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hornluv
09-13-2007, 02:54 PM
Hi everyone,

I'm looking to replace the air tank on my compressor, which is a little 10 gallon deal that I bought used a few months back for $30. When I got it, I noticed that it didn't have a drain plug on the bottom. Well sure enough, just a few minutes ago, it turned on and went up to full pressure (a staggering 94 psi) and when it stopped I heard this kind of wet, airy squeak, like when you stretch the end of a balloon. While I was listening around for the source it suddenly just popped and it sounded like the safety valve blew :eek: Scared the bejesus out of me. Anyway, I've got a nice little hole on the bottom of the tank and a nice rusty puddle on the floor. All the replacement tanks in the MSC Big Book cost more than a new compressor of comparable size. Does anyone know of a more affordable source?

Thanks,
Stuart

speedsport
09-13-2007, 03:38 PM
Did you change your skivvies?

hornluv
09-13-2007, 03:45 PM
:D No need, but I do have a nasty bump on the head from where I hit the ceiling :eek:

Fasttrack
09-13-2007, 03:45 PM
you could try surpluscenter.com

http://www.surpluscenter.com/sort.asp?UID=2007091314352546&catname=air&keyword=ATT1

You might be able to rig something up with those 6.3 gallon over-the-road tanks. They have three ports so you could put a drain plug in and its enamled on the inside so its less likely to rust through.

pcarpenter
09-13-2007, 03:53 PM
Try your local farm supply or even Wal mart for one of the (I think) 10 gallon tire refill type tanks. Bolting up the compressor head (I am assuming its a smallish oilless or even oil filled type) might be a treat...especially if you don't want to weld to it....which really then would require re-hydro testing.

If you don't need portability, the compressor head could mount next to it.

Another option....given that you are not too far away....well...its overkill, but...

A local industrial surplus dealer had a big maybe 60 gallon tank of some sort sitting out the last several times I was there. It had some sort of insulating jacket on it which left me wondering if it had been used for a gas that had to be kept at temp, but that is entirely removable. It appeared to be in very good shape and had the typical ring and feet at the bottom of the tank etc. If you think you are interested, I can get you in touch or would even call about it for you to see if its still around etc.


Paul

Duffy
09-13-2007, 05:14 PM
Has anyone given any thought to using a hot water tank or, better yet, an air cushion tank? I know they are for water, but they are pretty dumb, and are rated to 125 psi and tested to 250 psi. I picked one of the latter up at a yard sale for $15.00. It was hot dip galvanised inside and out and I only had to remove the plastic diaphragm. I've been using it for at least six years at 120 psi and it works a treat.

pcarpenter
09-13-2007, 05:35 PM
A not too old post from Evan shows that he got a bladder tank from the junk yard, stripped the ruptured bladder out and did exactly what you talk about. it was a vertical type and had a built-in mounting for a pump on top which served as the mounting platform for the compressor and motor. Not a bad idea at all....especially for something that only makes 95 or so PSI.

Paul

kendall
09-13-2007, 09:08 PM
had an electric water heater that when I tore it apart had a pressure test tag that claimed 300 psi, After I cut it up I started thinking of possible uses for it.

Ken.

Evan
09-13-2007, 10:38 PM
The bladder water tank I salvaged was practically new. It appeared that it was discarded because of some very foul contamination of the water side of the bladder. There wasn't a trace of rust inside the tank and since it is rated to hold air pressure putting it into air service wasn't even a change in what it was designed to do.

Air receivers don't go boom due to rust out. That's a misconception. When they rust out they fail just like Stuart experienced, at worst. Usually they just develop a pinhole leak. They usual cause of an air receiver explosion is oil accumulation in the tank which ignites when the air becomes hot enough from long use. That produces an oxygen accelerated deflagration that blows out the tank.

Air receivers and propane tanks as well as most similar pressure vessels are made from aluminum killed steel. Such steel is soft and does not propagate cracks at room temperature. The only reports I have ever read of an air receiver failing from air pressure alone were in sub zero conditions when the receiver metal was approaching the ductile/brittle transition temperature.

motomoron
09-13-2007, 10:44 PM
Graingers has a nice selection of replacement tanks, but it's got to be a pretty nice compressor to make it financially worthwhile.

I'd find 4 refrigerant tanks from an HVAC shop. Empty R22 tanks or the like. Weld them up in a nice square frame and braze copper tubing to connect them all. Works fine.

C - ROSS
09-14-2007, 08:53 AM
Evan
I hate to burst your bubble (ha) but I have seen the aftermath of a catastrophic rupture of an air compressor tank. A friend was lucky enough to not be in the shop at the time. When he returned all windows were blown out, small parts bins were tipped over and in general a major mess in his shop. At first he thought that he had been vandalized.

It does happen maybe not very often but it would only take once.

Ross

Evan
09-14-2007, 09:59 AM
Evan
I hate to burst your bubble (ha) but I have seen the aftermath of a catastrophic rupture of an air compressor tank. A friend was lucky enough to not be in the shop at the time. When he returned all windows were blown out, small parts bins were tipped over and in general a major mess in his shop. At first he thought that he had been vandalized.

It does happen maybe not very often but it would only take once.

It can happen but is very uncommon. Your shop could also get hit by a meteorite. I'm not going to worry about all the uncommon ways to get killed. There are plenty of common ways to be concerned with. It's all about acceptable risk. Most people that have a shop don't worry about storing oxy/acetylene equipment in the shop and that poses a much greater risk than an air receiver blowing up due to simple material failure. See if you can find a single documented example of an injury caused by a steel air receiver exploding from simple failure of the vessel.

A.K. Boomer
09-14-2007, 10:11 AM
See if you can find a single documented example of an injury caused by a steel air receiver exploding from simple failure of the vessel.


I thought I recall reading (on this very site) about an upright tank that blew and killed a guy or severly maimed him, all he was doing was going to put air in his tire at a gas station and the entire bottom of the tank blew off taking a small shed with it, it sent the rest of the tank into orbit, the analisis was the tank had held water for many years and had a rot line 4 or 6 inches above the bottom and there was speculation about it being a cold day and perhaps the water froze in the bottom of the tank further weakening it...

Evan
09-14-2007, 10:42 AM
We had a discussion about this once and there was such an incident mentioned. The tank in question was cold enough that it had lost about 50% of it's fracture resistance because it was approaching the ductile/brittle transition temperature.

I will point out that you never see air receivers outside up here.

chipmaker4130
09-14-2007, 11:46 AM
As for a new tank, around here brand new propane tanks between 80 and 200gal sell for less than a dollar per gallon. I use one for supplemental air storage and it works great. You'll need to modify the fittings and possibly add the drain at the low point, but that's no big deal.

Lew Hartswick
09-14-2007, 03:10 PM
Bar B Que propane tanks or what I've been using for close on to 20
years, a freon tank, think it was R12 (its white).
NOTE! As long as you limit the pressure. I have my cutoff set at 90
lbs.
...lew...