Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Has anyone seen this before?

plumber6120 Member Posts: 9
I saw this today and it looked to be one of the old steel compression tanks. But after closer inspection i noticed that the supply and return piping for the boiler and the system branch off of it. It also has a tapping for the make up water and a manual key bleeder on each side. My thoughts are that its a combination expansion/air separation component. or maybe a buffer tank. I didn't see any additional expansion tank anywhere on the system so I imagine that expansion is one purpose it serves. Tried finding it online but had no luck. If anyone has any experience with one of these I would love some more information. I've inuded two pictures. Thanks.


  • Steamhead
    Steamhead Member Posts: 15,983
    Essentially they're using the tank as an air separator as well as an expansion tank. If it's working, I'd leave it alone.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • plumber6120
    plumber6120 Member Posts: 9
    Not sure that it's even working. The system had been drained before my arrival. The contractor I met wants to repipe the existing boiler and add a radiant floor panel for the kitchen. So if that is all possible using the existing boiler(if it can handle the extra load) I will remove it and reconfigure the system for its existing baseboard zone and the additional radiant zone. Have you seen one of these before? I've been working on old hydronic systems in Brooklyn ny for the last six years and have not seen one. And my first day working in northern ny I see this. Just curious to know If this was a common practice years ago in certain parts of the country. Thanks for the quick response by the way.
  • Jamie Hall
    Jamie Hall Member Posts: 21,090
    That's what you get for wandering out into the wilderness! I've not seen one exactly like it -- but it is remarkably like the smaller hydropneumatic tanks which used to be quite common around here to control pressure in well or spring pump systems. The idea was that the thing would be about half full of air and half full of water at normal operating conditions. The main difference I see off hand is that those contraptions had a float valve in them, which would let the air out if the water level got to low -- the air was added every time the well or spring pump ran. The pump pumped directly into it at one end, and the system tapped off of it -- often at the opposite end, so that any air would get stuck in the tank.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Firecontrol933
    Firecontrol933 Member Posts: 73
    Never have seen one, but the concept looks good. I'd leave it because it looks as if it should do a really good job of removing air from the system.
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,279
    I have the literature for that product someplace. It wasn't on the market long. I think it showed up in the '40s.
    Retired and loving it.
  • plumber6120
    plumber6120 Member Posts: 9
    Thanks for all the info. These old hydronic components I come across sometimes make me curious. I'm wondering why it didn't stay on the market long.
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,279
    I suspect it didn't hold the air well.
    Retired and loving it.