Air compressor tank info.?

[Charlesaf3]

manuals on mine all say throw them away after 15-20 years.

I wouldn't mind if they went slow, but a pressure tank explosion sending shrapnel through the barn is not something I need.

I really wonder how often it happens?

[rhett]

Originally Posted by Charlesaf3

...
but a pressure tank explosion sending shrapnel through the barn is not something I need.

I really wonder how often it happens?

A small air compressor under 200 psi, the most dangerous scenario I can perceive is a busted air hose whipping around slapping you in the head. The weakest point will always fail first, the steel tank is definitely not the weakest point on a shop air compressor.

A Steam Vessel allowed to over pressurize is another story, H2O is breaking down to its elements, Hydrogen Gas is explosive when ignited. Also a steam vessel will contain a substantial amount of water, if a rupture occurs below the water line the escaping water at pressure will have substantial force escaping, possibly launching the vessel. An example of Hydrogen danger would be welding in water in a small enclosed space, Hydrogen Gas will build up, ignite and cause an explosion. Commercial divers are warned of this occupational hazard.

Has anyone ever shot a full rattle can with a BB gun to see what happens, I have and no explosion, just a small hole with a mess.

If the Air Compressor Pressure Switch and Pressure Relief Valve fail and the pump is capable to build up enough pressure for a violent tank failure, I see a problem. But this would be as dangerous, if not more having a brand new tank.

Sheesh, light duty PVC pipe is rated for pressures under 200 psi. Steel is not going to rip apart violently at normal working pressure. Even a loose fitting will not have much velocity at low pressures, unless something like an air cannon was in place allowing pressure to build velocity of the mass propelling it greater distances.

Basically, if an air compressor tank rusts through, the air will escape and the pump will run and run and run, sorry no explosion! Just need to patch or buy a replacement.

[Charlesaf3]

Thats the thing - I can see the case for a pinhole leak, but I've also been around hydraulics that let go suddenly, and that was very impressive. Granted a lot more than th 140 psi or so a compressor runs.

[rhett]

Ok, here is a link of a Air Compressor Explosion. Cause = Oil in tank ignited

Alerts

and here

Air receiver on a compressor explodes - WorkSafe Victoria

[Egon]

Don't most of the small air compressor tanks have a nozzle on one end that they could be inspected internally from?

[ampsucker]

isn't the answer to this simply to make sure the overpressure relief valve is working and properly set? if mean if it pops off at 150 psi, then it's very unlikely that you'll have a serious explosion even if your tank rusts through, right?

our compressor is pretty old, probably circa 70s or 80s. keep the oil changed in the crank and drain the condensate out periodically and that's about all we do.

one dangerous condition i have noticed is a plug of ice freezing in the inlet pipe to the tank. (our tank is outside the shop for safety and space reasons). the compressor will run for a minute or so, then you'll hear a pop as the ice is ejected from the pipe and it bounces off the inside wall of the tank, then the pressure gauage on the tank starts to build like normal. this happens even when the bottom of the tank is drained and i think is due to the design of the inlet pipe allowing just a small amount of moisture to leak down from the pump plumbing. it only happens once or twice a year when the weather conditions are just right. i always keep an eye on it when i turn the pump on the first time in subfreezing temps.

amp

[dfkrug]

Originally Posted by rhett

Basically, if an air compressor tank rusts through, the air will escape and the pump will run and run and run, sorry no explosion! Just need to patch or buy a replacement.

I agree, no explosion. We are not talking 2000-3000psi welding gas or
SCUBA tanks here. Steel is very tough and the failure mode for
a tank with under 200psi in it is not dramatic. I notice that my gas supplier
does not do any pressure tests for my acetylene tank (but he does for
my Ar, Ar/CO2, and O2 tanks) cuz of the low working pressure it is rated
for (a few hundred psi).

My compressor tank is pushing 30 and I have had to replace the pressure
switch once so far.

[Charlesaf3]

question is what happens (and I'm not disagreeing with anyone here, just displaying my ignorance) when the relief is at 150 but there is a rusty place in the steel that goes at 125? I'd guess that's the worst case scenario

[orezok]

Reminds me of a friend of mine who was a mechanic in Louisiana back in the 50's. They had this old compressor that had the old style tanks that had a inspection plate bolted to the end of it. It was located next to the toilet room in an old tin building. Well, the pressure shut off switch was broken, so they would just turn in on for a while to build pressure in the large tank and then shut it off.

Needless to say, one of the workers went to the can and forgot to shut the compressor off. It kept building pressure until it blew off the end plate of the tank. It went through the wall of the toilet, took the toilet out from under the worker, went through the outside wall and buried itself in a large oak tree.

He said it didn't even scratch the worker, but it sure gave him a wake up call.

He said that the plate and toilet were buried so deep in the tree that they never did get it out!

[ampsucker]

i guess i agree with the others that it wouldn't likely be a catastrophic failure at those low pressures. it might make a pretty loud hiss, but i don't think you'd see any shrapnel.

amp