Bladder type expansion tank

[3fordasho]

It appears that 1000 gallons of pressurized storage requires ~90+ gallons of expansion tank volume. An Amtrol SX-160V plus an SX-40V appears to have worked for some here. Those items will cost $750+ shipped.

I noticed the local menards has 119Gallon Water Worker well tanks on sale. A little research turns up 100psi max pressure, 200F max temp and a precharged pressure that would need to be adjusted (Schrader valve on tank for that). The Amtrols are rated for a slightly higher max temp and this is the only difference I can see. I am quite sure in my planned install the expansion tank will never see 200F.

Any reason not to try the 119G well tank? If the bladder would fail wouldn't it still work as a non-bladder type expansion tank?

 

[Woodman1]

I don't know about the well tank from menards. It seems logical especially if it is really rated at 200 degrees. However from my experience 119 gallons might be a little small for 1000 gallons of storage. I made my own expansion tank from a 150 gallon propane tank. No bladder but it works great!

 

[maple1]

That is something I would try if I had the urge. If you tie it into your system low (say bottom of storage) and use a fairly long pipe run, I doubt it would see anything even anywhere close to your max storage temp. Likely not even approaching hot to the touch.

 

[Bad LP]

My expansion tank has a run of about 35' and I can easily hold my hand on the PEX.

 

[nhtreehouse]

I had two SX-90's on my 1000 gallon system and it was barely enough when precharged to ~8psi. I was getting quite close to 30PSI when fully charging storage, I ended finding another tank, a 110 sized one and with all three tanks working in unison, no issues.

My (3) tanks are plumbed in with 1/2" pex with a run of about 20-25' from the boiler piping. By the time the water gets to the expansion, it's cold enough.

I don't know anything about well-type expansion tanks and how they differ from hydronic tanks. Other than the color of the paint, that is.

Final thought - if you keep an eye out on Craigslist, you can sometimes find tanks on the cheap. Also boiler retailers like Tarm Biomass sometimes have lightly used tanks. I believe I got two of mine from them. The other 90 sized one I found on CL for $50. The guy couldn't get rid of it!

 

[kuribo]

I have 2 sx-110 on my soon to be plumbed 1000 gal storage system. I looked at well tanks too because they are usually cheaper but everyone who knows what they are doing I spoke with said don't do it....