Bannerman
Well-Known Member
Your well system pressure settings are 40/60 psi. The thermal expansion tank will not be required unless the system pressure exceeds 60 psi. Setting the thermal X tank pre-charge to 60 psi will then result in 0 water in the X tank under normal 40/60 psi conditions, and the maximum available space for water expansion when 60 psi is exceeded.
Reducing the X tank pre-charge will cause water to enter the tank under normal usage conditions, which will reduce available space for expanded water when the system pressure exceeds 60 psi. Setting the pre-charge to only 40 psi will then result in water entering at only 40 psi, so the tank will be substantually filled to capacity @ 60 psi, leaving minimal space remaining to absorb expansion above 60 psi.
While there are frequent discussions about the pressure home piping will tolerate, the weak spot in the system will usually be rubber hoses to connect the clothes washer and similar movable appliances. Due to degradation from drying-out, flexing and pressure variations, it is recommended to replace those hoses every 5-years, but how many homeowners actually do that?
With a 60 psi pre-charge, the thermal expansion tank calculator Reach4 linked in another thread, indicates the minimum thermal X tank required for a 60 gallon WH when raising the water temp from 80℉ to 140℉ @ 60 psi is 1.5 gallons to accept 0.74 gallons expansion.
Since I used a higher 140℉ setting than most people set, and a lower 80℉ incoming temp than the recommended 90℉ to account for higher than average hot water use, your 4.8 gallon tank should be more than sufficient.
http://tools.watts.com/ETP/
Edit: Since your Clack based iron filter incorporates a check-valve, is it actually an AIO or Ozone system? Iron removal filters do not normally utilize a check-valve otherwise.
Reducing the X tank pre-charge will cause water to enter the tank under normal usage conditions, which will reduce available space for expanded water when the system pressure exceeds 60 psi. Setting the pre-charge to only 40 psi will then result in water entering at only 40 psi, so the tank will be substantually filled to capacity @ 60 psi, leaving minimal space remaining to absorb expansion above 60 psi.
While there are frequent discussions about the pressure home piping will tolerate, the weak spot in the system will usually be rubber hoses to connect the clothes washer and similar movable appliances. Due to degradation from drying-out, flexing and pressure variations, it is recommended to replace those hoses every 5-years, but how many homeowners actually do that?
With a 60 psi pre-charge, the thermal expansion tank calculator Reach4 linked in another thread, indicates the minimum thermal X tank required for a 60 gallon WH when raising the water temp from 80℉ to 140℉ @ 60 psi is 1.5 gallons to accept 0.74 gallons expansion.
Since I used a higher 140℉ setting than most people set, and a lower 80℉ incoming temp than the recommended 90℉ to account for higher than average hot water use, your 4.8 gallon tank should be more than sufficient.
http://tools.watts.com/ETP/
Edit: Since your Clack based iron filter incorporates a check-valve, is it actually an AIO or Ozone system? Iron removal filters do not normally utilize a check-valve otherwise.
Last edited: