I am looking for a small expansion tank that can relieve the pressure in a potable water recirculation loop for an on demand gas water heater located farther than desirable from the faucets/showers. The total volume in the piping is not very much (figure a max of around 5 gallons or less), so it seems that a smaller than 2 gallon expansion tank could be used.
Anyone know of smaller potable water expansion tanks than the ~2 gallon size?
I believe the hot water (up to about 120 deg F) in the recirculation loop can harm the membrane in potable water expansion tanks. So in this case, the tank should be installed right after the check valve/BFP on the cold supply, but before the recirculation line ties back into the cold feed to the on demand heater, correct?
In other words:
cold feed>check valve or BPF>expansion tank>recirculation loop hot into cold feed>on demand heater
Will potential back flow of heated water into the expansion tank be a concern? What is the max temperature ratings for these potable tanks?
Thanks in advance.
ETA: Street pressure is under 75 pounds
Anyone know of smaller potable water expansion tanks than the ~2 gallon size?
I believe the hot water (up to about 120 deg F) in the recirculation loop can harm the membrane in potable water expansion tanks. So in this case, the tank should be installed right after the check valve/BFP on the cold supply, but before the recirculation line ties back into the cold feed to the on demand heater, correct?
In other words:
cold feed>check valve or BPF>expansion tank>recirculation loop hot into cold feed>on demand heater
Will potential back flow of heated water into the expansion tank be a concern? What is the max temperature ratings for these potable tanks?
Thanks in advance.
ETA: Street pressure is under 75 pounds
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