Where can a get an old style compression tank

https://qualitytanksinc.com/4574-2/

Great product, fast service.

Add a B&G Airtrol and you're good to go.

The Amtrol Pro has a 7 year warranty, a lined tank. It should last 15- 20 years properly installed and maintained.

If you need to replace tanks every two years, it's not the tank :)

For a compression tank to work as designed you need the Airtrol fittings and ideally a site glass.

Horse and buggy technology

Call Cheney Plumbing in Carbondale, CO. He has an excess of brand new ones, several sizes. Trenton 970-379-4222.

B&G still makes them. You can buy a lifetime supply of bladder tanks for what it will cost you.

Umm. No. More like within $50. But I don't buy B$G branded tanks.

$700! Nuts. I paid under 3.

I got my Airtrol tank fitting new on eBay for $49. And it's not that hard to measure the tank diameter first, read the Airtrol instructions, and then buy the right size for the tank.

I installed mine a year ago with help from the pros here and plumbed it with correctly pitched 3/4" copper to replace the horizontal 1/2" copper that had been installed originally.

Since then it's worked perfectly and we no longer have air in our radiators. And it helps that I learned (also here) to ask our boiler techs not to drain and refill the compression tank as they had been doing annually, which was adding dissolved air to the system.

“For a compression tank to work as designed you need the Airtrol fittings and ideally a site glass.”

Agree, and future techs won’t know what to do with it.

That's how B&G specs it now. IAS /EAS to Airtrol. They don't even sell Airtrol boiler fittings anymore. WM has an air sep built in, I think Peerless too.

With a compression tank you will always have to drain water from the tank at some point. The difference in temperature between the boiler and the tank will always cause air and water to migrate over time even if it is set up properly.

That is why compression tanks have tank drainers.

I had an Amtrol bladder tank in my house for33 years before it needed replacement.

Oversizing the bladder tank causes less pressure rise and reduces the stress on the tank. + bladder tank are a lot smaller for a given system.

I have the water fill valve shut off on my system and should be shut off after filling it and I have not had to drain water from my system in 9 years.

Both sizes of Airtrol fittings and the full line of Internal Air Separators are still available according to Bell and Gossett.

I will eventually join the 21st century and get an oversized bladder tank, like an SX-40V or SX-60V for our two high water volume gravity conversion systems, but I'm waiting until one of our boilers bites the dust so that we can replumb everything all at once.

Meanwhile, for me, the Airtrol was a cheap, quick upgrade from a largely non-functional air management system to one that's maybe 75% (?) efficient (I need one of Paul's sight glasses to verify that number!) The 100% efficient system will have to wait a while longer.

Hello Bob,

I made my purchase decision based on my past experience with an open to air saddle tank that was in place for 33 years previous to this that worked with no issues and no bleeding of the fin tube baseboard.

There is no question my system works and works well, the only time I hear air bubbles is when the coal stoker is fired up for the heating season. My only problem is I do not have cast iron 6 tube radiators to increase my thermal mass to store more heat.

I have not noticed that my Wessels steel compression tank sheds little if any heat. The steel tank is not hot to the touch.

You can also play with this online calculator. You'll need to know your total water volume, min and max water temps, and min and max desired water pressure.

https://www.westank.com/calculator/

For example, in my case we have about 100 gallons water, min temp 65 (for a cold start boiler), max temp 160, 18 psi cold and 22 psi hot. When you input that and press "calculate", you get a recommended compression tank size of 40 gallons, which is what we have.

It also gives you recommended sizes for bladder and diaphragm tanks, which you can ignore if you're planning on using a compression tank. Obviously your variables will depend on your system design, but you should be able to calculate your water volume based on boiler volume, piping volumes, and radiator volumes.

Min and max temps will depend on whether or not your boiler is cold start (minimum), and the balance between your boiler output and your radiation output at a given temperature. For worst-case sizing, you could just assume the the max water temperature will be the upper limit of the boiler setting (eg 180 degrees for a typical high limit aquastat setting).

Pressures are also somewhat subjective. You'll want at least 12 psi minimum. I run ours higher at 18 psi to help keep the air from bubbling out in second-floor radiators. And you don't want the maximum pressure to get near your 30 psi relief valve setting. An allowable pressure rise of 4-5 psi or so will keep you from getting close to that. So in your case you might want to start with a 12 psi minimum and a 17 psi maximum, for example.