Expansion Tank Mounting -- can I use previous relief port?

[Mr_David]

It had a spring and a small rubber ball (stopper). When the pressure exceeds the spring rate, it opens and allows water to pass. The white tube routes down to the pan drain hole, about 3 inches down the drain pipe.

See explanation above on the Watts valve. I've seen them in several plumbing stores and online. I'd feel ok about mounting the expansion tank on it, but I'd have to use at least two adapters to get from 3/8 to 3/4 and don't want to do that.

I learn new things every day.
I will admit I don't know everything, Just don't tell my wife.
I ALMOST have her convinced.

 

[KULTULZ]

I would swap that 90 out for a tee and put the tank on the vertical above the tee on a fem adapter.

If going to an expansion tank (good idea IMO), the COMB Ball and Press Relief Valve should be removed and replaced with just a ball valve to cut off water to the WH.

You don't know the value of the valve release pressure and if it is @ 125psi a whole lot of damage can occur in the distribution system before it opens and you also are losing a lot of water. The tank will be able to absorb the thermal expansion pressure.

 

[Deerslayer]

If going to an expansion tank (good idea IMO), the COMB Ball and Press Relief Valve should be removed and replaced with just a ball valve to cut off water to the WH.

You don't know the value of the valve release pressure and if it is @ 125psi a whole lot of damage can occur in the distribution system before it opens and you also are losing a lot of water. The tank will be able to absorb the thermal expansion pressure.

As long as the static pressure of the home is 80 psi or less then yes you could remove it. But who knows someone could've installed this instead of a proper prv.

 

[KULTULZ]

As long as the static pressure of the home is 80 psi or less then yes you could remove it. But who knows someone could've installed this instead of a proper prv.

You're right. It (combo ball/pressure relief valve) might be an 80# or 125# release, but who knows? He has to verify a PRV install or not, w or w/o a check valve feature. He then has to establish delivered house pressure with the WH turned off and go from there.

Or he could simply move the valve drain indoors and get away from the freezing.

 

[Deerslayer]

You're right. It (combo ball/pressure relief valve) might be an 80# or 125# release, but who knows? He has to verify a PRV install or not, w or w/o a check valve feature. He then has to establish delivered house pressure with the WH turned off and go from there.

Or he could simply move the valve drain indoors and get away from the freezing.

All the more reason to involve a competent professional

 

[KULTULZ]

All the more reason to involve a competent professional

Especially if one is considering plumbing in a TET to the COMB Ball & Press Relief Valve outlet (3/8") ...