Expansion tank size for 500G tank

[MrEd]

Hi all.

Looks like my SX-160V that I ordered from pexsupply is never going to come, and I need to get my 500G storage on-line. I planned on buying the sx-160v so that down the road if I upgraded to 1000G I would be all set, but now I need to ordered a smaller tank that is matched to my 500G that I have.

My Solo 60 and oil burner already have expansion tanks, sized for them.

Using a simple 4% expansion factor, which seems to be a safe number to use, I come up with 20 gallons.

Is that the max gallons, or tank acceptance gallons I should be matching when looking at what to buy?

Would 2 of these work: http://www.pexsupply.com/product_dtl.asp?pID=4183&brand=Amtrol&cID=277

Thanks.

 

[taxidermist]

I have 1000 gal storage and Dave @ cozyheat.net sold me 2 Flexcon sxt 110 62 gal each

 

[jebatty]

Acceptance volume is what you are looking at.

 

[DenaliChuck]

page 8 gives instructions on sizing an expansion tank

(broken link removed to http://www.amtrol.com/pdf/extrolbrochure.pdf)

 

[Kipstr]

I have 500 gal. storage started with SX60 it worked. I got the temp up to about 175, psi at cold (60 F) was 10 psi and hot around 22 psi. So I call Amtrol and said I shoud have SX90, so I add SX40 for a total of 100. Last night befor I fired storage temp was 135 at 15-18 psi I got the tank temp up to 180 top and about 170 off the bottom, the psi was 22 psi. I think it's working OK

 

[barnartist]

I have had 500 gal storage, but am adding my secong 500 gal for a total of 1000+Eko water and system water. While operating with the 500, I only had 20 gal X tank, and it worked well as long as I cycled 50 degrees or so. But, as I add my second tank it dawned on me that I have some air that is trapped at the top of my tanks, because my tank inlets at the top are not at the very top of the tank. They are about 1' down from the very top of the tank (s). (also it should be noted my tanks are vertically standing) I think I gain some expansion from this and it help some. I have heard that you can use and old water heater tank filled with air for this in the same manner.