The Watts 40XL-7-1 is a bronze temperature and pressure relief valve with a 1" male x 1" female threaded connection.  The set pressure ranges from 150 to 210psi and 75 to 150 PSI pressure rating.  It has a steam rating of 500,000 BTU/Hour and a 210°F temperature rating.  The valve is automatic reseating, self-closing feature, has a test lever, and a 7" thermostat length.  Suitable for commercial water heater applications.

Series 40XL Automatic Reseating Temperature and Pressure Relief Valves are used in commercial water heater applications to provide automatic temperature and pressure protection to hot water supply tanks and hot water heaters. They feature a bronze body with NPT male inlet and NPT female outlet connections, unique thermostat with special thermo-bonded coating, tamper-resistant bonnet screws, automatic reseating feature, and test lever. Model 40XL has an extension thermostat for installation in the hot water outlet within the allowable distance from the top of the tank.