Page 2 of 2 FirstFirst 12
Results 11 to 18 of 18

Thread: Install a water drain spigot in an air compressor tank

  1. #11
    Join Date
    Jan 2014
    Location
    In the desert
    Posts
    829

    Default

    The tank wall is probably a little thin by itself. You may want to build up a pad of weld, or weld a small plate on where you want to put your drain. Of course making a pressure tight weld on a pressure vessel may be an issue. It would make me pretty nervous.
    *** I always wanted a welding stinger that looked like the north end of a south bound chicken. Often my welds look like somebody pointed the wrong end of a chicken at the joint and squeezed until something came out. Might as well look the part.

  2. #12
    Join Date
    Sep 2015
    Location
    NW Illinois
    Posts
    575

    Default

    Check out the drain valves used on air brake tanks on heavy trucks. They have a cable that runs out to a convenient location so you do not have to crawl under the truck to operate the valve.

    As to the frozen plug: drill out as large as you can. Then take a hacksaw blade and cut 3 or 4 slots just deep enough to see the root of the thread. Use a hammer and chisel to collapse the plug and it comes right out.

  3. #13
    Join Date
    Feb 2012
    Location
    Metcalfe, Ontario, Canada
    Posts
    1,124

    Default

    Quote Originally Posted by Planeman41 View Post
    Thanks for all of the help guys! I like the idea about the remote valve. I may do that. This compressor is an old Sears with a tank mounted horizontally. The pipe type drain plug is mounted on one end a ways up from the bottom of the tank so you have to tip the entire compressor up to pour any water out. I would like to drill the new hole, not through the existing plug, but on the bottom of the actual tank and install that remote valve. Anybody see a problem in that?
    Rust on the inside along the bottom of an old horizontal tank would be my main concern. Putting the drain anywhere other than right at the bottom would seem to be a stupid thing for the manufacturer to do. But if there is rust there already, is it advisable to drill and tap there?

    Putting the question to knowledgeable members, is there any reason not to weld a reinforcing patch on the bottom to accept a plug or drain valve? Assuming, of course, that it's welded on by a more trustworthy welder than me.

    I retired my old compressor because of concern about rust in the horizontal tank. I had no way to see inside, and tapping with a hammer seemed to indicate as much sound steel along the bottom as any where else.

    I bought a new compressor. Should have done my homework first. Huge bloody vertical tank in relation to pump output, and it seems paper thin in comparison with my old tank. Manufacturer says drain it every day and it has to be scrapped in ten years. My old tank was over thirty years old.

  4. #14
    Join Date
    Dec 2004
    Location
    East Coast, USA
    Posts
    6,280

    Default

    What's the typical failure mode of a low pressure (150psi) tank due to rust? If it doesn't split and just starts blowing air through weak points then what is the worst that can really happen?
    Work hard play hard

  5. #15
    Join Date
    Mar 2003
    Posts
    4,226

    Default

    Quote Originally Posted by Planeman41 View Post
    I would like to drill the new hole, not through the existing plug, but on the bottom of the actual tank and install that remote valve. Anybody see a problem in that?
    -Yes. I would NOT recommend welding on a pressure vessel of any kind, unless the wall thickness is significantly oversized. In other words, I might make a small catch tank or manifold system out of welded heavywall pipe, but I would NOT weld anything to the tank itself.

    Replacement tanks are relatively inexpensive, and should come with a more proper bottom drain out of the box. I'd go that route long before I felt the need to weld the original tank.

    Doc.
    Doc's Machine. (Probably not what you expect.)

  6. #16
    Join Date
    Feb 2012
    Location
    Metcalfe, Ontario, Canada
    Posts
    1,124

    Default

    Quote Originally Posted by 3 Phase Lightbulb View Post
    What's the typical failure mode of a low pressure (150psi) tank due to rust? If it doesn't split and just starts blowing air through weak points then what is the worst that can really happen?
    Sometimes they leak and sometimes they blow.

    About two years, I think, since a gentleman just up the valley was killed by the bursting of a small compressor tank.

    If your tank is the type that's going to leak, you don't have to worry. It's the other kind you have to watch out for.

  7. #17
    Join Date
    Oct 2002
    Location
    Saskatoon, Saskatchewan
    Posts
    2,788

    Default

    I must be lucky. My old Kellogg compressor has a small 1/4" copper tube that goes from dead center bottom of the tank up halfway along the side to a valve that's attached to the tank and it certainly looks like it came like this from the factory. Makes draining the tank easy peasy.

  8. #18
    Join Date
    May 2013
    Location
    Lancaster County PA
    Posts
    344

    Default

    Quote Originally Posted by 3 Phase Lightbulb View Post
    What's the typical failure mode of a low pressure (150psi) tank due to rust? If it doesn't split and just starts blowing air through weak points then what is the worst that can really happen?
    I guess if you're lucky it just starts leaking, if unlucky it blows up. Here is a video by Tubalcain that is worthwhile watching, he cuts up an old compressor tank to inspect it. I thought it was very interesting.

    https://www.youtube.com/watch?v=XfLzFR-TOBc

    Dwight

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •