Compressor tank life expectancy

[cardiffrob]

I managed to bring my old compressor back to life (again) with a new set of electrics. It sits inside a Dexion cupboard at the back of the workshop and behind some engines. The thing is, I was wondering how long I should keep saving it from the scrapyard before the tank finally rots out from the inside and then turns into a grenade. Do they ever let go or am I being paranoid? It must be all of 20 years old now and the water trap clogged up years ago. It would be a major undertaking to get it moved out of position for a borescope.
Any thoughts (Other than "Skinflint!")?

 

[optima21]

I had one that rusted through after 15 years. it wasn't a dramatic explosion, just a tiny pin hole that took several hours to empty at 25 litre reservoir and took me ages to find the reason why it was emptying

 

[Cobbler]

My thoughts would be, if it finally rusted through it would go in pin holes rather than split, so very little danger. Only my idea though, but I think I've seen it some where as well, that's what happens. There must be hundreds of compressors around, used every day that nobody ever gives a thought to, built in the year dot.

EDIT Beaten to it

 

[Barlidge]

I had a little old draper that rusted through, started as a tiny pin hole that gradually got bigger until it was running nearly all the time to keep up. Not sure how old it was a 2nd hand when I got it.

 

[MattF]

The reason some explode has never being explained with any degree of certainty, as I recall, but I believe OSHA once did a report surmising it may be the result of oil combustion, not due to the tank itself. There are documented occurences of people doing pressure tests on them using the compressor itself too, by upping the cut off pressure, then wondering why the whole thing ruptured dramatically. The general consensus with regard to general outcome of rusting in normal use though is that it will merely be a pinhole and leak affair, as Optima' had.

 

[500e]

Robb do you mean you never drain it forget rust, leak, boom what about contamination of air not just water but oil as well

 

[brightspark]

if your that worried turn it upside down and tap it all the way along with a hammer. if-its thin it will dent easily if it -don't theres nothing wrong with it. it would only pinhole anyway if it was thin. a 1- gallon oilcan can take 50 psi before the crimped ends flie out . I tested one to destruction

 

[brightspark]

Robb do you mean you never drain it forget rust, leak, boom what about contamination of air not just water but oil as well

well if theres oil in it it wont go rusty - -one of mine lets some oil in the tank and when I drain it it just comes out a milky sludge and never contaminates the filter or pipes

 

[Maker]

There must be a fair bit of water in that tank if it hasn't been drained for years.

 

[500e]

Saw a big vertical one that went bang 40 years + ago was in a separate shed removed the roof & door, as for the oil you are lucky am looking at a plasma in line filter dryer that has oil\water contamination so bad it wont pass air.
PS
Oil floats on water it mixes when most of the water has blown out of the drain
Torch\tip life is also related to moisture
http://www.achrnews.com/blogs/16-gu...ean-dry-compressed-air-for-air-plasma-cutting

 

[brightspark]

now u- mention it I may go give mine a treat and do-them .-not done them in over a year

 

[rikrobson]

I have an old receiver that is from 1959 according to the plate.

 

[Keith 66]

I had an old Broomwade, it was late 1940s & quite rusty inside, mind you it was also made from 3/8" plate so had a fair bit of reduncancy built in.
I was glad to be shot of it in the end though.

 

[premmington]

I worked in a lorry repair workshop years ago (1983).

Where they had a fatality due to an exploding air receiver.

They had two huge compressors, with separate air receivers.

The receivers were positioned behind a "concrete blast wall".

To go behind the wall, it was workshop policy to empty the tanks and lock off the crane valves with padlocks before entering.

It was the owners son that had been killed.

On my first day of work, me and another new starter were marched over to the blast wall by the owner and told:

"if you even think about going behind the wall with air in the tanks, I will hit you and ring your Mother up and tell her why. If you actually go behind the blast wall with air in the tanks and survive, you will wish you have been killed when I get hold of you".

The owner was a nice chap, I can remember having water fights in the yard with him on hot summer days.

 

[Maker]

I worked in a lorry repair workshop years ago (1983).

Where they had a fatality due to an exploding air receiver.

They had two huge compressors, with separate air receivers.

The receivers were positioned behind a "concrete blast wall".

To go behind the wall, it was workshop policy to empty the tanks and lock off the crane valves with padlocks before entering.

It was the owners son that had been killed.

On my first day of work, me and another new starter were marched over to the blast wall by the owner and told:

"if you even think about going behind the wall with air in the tanks, I will hit you and ring your Mother up and tell her why. If you actually go behind the blast wall with air in the tanks and survive, you will wish you have been killed when I get hold of you".

The owner was a nice chap, I can remember having water fights in the yard with him on hot summer days.

Why was there a need for a blast wall and such a strict policy about going behind it? Was there something about these tanks that made them especially dangerous?

 

[premmington]

They were brand new in-date tanks!

The tank they had an accident with had an auto drain bottom float on it. I am led to believe the tank fitting (and or weld) failed and hit the floor then the owners son.

I do think there is a good argument for where everybody positions air receivers within a workshop.

There is a good reason why insurers insist on in-date tanks. I can never understand why tanks on wheels (portable not stationary tanks) are not subject to the same rules?

 

[rtbcomp]

IIRC there's a relationship between pressure and volume where you don't need a certificate. Something like 250 bar-litres ?

This means you can have a 24 litre tank working at 10 bar without a certificate.

 

[500e]

DG the one that took roof & door went POOOOF as well but it was about a meter in diameter & 8\9 ft high if the roof had hit someone, sheets of galvanized tin

 

[Mr shiney]

I have a 100l and a 160l tank on my system that I test 2 yearly! I have the advantage of being a scuba hydro test station so it's easy for me. They are pumped to test pr sure with water and tested for leaks and expansion. My 160l tank is over 50 years old still passes with flying colours.

 

[Farside]

if your that worried turn it upside down and tap it all the way along with a hammer. if-its thin it will dent easily if it -don't theres nothing wrong with it. it would only pinhole anyway if it was thin. a 1- gallon oilcan can take 50 psi before the crimped ends flie out . I tested one to destruction

Whereas a 205L barrel will only take 25psi of mains water until it's an amusing potato shape.