TPR Valve

**Tom Cissell** · 02-15-2017, 04:04 PM

Found this on a water heater today. It is unlike any TPR valve I have seen. It has "CGA" on it which to my experience means compressed gas. Anyone know what this is?
TPRvalve.jpg

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**Jerry Peck** · 02-15-2017, 04:29 PM

That looks like an old ... VERY OLD ... temperature only ... relief valve (but the CGA is confusing, maybe it is a newer pressure only relief valve - my recollection is those old temperature only relief valves did not have that adjusting screw in the bottom of them as there was no 'adjusting' them),

It contains a lead pellet which melts at temperature and ... theoretically ... opens the relief valve.

I say "theoretically" because they are know not to work - the lead pellet melts, but the mineral deposits which have built-up inside the valve block the valve anyway.

The way to test them ... use a torch and heat the valve up from the outside until the lead pellet melts and see if the valve opens or is blocked ... of course, though, it is a one-time valve because after the lead pellet melts ... the valve needs to be replaced.

If it is a CGA pressure only valve which someone replaced on of the old temperature only relief valves with ... it still needs to be replaced ... along with the discharge line, and the ... (nothing is correct with that as shown).

Now, to make sure, there is no other relief valve installed, correct?

If there is another relief valve installed, then that may be a pressure only relief for thermal expansion ... just sayin' ... IF ... there is a proper Temperature and Pressure relief valve installed ... IF ...

**Tom Cissell** · 02-15-2017, 04:57 PM

Originally Posted by Jerry Peck

Now, to make sure, there is no other relief valve installed, correct?

If there is another relief valve installed, then that may be a pressure only relief for thermal expansion ... just sayin' ... IF ... there is a proper Temperature and Pressure relief valve installed ... IF ...

No other relief valve. The water heater was manufacture in 1986 so they have gotten their money out of it. I will recommend replacement. Thanks