Rust in compressor tank

[stuckmotor]

I'm getting rusty water when I drain the tank on my air compressor. Should I toss it and buy a new unit?

 

[Industrial Toys]

I have never seen anything other than rusty water in a compressor tank. I'm guessing they are unpainted and untreated inside. Makes you wonder why they wouldn't coat them.

 

[stuckmotor]

This compressor is only a few years old. The water ran clear for the first couple now it's giving me cause for concern. Perhaps a better question would be if the tank fails will it shoot across the room or just spray water out of the rupture.

 

[JimRB]

It will just hiss, at least my pancake tank did.

 

[stuckmotor]

I can live with a hiss, even a rusty one. Here's my next rewording of my question, does anyone know of person or property being injured by a ruptire of an air tank CAUSED BY RUST?

 

[Dave M7040]

Watch this youtube video of actual explosion and decide for yourself if you want to accept the risk.
Air compressor explosion safety video footage of actual explosion - YouTube

Dave M7040

 

[Ed of all trades]

I have seen many tanks start to leak but never do more than loose air slowly. Ed

 

[stuckmotor]

Watch this youtube video of actual explosion and decide for yourself if you want to accept the risk.
Air compressor explosion safety video footage of actual explosion - YouTube
Dave M7040

Dave,
Thanks for the link. I can't watch a video until I get home where I have unlimited internet. Now I'm on a portable hot spot that's low on minutes. Was the explosion caused by rust?

 

[TemporaryKubotaOwnerMark]

Was the explosion caused by rust?

What actually caused the failure really cannot be determined by that video. The uploader says it was rust, but that might not be the case.

It could have been that the regulator failed and over-pressurized the tank. Looks like the seams failed, and there is a lot of rust inside. Did it fail from rust while in normal use? Or was it over-pressurized? No way to know.

The narration is at the first, for the most part. The explosion happens at the one minute, thirty second mark, and there's nothing useful or interesting before that other than the uploaders opinion that the cause was rust. That's followed by another minute or so of people dancing around wondering what happened, and then at about two minutes, thirty seconds or so there are some pictures of the compressor which are of interest.

I don't get rusty water out of mine, and it's more than 20 years old. I get plenty of oily water, though.


This video is really interesting.

Why You Need to Drain Your Air Compressor - Vlog - YouTube

 

[ray66v]

The tank on my compressor has yielded rust colored water, since it was new in 1984.

I've worked around air compressors my whole life, and as Industrial Toys said, I never saw anything other than rust colored water coming out of one.

It's as common as black oil in a diesel.

 

[George2615]

Your compressor tank should be blown down daily or you can add an automatic blow down device. I had a 60 gallon compressor that rusted out the bottom of the tank. The rust created pinholes that leaked air. It took 30 years for that to happen. I sold the motor & compressor to a friend of mine who had a good tank but bad compressor and I upgraded to an 80 gallon compressor for the garage.

 

[Gary Fowler]

Absolutely no way that rust contributed to the failure in that video. Both end caps were blown off, seam split from top to bottom. That was a highly over pressurized tank possibly caused by a failed pressure regulator but also the safety relief valve must have also been frozen up or it would have popped way before the tank exploded.
Lots of lack of maintenance there for that to have happened AND also possibly some bad welding on the seams for both welds on the caps to have failed.
I agree with most of the posts here that a rusted out tank would be at the bottom and pin hole leaks would occur first and there would be no catastrophic release of energy from a rusted out tank.
Rusty water is the norm for drain water. The tanks are not coated inside, at least on all I have seen, so rust is inevitable. An oil free compressor will probable see more rust than one with an oil crankcase which releases a bit of oil into the tank during compression.
I have been using my Craftsman compressor since 1985 and have to admit that I don't drain it daily. Each time I do drain it, I get at least a cup of rusty water from it. I recently installed a 90 ell and a ball valve on it to make it easier to drain but I still don't drain it daily even though I guess it would be best. It is just too hard to get down on hands and knees now that I have passed 67 years of age.

 

[check]

I'm going out to check on my compressor right now!

 

[stuckmotor]

It's as common as black oil in a diesel.

There's the answer to a question I hadn't thought to ask. My present MF is my first diesel and I've noticed the oil is back.

 

[Industrial Toys]

My Cushman mower with a 56 hp Kubota Diesel (non turbo) is the only Diesel I have ever seen where the oil stays clean, not black. And I don't know why.

I once went to see a customer, and found the man with a broken arm in a cast. Turns out it was from a failed galvanized steel garden sprayer. I had just put a schrader valve on my similar garden sprayer thinking this was a great idea. I rethought that really quickly.

 

[ray66v]

Diesel oil is specially designed to collect, and suspend the carbon that ends up in the crankcase.

That way, when you change it, it does not accumulate in the crank case.

Perhaps there are pollution controls, or other technology on newer diesels that helps prevent this. But, normally, if your oil is not turning black, it's not doing it's job.

 

[ray66v]

I have seen a few rusted out air compressor tanks, they developed small pin holes.

No catastrophic failures.

With a stationary compressor, there is going to be one spot that is lowest. And the water is of course, going to sit there. That is not going to weaken the entire tank, if you drain it with any frequency.

While any failure of a pressure vessel, has the potential of being dramatic, explosive failure doesn't seem to be common. And, like much of what is posted on the internet, you have to wonder how much of it is real, and how much of it is a setup.

 

[dickfoster]

Watch this youtube video of actual explosion and decide for yourself if you want to accept the risk.
Air compressor explosion safety video footage of actual explosion - YouTube

Dave M7040

You should see what a scuba tank at 3500 PSI can do. I saw bubbles when filling one of those once, so I shut the compressor down and ran like h e l l.

 

[dickfoster]

I can tell you what one of those can do. It can punch through a cinderblock wall and travel for a half mile before punching through another wood frame construction wall (covered with stucco) and embedding itself in the side of a truck.

Oh, and it can kill you, too.

So now you know why I ran like h e l l when I saw the pinhole leak bubbling air from the side of the tank. I returned about an hour later when I felt it was safe, condemned that cylinder and resumed my filling chores.