Air Compressor Tank Explodes

[hardtimes]

Hey Tom,
Hm, your post is very good, if for no other reason, from the standpoint of getting lots of guys to think safety where this equipment is concerned !
I'm one of concerned for safety. Do you know if there is a way to tell , from metal tag on tank, what year made ? While you have an interesting tank there and are concerned, I also have , what I think is an unusual tank and I'm concerned. My tank (pictured) has STAMPS on the end where air comes out. It also has a 'pin punched' number on the opposite end, which is: 10234-69 . Here's what gets my atn: 5/32 is punched with a lot of other stampings on the outlet end !!
There is a tag pictured that says Devilbiss Co. and the #s: NO.48451 and TYPE. UAM 15004-3.
Popoff is set for 125 libre pondo !
This looks to be, and I was told that it is/was military equipment. Do these numbers tell how old this rig is ? I got it from a 95 yr old neighbor.

 

[eagle]

A while ago, someone here joked that some are so cautious that they wear both a belt and suspenders just in case... (I thought it was funny!) I would say that use some common sense with your air tank, and age has very little to do with condition. A 2 year old china made tank that's never been drained is much more of a hazard than a 80 year old tank that's been cared for.

 

[pat in Santa Cruz]

To test your air tanks you use water and grease.

plug up everything and fill with water as best you can. Then plug the last hole with a grease fitting. Bring up to pressure with grease.

If the tank pops you just get a lot of water and grease, but no explosion.

For gross details look up how to pressure test a tank. It is out on the net in a bunch of places.

this is how scuba, oxygen, argon and acetylene tanks are tested. A scuba tank is tested to 5/3rds of its working pressure. Thats 5000 psi on a std aluminum 80 cu.ft. tank. If it fails, a bunch of water flows out, no schrapnel, etc. The circumference is measured before and after the test. If it permanently expanded more than 10%, its condemned.

 

[Tom Wesenberg]

Pat, did you mean 1% rather than 10%? I would think 10% would be a junk tank, but I know nothing about SCUBA.

 

[BILL WILLIAMSON]

I once built a "compressor" from a freezer compressor & a surplus oxygen tank, fortunately, it never BLEW UP!!----And I might be tiping with 1 finger, or not hearing frum my left ear!
The compressor inlet also was a good vacuum source for testing vacuum wiper motors.
Bill W.

 

[bettlesr]

When my Dad went into business painting and doing mechanical work in the late '40s, he had a small one lunger with a bleed valve set at around 45psi. To smooth out the pulses for painting, he put a tee in the outlet hose and connected it to a truck tire with no schrader valve. A lot of cars got painted that way until they could afford a new compressor with a tank. Still have the compressor and it still works fine.

 

[MrTube]

Hey Tom,
Hm, your post is very good, if for no other reason, from the standpoint of getting lots of guys to think safety where this equipment is concerned !
I'm one of concerned for safety. Do you know if there is a way to tell , from metal tag on tank, what year made ? While you have an interesting tank there and are concerned, I also have , what I think is an unusual tank and I'm concerned. My tank (pictured) has STAMPS on the end where air comes out. It also has a 'pin punched' number on the opposite end, which is: 10234-69 . Here's what gets my atn: 5/32 is punched with a lot of other stampings on the outlet end !!
There is a tag pictured that says Devilbiss Co. and the #s: NO.48451 and TYPE. UAM 15004-3.
Popoff is set for 125 libre pondo !
This looks to be, and I was told that it is/was military equipment. Do these numbers tell how old this rig is ? I got it from a 95 yr old neighbor.

The patent is from 1930 if it helps.

https://www.google.com/patents/US18...a=X&ei=_7QAVMy9CYLKgwTDuoKwBA&ved=0CB0Q6AEwAA

 

[jimcarl]

If you have a dive shop nearby you might try them. They can do visual inspections on steel scuba tanks and could probably do the same for your compressor tank. They might not want to tell you the tank is ok, but they could probably tell you if it's not!
JimC

 

[hardtimes]

Hey MrTube,
Thanks for that info/site. Hm, 1930, so maybe that accounts for the 5/32 stamping ? Inspected in two years ?
BTW, looking at my compressor pics, can this compressor be 'rebuilt' or is there any way of knowing IF it needs rebuilding ? Seems to build up pressure, but takes long time. I blasted my entire Model A chassis with compressor..took forever. Would hate to get rid of it, as it's like an old friend now. BUT, safety concerns trump other concerns,eh !

 

[MrTube]

Hey MrTube,
Thanks for that info/site. Hm, 1930, so maybe that accounts for the 5/32 stamping ? Inspected in two years ?
BTW, looking at my compressor pics, can this compressor be 'rebuilt' or is there any way of knowing IF it needs rebuilding ? Seems to build up pressure, but takes long time. I blasted my entire Model A chassis with compressor..took forever. Would hate to get rid of it, as it's like an old friend now. BUT, safety concerns trump other concerns,eh !

I'd say it was made in 5/32.

Just because the patent was in 1930 doesn't mean it was made then, could've been before or after by many years. 5/32 sounds reasonable.

EDIT : actually because it says "patent" and not "patent pending" it was obviously made after the patent was approved, but it could be anything from the same day to years after.

 

[Tom Wesenberg]

Hey MrTube,
Thanks for that info/site. Hm, 1930, so maybe that accounts for the 5/32 stamping ? Inspected in two years ?
BTW, looking at my compressor pics, can this compressor be 'rebuilt' or is there any way of knowing IF it needs rebuilding ? Seems to build up pressure, but takes long time. I blasted my entire Model A chassis with compressor..took forever. Would hate to get rid of it, as it's like an old friend now. BUT, safety concerns trump other concerns,eh !

