Thermal Expansion Tank

[Intouch]

I have been monitoring the pressure in my house using a pressure guage.
The plumbing is closed system since we have a PRV. After water heater is done heating the pressure reading is 90 psi, our normal pressure is ~45.

My understanding is a thermal expansion tank would help take that pressure so it doesn’t increase in whole plumbing.

1) Should I be concerned about the increased pressure at 90 psi damaging the plumbing or appliances?
2) Would you recommend I have expansion tank installed? My understanding is that it is code to have one for closed system. We don’t currently have any problems with the plumbing except for slight water hammer.

 

[Fitter30]

40 - 80 lbs is normal city water pressure. Recommend a expansion tank with the air charge set to normal pressure 45lb. Tank needs air a hand pump is recommended as not to compromise the bladder. High system water pressure leads to water hammer and extra wear on valves, solenoid valves and hoses.

 

[Sponsor]

 

[John Gayewski]

Yes your need an expansion tank sized for your piping. Generally a 2 gallon is big enough, for a bigger house with more water stored a gal one is necessary.