Air tank rust

[Memmeddu]

I'm thinking the opposite. That if there is a layer of rust in there removing it with chemical treatment is likely to expose the underlying good metal and decay the tank quicker!

Maybe a rust converter approach would be better if you must?

I have looked inside my air tanks with a USB camera. The ABAC one is 20 or so years old and looks fine

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I do also have another good used SIP 200L compressor. It was never drained by PO and only 2 years old. But the rust was visibly worse inside

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(That was standing water in the tank too before I got a new drain cock) Note this is still very much superficial only.

If in doubt, unscrew a bung on the tank and use a cheapie USB endoscope to take a look see.

And make sure and drain your tanks regular!

Your sip looks better than mine

 

[GRW]

My 1972 IR30 compressor had a fair bit of rust flakes in the bottom when I got it. I cleaned it out & sprayed phosphoric inside, but as others said it was probably a waste of time.

As for small Reciever tanks (new, but not too pricey) what about using Lorry braking system air tanks?
I saw Fitters at my last workplace replacing these periodically on trucks, and was told they are a commonly replaced item and consequently relatively cheap to source.

 

[not done it yet]

Pressure test to 20% over pressure if you like but personally I'd just go with it as is

Standard safety test is 50% over Safe Working Pressure.

Don’t skimp. You are dead a long time. It has happened - just look at some youtube acvidents.

Tanks don’t need a complete ring of corrosion. Things break at stress risers. Pressure releascan occur in milliseconds.

Your choice, your risk. Don’t use compressed air to test, either. Use an incompressible liquid - far safer and costs nowt.

 

[Burdekin]

What stress risers are there from the corrosion? What's causing this failure in milliseconds?

 

[not done it yet]

What stress risers are there from the corrosion? What's causing this failure in milliseconds?

By all means bodge your own safety - it’s your risk. But please don‘t try to bodge other’s safety.

There is no place for bodging, where safety is concerned.

 

[Burdekin]

By all means bodge your own safety - it’s your risk. But please don‘t try to bodge other’s safety.

There is no place for bodging, where safety is concerned.

Don't talk rubbish if you don't know what you're talking about. Don't play the safety card, answer the question, what are the stress risers and why would you be trying to pressure test to 1.5 times at home.

Pressure equipment is what I do and doing fitness for service calcs is part of my job.

 

[Morrisman]

Interesting.

 

[Memmeddu]

Interesting.

What is really interesting for me is the round end cracked , which means that it was really paper thin

 

[MetalMonkey]

I've seen that video before - split at the seam, also appears it has been welded on before around the drain port, so it may well have been pinholed and leaking previously.

 

[Memmeddu]

I've seen the part 2 of the video mine doesn't look as thin but it doesn't look better.
Anyway it was paper thin I'm going to scrap the tank,and I'll try to find a 6kg CO2 extinguisher which should be 8mm thick
I can safely weld it , and I can trust it.
8 bar can't make it explode

 

[Dragnet]

That video has made the rounds before. I remember another thread where I think it was variously debunked. On YouTube the idea is to increase the drama for views, not out of a pious and selfless desire to protect others. That's not to say it doesn't happen, but without full awareness of any previous issues with that tank it's impossible to use that anecdotal evidence to help you in your decision.

At bottom, if you're worried, do what makes you not worried, which might be buying a new certified receiver. Others have a different threshold, and it's a big shame that no-one can make choices for us!

 

[brightspark]

What is really interesting for me is the round end cracked , which means that it was really paper thin

wot a load of cobblers

 

[not done it yet]

That video has made the rounds before. I remember another thread where I think it was variously debunked. On YouTube the idea is to increase the drama for views, not out of a pious and selfless desire to protect others. That's not to say it doesn't happen, but without full awareness of any previous issues with that tank it's impossible to use that anecdotal evidence to help you in your decision.

At bottom, if you're worried, do what makes you not worried, which might be buying a new certified receiver. Others have a different threshold, and it's a big shame that no-one can make choices for us!

That is not the only video re exploding compressor receivers. There are plenty if one hunts for them.

Here is a short video (45 seconds) for those that think (or claim) it never happens. Most certainly not a pin-hole leak on this one.

I watched a video recently where a question was asked about electrical cabling rating. Only 75% (of those that should have known) chose the correct answer. 72% of the other watchers, who responded, chose the correct answer. Goes to show that a lot, who claim they are ‘experts’ in the particular subject, aren’t really that clever.

The video is easily found by searching Youtube for ‘compressor receiver failures’ It came up as the first hit. Its title was ‘Air compressor security video of actual explosion’.

