buffer tanks

Kniggit

Wouldn't a steel nipple "heal" if there was a small enough leak that you missed it on your first check.

Just another thought.

bob elmore

buffer tank

I know some of you have used residential electric
water heaters as buffer tanks. can anyone tell me if the
element tappings are standard pipe thread?

thank you
bob

John Starcher_4

1\" NPT.....

....works. With a healthy dose of teflon and pipe dope.

hr

Sort of

1" NPT will thread into it and seal with teflon as John mentioned.

However the element depends on the rubber gasket ring to seal, as the thread really isn't all that deep and probably not really a taper thread like a NPT thread.

I have used a couple dozen without any leaks. I use either a 1" male by 1" copper adapter, or you can actually find a 1" male by 1-1/4" copper adapter, shown here, for additional flow requirements.

hot rod

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John Starcher_4

Exactly, HR.....

....and I have always been a bit nervous about the seal of the threads. I usually use the copper adapters that you mentioned. I've been tempted to try using the heater element gasket in conjunction with the copper fitting, but so far I have been successful just wrapping the male threads with teflon, then applying pipe dope.

The relatively low system pressure works in our favor, also.

Starch

Alex Giacomuzzi

Pressure Safety Valve Question on a Buffer Tank..

Pardon me for tagging on to a connection question regarding an electric water heater tank. A separate question regarding the use of a residential electric water heater tank as a buffer tank ----

If the boiler system already has a 30 PSI pressure safety value installed on or with it, does the code require a separate PSV or some other means of tank protection on the buffer tank??

Thanks Alex

Brad White_153

No harm in tagging onto another thread

so long as it is not hijacked you understand that it may get lost... Posting as your own thread is the best way to get focussed replies and not dilute the original poster's thread.

To answer your question though, if the tank can be isolated (valved off) from the boiler's pressure relief valve, it needs it's own relief valve. It is an unfired pressure vessel and if isolable and without and expansion tank and a relief valve, the pressures of expansion could build exponentially and burst. Having a relief valve is cheap insurance. Best $20 you could spend and hindsight after a burst need not exist.