Product Description Temperature and pressure relief valve. ASME certified. Rated for 150 P.S.I. pressure and 210 deg. F. 3/4" MIPS inlet and 3/4" FIPS outlet. Extra long 2-1/2" shank. Fits most NAECA III Water Heaters. From the Manufacturer Reliance Water Heater Co 9001583-045 2-1/2" Shank Water Heater Temperature & Pressure Relief Valve.For use with water heater models requiring a 2 1/2" shank. Heavy duty Brass construction.