 

[Burdekin]

That is not the only video re exploding compressor receivers. There are plenty if one hunts for them.

Here is a short video (45 seconds) for those that think (or claim) it never happens. Most certainly not a pin-hole leak on this one.

I watched a video recently where a question was asked about electrical cabling rating. Only 75% (of those that should have known) chose the correct answer. 72% of the other watchers, who responded, chose the correct answer. Goes to show that a lot, who claim they are ‘experts’ in the particular subject, aren’t really that clever.

The video is easily found by searching Youtube for ‘compressor receiver failures’ It came up as the first hit. Its title was ‘Air compressor security video of actual explosion’.

This is really one of the stupidest posts I’ve read in a long time. You’re clueless about pressure equipment and easily influenced and uneducated on the subject obviously. What were the stress risers that caused this supposedly compressor tank failure?

 

[Burdekin]

By far the most common cause of failure of pressure vessels is over-pressuring so check your relief valves regularly. My compressors are rated at 10bar but most domestic compressors aren't efficient over 8bar so I adjust them down to 8 bar so they aren't in that 8 to 10 bar range working harder than they need to be. I use my compressors for spray painting mainly and I need a constant volume of air at around 2 bar so I could reduce the working pressure of the compressor even lower. Currently my compressors will kick in at 6 bar and I could lower that more for my needs and how I use them. The less stored energy in the pipes and hoses is a good thing as well.

Regularly; drain the tank, check the safety devices, check fittings and replace old hoses. A hose or fitting is a significantly higher chance of failure than the tank and you don't want a hose hitting you. If you keep these all in good working order then they aren't going to mysteriously blow up.

 

[not done it yet]

By far the most common cause of failure of pressure vessels is over-pressuring so check your relief valves regularly. My compressors are rated at 10bar but most domestic compressors aren't efficient over 8bar so I adjust them down to 8 bar so they aren't in that 8 to 10 bar range working harder than they need to be. I use my compressors for spray painting mainly and I need a constant volume of air at around 2 bar so I could reduce the working pressure of the compressor even lower. Currently my compressors will kick in at 6 bar and I could lower that more for my needs and how I use them. The less stored energy in the pipes and hoses is a good thing as well.

Regularly; drain the tank, check the safety devices, check fittings and replace old hoses. A hose or fitting is a significantly higher chance of failure than the tank and you don't want a hose hitting you. If you keep these all in good working order then they aren't going to mysteriously blow up.

Not like the 458,000 Ingersoll-Rand compressors, which were recalled in 2002, that were at risk of catastrophic failure (not just a pin-hole leak). Have a nice day, expert bodger.

I wonder if the chinese manufactured receivers are any better than those recalled ones - but they won’t explode, according to the resident expert (I do wonder of his qualifications, mind). I expect a BSc would trump a few grade C GCSE ‘passes’?

 

[Burdekin]

Not like the 458,000 Ingersoll-Rand compressors, which were recalled in 2002, that were at risk of catastrophic failure (not just a pin-hole leak). Have a nice day, expert bodger.

I wonder if the chinese manufactured receivers are any better than those recalled ones - but they won’t explode, according to the resident expert (I do wonder of his qualifications, mind). I expect a BSc would trump a few grade C GCSE ‘passes’?

Context; sold between 1983 and 1991 there were reports of 11 tank failures (how many exploded? :-) ). So 11 out of 458000 compressors up to 40 years old with no known maintenance history and no one was injured. You’re having a laugh.

That’s right I watched a couple of YouTube videos and did some Googling and now I’m an expert like you. YOU DON’T KNOW WHAT YOU ARE TALKING ABOUT. I actually also have quite a few post grad specific qualifications pertaining to design, inspection and assessing pressure equipment along with 21 years experience.

Still haven’t expanded on what stress risers are. Maybe those Ingersol-Rand tanks were exploding all over the place due to them? :-)

 

[MetalMonkey]

I wonder if the chinese manufactured receivers are any better than those recalled ones

The recall is on small < 3hp machines marketed under several brands - which would suggest they probably are the generic Chinese manufactured units just imported and badged.

I suspect in the land of the lawsuit, it is a smart move to issue a recall on old pressure vessels which have likely seen no inspection or maintenance purely just to cover oneself.
They are only offering to pay return shipping and a $100, so they aren’t that concerned about getting them back.

Anything pressurised has the potential to explode, but the question is how realistic is that to happen.

 

[mike os]

Anything pressurised has the potential to explode, but the question is how realistic is that to happen.

Short answer... very very small ... like 10 in 500k small

 

[brightspark]

you never ever hear of wagon air brake tanks blowing up and look how old they are .water on inside salt and water on the outside