a set pressure range of 150–210 PSI, a temperature rating of 210°F, and a pressure rating of 75–150 PSI. It includes an extension thermostat, a 4-inch thermostat length, and a test lever, along with non-mechanical seat-to-disc alignment and a tamper-resistant bonnet screw for added reliability.

Ideal for commercial water heaters, it meets multiple standards including ANSI Z21.22, ASME, CSA, ASSE, FM, NSF, UL, ULC, NB, and FHA.

• Automatic reseating and self-closing lever
• Bronze body with 1" NPT inlet/outlet connections (male thread x female thread)
• Set pressure range 150–210 PSI; temperature rating 210°F
• Temperature/steam rating up to 500,000 BTU/hour
• Extension thermostat (4") and test lever
• Tamper-resistant bonnet screw; non-mechanical seat-to-disc alignment
• End connections: male threaded x female threaded
• Certification-ready for commercial water heaters