What is this??

this was installed on the cold side of the water heater line. Had an extension like T&P, but never seen this one before.

any clue? Looked like some type of spring loaded valve.

Pressure relief only.

In place of an expansion tank.

Why would you need 2 out of curiosity?

The one you are showing is set far lower than the the TPR. Probably around 100 P.S.I.

The water heater TPR would still function if the inlet valve was closed and the heater ran wild.

Well thats not good, cause the water pressure was 100 when tested this AM. drip drip drip…:smiley:

I added to the post above.

The pressure can be set on that on below the hex nut.

It it’s dripping I would recommend repair by a qualified person.

It wasnt dripping yet, but the drain was not directed into the pan. The report was revised. Thanks Mr. Larson.

Remember how they put fuses on both sides of knob and tube wiring?
In certain locations there is a one way valve on the water line at the street. If there is no expansion tank in the home the TPR may leak.