Okay to not install expansion tank for domestic?

sunlight33

If there is no backflow preventer installed on city water, is there any benefit to install an expansion tank (for indirect water heater)? I have been living in my house for several years and recently I have a chance to redo the plumbing so I am wondering if I should take this opportunity to add a tank.

pecmsg

Add the tank. Eventually you’ll get a back flow preventer. 

JUGHNE

Or if you add a recir system for DHW you would need a check valve on the cold.
I would add a tee for future connection of the tank. Even a tee with a valve so you would not have to drain down to add or change tank.

dopey27177

Why add the tank?
Install the back flow preventer, do not forget that probably is a code item and will need a plumber with a lic. or certification.

Also do what Jughe said, future also find ways to jump up and and become now.

jake

EBEBRATT-Ed

What @JUGHNE said.

I wouldn't add a tank unless you have to. Just another thing to have to maintain and eventually fail

sunlight33

Yeah I will probably add a tee with a threaded cap.

Larry Weingarten

Hi @sunlight33 , What's the static pressure you're working with?

Yours, Larry

sunlight33

50 psi

Larry Weingarten

Hi, with that pressure, I see no reason why a reducer or other backflow device will be needed any time soon. Simple is good. I’d skip the expansion tank.

Yours,,Larry

hot_rod

It's not uncommon for the water utility to upgrade the meter or meter yoke to a BFD type, then you will see relief valves start seeping or pop off.

Install a stainless or bag type expansion tank and it will probably outlast the tank.

ChrisJ

I wouldn't add anything that's not needed.

Maybe they will require a BFP, maybe they won't and if they do no one knows how many decades from now it could be.

If it does happen do what's required at the time and you'll have a nice new tank then.