Air Compressor WARNING!

[Industrial Toys]

I TOTALLY agree on the cycling causing fatigue. And of course it's going to fail at or near the weld, and of course any corrossion is going to exasperate this.

 

[pmsmechanic]

Liability is the main reason, I am sure.
Metal fatigue is an issue, but not if the MOE isn't reached. Metal will absorb stretch and retract a LOT, as long as the limits where the metal stretches isn't reached. If you stretch the metal to a point where it starts to stretch and not retract, the chances of failure become really huge. Wrapping a wire around it, (how about a flat tape measure?) to see how far it stretches is and doesn't retract, but with all the different angles that could stretch and not retract (such as around the welded on pipe connections), just the wire really doesn't give the full story. Usually water sitting in the bottom of the tank tends to corrode that area more than the higher regions and that area is where it tends to fail first. Hydro testing (the proper way) has been deemed to be a pretty good indicator. (BTW, my experience, while minimal, was attained in the field of high pressure vessels used in the welding field).
I just hate that such a well executed video is so misleading, and no telling how many people may use that same example as gospel.
David from jax

I appreciate what you say here. it makes sense. A flat tape measure would work but the only ones I know of are my wife's fiberglass for sewing. I don't know if they stretch or not and it's impossible to get an accurate measurement with a standard tape measure.

At first I was going to disagree about the "well executed video" but after thinking about what executed means I have to agree with you. He did an excellent job. He's obviously an intelligent man but I get so turned off by his videos. To the point I don't watch him at all any more. There's just too much repetition and I feel my YouTube time is worth something too. It's really to bad because he does excellent work. End of rant. I'll sleep better tonight!!

 

[Fuddy1952]

In video, guy forgot to show his briefs.

 

[shaeff]

View attachment 685568

There was a fairly involved thread over on Welding Web where a Youngster was intent on repairing an old pin hole rusted compressor tank.
He did weld on it and eventually water pressure test it- but still a Really REALLY bad idea.

Who wants a time Bomb in their shop.

If a tank is to be welded on it should be inspected, and then only welded by an ASME Certified welder and then hydro tested.

:thumbsup:

 

[Industrial Toys]

I like the Stainless idea. But that so goes against everything the whole consumerism culture is about.

 

[Tractor Seabee]

Liability is the main reason, I am sure.
Metal fatigue is an issue, but not if the MOE isn't reached. Metal will absorb stretch and retract a LOT, as long as the limits where the metal stretches isn't reached. If you stretch the metal to a point where it starts to stretch and not retract, the chances of failure become really huge. Wrapping a wire around it, (how about a flat tape measure?) to see how far it stretches is and doesn't retract, but with all the different angles that could stretch and not retract (such as around the welded on pipe connections), just the wire really doesn't give the full story. Usually water sitting in the bottom of the tank tends to corrode that area more than the higher regions and that area is where it tends to fail first. Hydro testing (the proper way) has been deemed to be a pretty good indicator. (BTW, my experience, while minimal, was attained in the field of high pressure vessels used in the welding field).
I just hate that such a well executed video is so misleading, and no telling how many people may use that same example as gospel.
David from jax

The stretch of a cylindrical vessel with variations in pressure would probably be in the micro-meter range. Never be able to measure with a 1/64 increment tape measure plus surface irregularities would probably skew it anyway. Temperature changes would be longitudal. The thin wall of such air vessels make them very vulnerable to interior corrosion especially with the influx of fresh oxygen continually. Once pitting starts it progresses rapidly. Trying to repair small leaks just delays another failure.

Structural failure of an gas container shatters the steel where on a liquid container it just splits till excess pressure is relieved. The most dangerous are those with multi-stage compressors that have capability of far exceeding the pressure rating of the tank; then, failure of a relief valve becomes the culprit. Most single stage compressors top out at around 150 PSI. A certified ASME welder would/should refuse to repair such a thin wall vessel, they are cheap to replace.

Dangerous, yes. Catastrophic failure, rare.

Ron

 

[Industrial Toys]

I always throw my empty or plugged rattle cans in the bon fire. Always surprised that the ends usually blow out and not the sides or seams despite being about as thick as the sheet metal on my HD GMC.

 

[Oldpath05]

15 years ago I took my oxy cutting tanks back for exchange at the weld store, now closed, but the owner was telling me that one of his new customers welded handles on the tanks and brought them in for refill, in short the owner said they're now junk so the customer had to buy new tanks, the weld store owner said he was a little up set, one of them stories thats hard to forget....

 

[5030]

I always throw my empty or plugged rattle cans in the bon fire. Always surprised that the ends usually blow out and not the sides or seams despite being about as thick as the sheet metal on my HD GMC.

I do to actually. I like a good bon fire and save up my rattle cans for that. Best ones are the spray undercoating gans because they use propane for the propellant. The make a huge womp and a big fireball, especially a full one that the nozzle failed on....,.

 

[5030]

15 years ago I took my oxy cutting tanks back for exchange at the weld store, now closed, but the owner was telling me that one of his new customers welded handles on the tanks and brought them in for refill, in short the owner said they're now junk so the customer had to buy new tanks, the weld store owner said he was a little up set, one of them stories thats hard to forget....

Idiots are all hatched.