How do I stop my compressor tank from rusting ?

[Wilson]

[Andy Dingley]

A cheaper alternative is to replace the original drain valve with a length of pipe to a valve mounted somewhere convenient on the upper side of the compressor.

If, like many people, your compressor is pushed away under a bench or acoustic cover, this can make the difference between draining the tank whenever you switch off, or never draining it at all. it can also help avoid the "leaky puppy" effect on the workshop floor.

[Jim Wilson]

Maybe not much cheaper, though, if at all. The Harbor Freight automatic drain kits were still right at $10 US last I checked.

Cheers,

Jim

[Andy Dingley]

I'll see your Harbour Freight "complicated pneumatic device for only $10" and raise you my "lifetime's scrapbox of assorted plumbing fittings".

Do I hear any advance ?

Do I hear "truck breakers yard, and a real automatic water-actuated compressed air brake reservoir drain valve ?"

[Jim Wilson]

Har! I happen to have one of them there complicated devices [*] in my (prolly shorter-lifetime) scrapbox of assorted plumbing fittings! So, there, they're free! (G)

Interesting, that idea. What is it, and how's it work? I love to put a tossed-out part back into good service somewhere.

Jim

[*] Which item, by the way, reminds me of an issue. The "complicated pneumatic devices" don't work so well on a negligent friend's compressor tank what went undrained for seven years. Even after emptying, his tank still spit mud -- I.e., oxidized receiver innards -- and clogged up the auto-drainer-valve works for weeks. Eventually, we just gave up on it and stuck in a ball valve instead. He tells me he's going to replace that compressor....

[Lawrence Wasserman]

Speaking from 27 years experience as a truck and heavy equipment and supervisor, I'd have to say that they don't work all that well and I wouldn't bother with one that came form a scrap yard. Every air brake truck made still has a manual drain valve installed on the air tanks.

[Jim Wilson]

Ah, well. But how are they *supposed* to work? The actuator, I mean.

Thanks,

Jim

[Andy Dingley]

They work by voodoo. Or something. Had them to pieces when I was a kid, never really worked it out.

I think it relies on a diaphram with a balanced presure on each side. There's a pinhole leak (one on each side ?), and if the pinhole fills with water then it stops being a leak, the pressure on one side increases and the diaphram deflects, triggering the drain valve.

They work fine when they work, but I think they're touchy about air that's not clean, or has rust particles in it from the tank.

[George Gibeau]

[mnterpfan]

Can you please elaborate on this? I'm having trouble understanding how the water is released when it is higher than the base of the tank. I'm not trying to be a smarta$$. (That comes naturally) I have seen compressors with strange pipes connected and was wondering what they did.

Thanks.

ET

[Andy Dingley]

Doesn't matter - so long as the connection to the tank is at the bottom of the tank, then you can hang as much pipework on the outlet as you like. After all, there's 130psi of air in there to blow it out (that's a couple of hundred feet straight up).

[Jim Wilson]

Thanks, George. Um, that's my page. (G)

Cheers!

Jim

[mnterpfan]

Oh, okay. I was assuming that the pressure had been released before draining the tank. Thanks.