...About those "imaginary" compressor explosions....

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abdywgn said:
and drain the tank on a regular basis. Hmm, I wonder if they remember to do that at work?
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Years ago I worked for a company that built a new shop. The air compressor was installed over a small "room" double entry to stop cold air entry in the winter. The air outlet from the tank had a loop up to stop any moisture getting into the shop air lines. After a while I noticed the compressor would cut in almost immediately. So I mentioned that I thought the compressor needed to be drained. Response was the loop stopped the water, to which I replied "where does the water go?"
This went on a few times, with no solution. So on the Friday of a long weekend, I got a ladder and went up and opened the drain. Tuesday morning I was in the manure heap. All the drywall that had been on the ceiling in that room had gotten soggy with the drained water and fallen down. Had to go up and route a copper line down the wall to allow draining once a week.
 
Righty Tighty said:
Thanks for posting, Del. It blows my mind that so many people are doubtful that compressors can ever explode like this. I've gone 'round and 'round with the guys at work and they always say it'll never happen and that if a tank ever deteriorates to that point, that it'll start with pinhole leaks and gradually fail. I say that's horse puckey. If you're lucky, that's what will happen, but you can't depend on it. And this video proves it.

ALWAYS drain your tank at the end of the day and leave it open to let any condensation that didn't get blown out evaporate. Keep that tank dry and rust-free. There's even some folks who install coolers between the compressor and tank to minimize condensation in the tank, which I plan to do.
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In industry to test vessels and pipelines, they fill with water or water/methanol in freezing conditions. This is then pumped up to a much higher pressure than normal operating pressure. This is usually 5000 to 10000PSI. With a liquid fill, if a failure happens the energy is relieved quickly which vastly reduces the potential for injury. When a gas such as air is pressurized and a containment failure happens, that gas expands rapidly. Severe injury can happen.
I was at a compressor station during a "turn around" which is a scheduled repair. The engine oil.had been drained, engine covers removed and a welder had been doing some work. We went for coffee and came back. I was wor
king on the tailgate of my company truck outside. The welder moved to the other side of the engine and got set up. When he struck an arc, the place blew up. Fortunately the large shop door was open to let it escape. The wall bulged out about 4". I ran in to make sure everyone was OK. Work stopped immediately and an investigation began. What happened was when the oil was drained, the ball valve was left open. The side covers to the crankcase were off. Natural gas entrained in the engine oil travelled back up the drain line into the crankcase, out the sides where the covers were removed and built up around the engine. Now that is what I thought of when compressor blew up was in the description. Been to a couple of others that had blown up or burned. When all the aluminium covers on a Waukesha V12 are melted off and the valve covers are either on the floor around or dripped down through the oil drain holes into the oil sump, that sucker got hot.
 
67Dart273 said:
Occasionally this comes up and at least 3 people are always, "well I've never seen this how often does this happen?"

Answer? I don't know but I'd guess "it only takes once." A friend of mine recently gave me a typical cheap china import that had rusted through the tank. It had NOT exploded, but had rusted through and leaked and he caught it and realized what was going on

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It's not just the compressor you need to be concern about, but also the old tools, hose and attachments. Any compress air bottles or tanks can and should be hydro tested yearly or as designated, as fire extinguishers, dive tanks and other types of holding tanks. I have had hoses (oil soak or pulled from fittings) and seals in tools blow and it is not a pleasure. We have been lucky and I and others are thankful for you bringing this mishap to our attention. Never would of thought a small air tank would blow as yours did.
 
Ron_M said:
Is there anyway to do a tank check at home other than a visual or "wait and see"? Ping test? Is there a life limit on tanks as there is on tires?
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You could drain the pressure and remove the discharge to the tank line and the fitting into the tank. Use a borescope to visually inspect the bottom of the tank. The rusted part will usually be on the bottom and fairly easy to see this way. Most pressure vessels need to be inspected at 10 year intervals like propane tanks. You could then if suspicious, remove the compressor and fill the tank with water. Use a long hose and a hand pump to pressure it up to 200 PSI. Stand behind something in case it does rupture. If it passes that you should be good for a while yet. Just make sure to use water to fill the tank and in the pump. Use a good pressure gauge on the pump so you know what pressure you are at.
 
On code built vessels the weld seams are stress relieved. Then legs are welded on and motor mounts are welded on. Chances are these welds were not stress relieved. So there would be locked up stress in these areas. These stresses can result in cracking due to vibration. The vibrations of running your compressor after completely draining your tank daily may increase the stress level.
If you drain the water out of the tank in the morning and after work there is no need to total drain your tank completely. The other alternative is install a automatic drain. Be proactive inspect the compressor mounts and leg welds for cracking. If your compressor and tank is bolt to the floor place a shock absorbing material between the leg and the floor. If the tank is not a code built air tank then be extra cautious. When not attended shut the compressor off.
 
About 3 years ago after I did my garage over I moved the compressor outside and as of yet I haven't built a shed around it....Its under a tarp and I dont use it much. I drain the tank on a regular basis
Its singe stage with a 60 gallon tank, a Sears unit that has to be a good 35 years old
I looked the other day and I didnt see the tag indicting the tank Is ASME. Im not sure of what pressure its set to shut off at but I think about 125
Now seeing that im old and worry about everything, im concerned about the tank
There is a big plug on one side and I was thinking of removing it and getting one of those probe lights and look inside to see the condition of the tank
Or maybe its time for that new 2 stage I always wanted
 
I have tried to weld up pinholes before. It don't work.(for very long anyway) You seal that one and just hear all the rust popping and cracking around that point (partly due to the overall deterioration that cant be seen, added in with the "heat effected zone" around any weld).
I have however, taken 2 compressors and made 1 from them before and it involved my welding the "motor mount plate" from the compressor with the pinholes to a tank that previously had an "oilless" pump and motor combo that let its smoke out. About 8 years later still so far so good.... the pin holey unit was a wheelbarrow twin tank, "hotdog" style taht is/was gas powered by a 5hp Briggs.... the oilless POS was a typical big box unit but its tank was something like 12 years newer than the tank it replaced.
I use it as a "back up" unit, right now my son has it on a long term "borrow", he mostly uses it to air up a tire now and then.
 
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