Watts number 340-3 temperature and pressure hot water relief valve with a 1-1/2" NPT connection in an angle pattern for water heaters. This valve is set at 150 psi with a 3" thermostat extension pole and an AGA BTU rating of 1,150,000. Temperature and pressure safety relief valves are designed for water heaters to protect against overpressure conditions. They are bronze body, with a thermo-bonded coating on the thermostat probe which retards the accumulation of mineral deposits. Their maximum pressure is 150 psi and their maximum temperature is 210°F.