Thread: TP&R piped into gas line at water heater

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Never seen one in person, but I believe that is the Watts TPR gas valve. There's another name (Watts 210?). It's for a land locked water heater, so that the heater will shut down by stopping the gas flow instead of the relief valve opening and discharging water.

I'm sure others will have more to say.

That makes sense Jim, it was in a 2nd story condo. Thanks for the reply. I'm going to look up the "watts 210" TP&R valves.

Jim nailed it.

When the T&P relief goes off, the gas shuts down, which immediately stops heating the water, which stops building pressure in the tank, keeping the pressure in the tank to within its safe limits so it does not become a bomb and a rocket and go BOOM! WHOOSH! flying through the air where it lands and takes out something else too.

Thanks guys. I looked it up, your right on!

Just curious, how could it be operated(tested).

That is only the temperature side of the T&P valve protection requirement. The heater still needs a pressure relief valve installed. Look at the "three acceptable position sketches" on the web site.
T.

Very interesting, learn something new everyday here. Heres a link to some documentation. http://www.plumbersurplus.com/pdf/01146.pdf

Originally Posted by Rick Cantrell

Just curious, how could it be operated(tested).

In a search to answer this question I found the following informative link. BTW, it does not mention a testing method.

i-Course.com : Home Inspector Training Courses Education Online School and Licensing

Originally Posted by Tony Watson

That is only the temperature side of the T&P valve protection requirement. The heater still needs a pressure relief valve installed. Look at the "three acceptable position sketches" on the web site.
T.

Plumbers here never install the pressure relief valve. I keep copies of the Watts installation instructions in my car, as well as a PDF on the computer, so that I can educate them.

While the Watts 210 installation instructions say you need a relief valve, it sort of begs the point for the 210 in the first place.
No where to drain the damn thing! There should be a relief valve on the cold system after the regulator.

The instructions illustrate three different methods of installation depending upon how many holes you have to tap in the tank but each includes a TPR somewhere in the piping.

You would have to heat the water to 210F to test it. Hmmm, maybe that's why its model number is 210? ;-)

The requirement for these valves would probably be limited to jurisdictions and communities where it is a local ordinance or required by a HOA--not typically found in residential settings.

Safety controls can be great but the downside is they add one more thing to go wrong or be installed improperly in the first place.

Bob

In my early days in the plumbing trade this was common using a Kitson Valve. Same principal as the Watts 210 . I have not seen the valve used (installed) since ASME rated valves hit the market. The old Kitsons were used to control water heater discharge do to temperature overheating. In that time period Watts made pressure relief valves. They also made T&P but the temperature was a meltable plug, when they went off they did not shut. The discharge ran until a valve was manually shut.

You might be interested in the following.

On www.parrsplumbing.com click on water heater explosions that will take you to a blog. News paper clippings and photos in the sixties.

Enjoy the booms ... And read my paper on water heater explosions today!

i don't know if it makes any difference but 210's are not listed for usa just canada. breid............