What kind of valves does your compressor have?
Most have disc or reed valves, and I've had reed valves break, which greatly increases the time it take to make pressure. I would remove the head and check the valves. Also check for leaks. They often leak at the fittings or the diaphram of the pressure regulator.

 

[BILL WILLIAMSON]

When my Dad went into business painting and doing mechanical work in the late '40s, he had a small one lunger with a bleed valve set at around 45psi. To smooth out the pulses for painting, he put a tee in the outlet hose and connected it to a truck tire with no schrader valve. A lot of cars got painted that way until they could afford a new compressor with a tank. Still have the compressor and it still works fine.

Now that's a REALLY trick idea, Bettlesr!! A BIG tractor tire would be even better! PO' FOLKS HAVE PO' WAYS
Bill W.

 

[pat in Santa Cruz]

Pat, did you mean 1% rather than 10%? I would think 10% would be a junk tank, but I know nothing about SCUBA.

actually what is done is that the tank is lowered into a water filled chamber, with a burette attached that measures the amount of water displaced as the tank is pressure tested. The tanks will always expand permanently from the test. If, when the pressure is reduced to atmospheric pressure, the water does not retreat to 10% or less of the original reading, the tank is condemned. So its not the diameter, rather the volume of water in the containment tank displaced by the cylinder that must fall within 10%. SCBA tanks (the ones fireman wear) have more stringent requirements as they are filled to 4400 to 5500 psi. They must return to 5% of original volume displaced. When those tanks blow, they can lift a fire engine off the ground.

Prior to a hydro, all tanks must be visually inspected annually. Pits greater than .020 can condemn a tank depending on their location and the metal type of tank. Scuba aluminum tanks are rated at 3000psi; steel tanks are rated from 2200 to as high as 3300 psi so the standards are somewhat different than a 250psi air tank.

 

[Tom Wesenberg]

Here are some more pictures of my small antique compressor. I don't see any patent information, nor do I see a blow off valve, so may have to add that. The compressor cycles on and off at 60 and 80 pounds. This compressor should work well to inflate Model A tires and blow out carb jets.

 

[hardtimes]

Hey Tom,
Thanks ! The only things that I know of a compressor, is what I've found from practical application/use. For instance , does a compressor have piston with rings..do not know, that's why asking should something this old be rebuilt (if has rings) ? Also, do not know if it has reed valves or ? I am familiar with 'reeds', as my harmonicas have reeds !
Thanks for the idea of taking the head off. Hm, does it have a head gasket..I'm guessing that it does..but maybe an O ring tho ?

And , thanks for the leak advice, although I've already located and 'fixed' several.. soapy water method. One pinhole leak near the bottom of tank just inside of the drain valve, right where the water would sit, from not being drained .
Anyway, I developed this 'theory'...that if I plugged up THAT leak with JB weld, that it might/would blow at 125 libre pondo before any of the rest of the tank would give. I feel that this fix and theory will work...kinda like a second safety valve . If I do not give in to urge to increase pressure (I like to sandblast), my plan/theory for safety margin should work,eh ?
I've drained my Grainger 1 horse regularly over the 40 years that I've had it..no rust has ever come out, so doing right by that one I think. It makes some odd noises, but I've worked it to death sand blasting old car stuff since it was new. It's kind of neat to think that this old Devilbiss was built at almost the exact same time as my '30 roadster Both quality American made products !

 

[pat in Santa Cruz]

Tom, that's a really nice old compressor. is it a low RPM type? I love the sound of the old ones...they sort of chunkachunka slowly as they run. The modern high speed diaphragm types (mostly from China) are so loud they hurt my ears and annoy me while they are running. I have an old gas station compressor from the early 50's that runs slow and softly. Its good enough for tires, driving shop tools like die grinders and even small paint jobs. If I need more volume, then I turn on the noise maker which I manifolded into the main tank.

Here are some more pictures of my small antique compressor. I don't see any patent information, nor do I see a blow off valve, so may have to add that. The compressor cycles on and off at 60 and 80 pounds. This compressor should work well to inflate Model A tires and blow out carb jets.

 

[Tom Wesenberg]

If you use a 1 H.P. to sandblast, you must have worked it to death. I've used single stage 2 cylinder Sears compressors up to 3 H.P. to sandblast, and while they get the job done, a person should have at least a 5 H.P. two stage compressor with at least a 60 gallon tank. I bought a 30 gallon tank that had a pin hole in the bottom from the water setting in it. I removed the large end plug to inspect the tank, and it looked perfect except for that one small spot, so I welded a patch about 2" x 4" over the pin hole. It worked fine until the electric motor burned up, which I blame on the fuel saver box the power company installed to turn off the power when demand is high.

Pat, yes, it's a slow runner, which is all I like. The only noise it makes is the sucking of air throught the 8 holes in the grease cap on the head. I would never buy a direct drive oilless compressor. The are short lived and noisey.

 

[hardtimes]

Hey Tom,
Yup, worked it to near death, but it just keeps on working. Granger makes some darn good equipment, and this still working 1hp compressor is a testament to that ! Of course, you have to PM it same as any other hard worked equipment. Darn near looks new yet also ! On the farms that I worked, I was told...take care of that equipment and it will take care of you..whatever that means !

 

[BILL WILLIAMSON]

For 9 years, at my shop, I had a 75 gallon, used, compressor that looked like an old Harley motor. It "lived" under a steel work bench, to save space. NO, I repeat, NO "government" agency EVER came to say, "I'm here to test your compressor & charge you a fee for a permit!!! The Fire Dept. ALWAYS did an annual inspection, but never mentioned the compressor. ALL the dealer shops I worked in ALWAYS had inspections & a framed permit displayed. I don't even remember what "government" agency had charge of the inspections??
Bill W.