TPRV Discharge Question

OK I did an inspection a few weeks ago and 1 item noted was the lack of any water heater discharge pipe. They asked me to go reinspect that and other items I called out. OK all was done satisfactorily except the discharge is copper with some type of metal (looks brass or something to me)l fittings? also they appear to ba a compression type. My concern is the “dissimilar” metals ? is this a No No or is it acceptable? I think it’s a no no


Those look like shark bite fittings which I don’t see a problem with. But, it looks like they used 1/2" copper, instead of keeping the 3/4" that exits the TPR valve, which would be a no-no if reduced.

Gator bite, shark bite…looks fine to me. Looks 3/4" to me.

Joe, so you think this “repair” is ok ?


I can’t tell the size for sure but it must be 3/4 " minimum without exception.

The galvanized nipple should be cleaned and monitored for future leaks. Other than that, the connectors are common and I don’t have a problem with them. My house is full of them.

Brass and copper are interchangeable due to their similar make up but the galvenized to brass is a concern.

Probably not a problem for a TPR discharge.

Thanks gang for the replies, I just wanted to hear some others opinions.


Probably true due to the lack of an electrolyte unless there is enough in the surrounding air.

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So true! I just completed a bathroom reno and used 2 Sharkbite “T” 's to connect PEX to copper line. Fitting were $7.50 each and $2.00 for the plastic disconnect tool. They do work slick, though!

Nathan I agree and have seen that too when shopping. It is funny also to see renovators picking up supplies with no paper or plans discussing measurements ect. LOL
HOME DE POT is the worst.

What would be the pressure rating for that type of connection . Anyone know?

200 PSI 200 F

That could be problematic:
Temperature and Pressure (T&P) relief valves
Temperature and pressure (T&P) relief valves used on residential water heaters are typically designed and manufactured to relieve on pressure at 150 psig and on temperature at 210 degrees F. These ASME, ANSI and CSA (AGA) approved relief valves protect the water heater from excess pressures and temperatures by discharging water.

Oh how many calls I have received about the approval of plastic discharge.
No writing and sold at Canadian tire and Home Depot.
There are ones approved and the writing is stamped on the stem.
But you are right Larry! 210 degrees F is the min.

It is only a concern if you want to nit-pik. This is not a pipe with anything in it full time except air!

Problem matic if your standing by it if blows , so there you have it so i would write it to be changed small change to make it safe .