Watts 0254702 3/4 In Bronze Automatic Reseating Temp And Pressure Relief Valve, 150 psi, 210 degree F, 3 In Thermostat, Female Connections

Inlet and outlet are both 3/4 inch female NPT on the Watts 140 Series 0254702, so it threads onto a 3/4 inch male nipple rather than directly into a female tank tapping. If the heater's T&P port is female, you need a short 3/4 inch NPT nipple of the right length to place the probe correctly in the tank.

Temperature steam discharge capacity is 180,000 BTU per hour, and that is the number that has to equal or exceed the input rating of the water heater it is protecting. Pressure steam discharge capacity is far higher at 1,437,600 BTU per hour. For a residential gas heater at 40,000 to 75,000 BTU input, the 180,000 figure leaves plenty of margin; on a commercial heater above 180,000 BTU input, size up to a larger valve.

Yes on both counts. The 0254702 is an automatic reseating valve with a manual test lever, so it closes back off once temperature and pressure drop to normal, and maintenance can lift the lever to verify it is free. That reseating behavior is what property managers want on a fleet of heaters, since a one-shot valve would need replacing after every event.

The body on the 0254702 is bronze, which is the standard choice for potable hot water service on storage heaters because it resists dezincification and scale attack better than lower-grade brass. On a maintenance replacement schedule across many units, that matters more than the up-front difference.