Thread: Exploding compressor.

As AB said initially, there are lots of old compressors still in service and not exploding. Google isn't full of stories of legitimate exploding compressors. If you have managed to catch an exploding compressor on camera then that's a setup any catastrophic failure is most likely a result of exceeding the tanks pressure limit. Have heard of compressors working happily with rusted pin holes in the tank and no explosion. That said, if you are nervous about it put it outside the shed and/or lower the cut out pressure.
Draining regularly is good practice and we all should do it but that wont stop corrosion. Condensation and water will accumulate inside the tank during operation and this alone will cause corrosion, Once corrosion starts it wont stop simply by draining the water. A galvanised tank is the best rust protection but most aren't. Any form of inflexible internal coating like powder coat is likely to crack with continual expansion and contraction of the tank during operation and then any corrosion will be focused on the cracks and is likely proceed faster than otherwise.
In my case I don't use tools requiring more than 90psi so have the compressor cycle between 100 and 125 psi rather than cut out at 150psi as it was designed for.
Tony

I like many others kept forgetting to lay on the floor and undo the drain plug. Eventually managed to get a few brains and came up with this method. The end is a mesh fitting to stop intruders. I usually turn off the compressor when finished and open the ball valve, then close it when next using compressor. Just my way of not getting down on the floor & it opens and closes easily using your foot.

Originally Posted by old1955

I like many others kept forgetting to lay on the floor and undo the drain plug. Eventually managed to get a few brains and came up with this method. The end is a mesh fitting to stop intruders. I usually turn off the compressor when finished and open the ball valve, then close it when next using compressor. Just my way of not getting down on the floor & it opens and closes easily using your foot.

That is basically what I did. I noticed that you have some packing under the foot of the compressor.

This will cause the water to flow to the other end of the compressor. You need to also put some packing under the wheels, unless the manufacturer allowed for this.

Originally Posted by Bohdan

If the compressor has no leaks the pressure will never drop and it won't empty.
On mine I added some plumbing so that I don't have to grovel in the dirt and get sprayed with dirty water every time I drain it.

I had one of those but was also forgetting to open it up often enough

The best option would be one of those auto drains with a float, that are sometimes available on water traps, but there is never enougth room to fit one under a compressor.

I've looked at those and would have fitted one but as my compressor is in an enclosure there is very limited head room above the compressor for air to be lifted up.

BTW As for the electrics it's just a power cord.

Yeps that's all it is.

Originally Posted by woodPixel

It was my thought that manufacturers would apply an enamel or powder coating to the inside. Probably some good reasons why they don't (other than obvious conspiracy theories).

perhaps after doing the evporust thing I could dry it right out and pop a bit of paint in there. Oil paint or something. Swoosh it around a bit. Obviously the plug will need to be removed and the thread protected.
.

There are many air tanks and specialised compressors that have special epoxy liners, galvanised coatings, or best of all use SS tanks. These are expensive and typically used in medical or electronic grade compressed air systems to assist with maintaining air purity.
The epoxy liners are not just any old epoxy but heat tolerant variants baked onto especially prepared bare metal surfaces - if this is not done the paint eventually flakes off the inside of the tank. The Dynair compressor discussed in another thread uses this system. This is something that most DIY folks are not in a position to do themselves.

Just throwing some paint into an old rusty compressor is fraut with problems. Removing all the rust from weld seams etc would be tricky and unless the rust is removed or converted, rust caries with it enough water and oxygen to continue rust even under a coating.

Evaporust applied to a new compressor tanks followed by regular epoxy would be as good as probably a DIY could go. However, there are very few DIY paints or coatings that could withstand the temperature range and that are truly impervious under high pressure. Eventually the water finds its way through micro cracks in the liner or paint and starts corroding the tank again.

The coating also prevents the air from cooling down, so the compressor tank stays hotter for longer which means, micro crack develop and open up further, it rusts faster, and the water stays in the air for longer ending up in air tools and spray guns. Medical grade expose lined systems will usually use an air cooler and drier of some kind.

If a coating is used this also makes an internal safety inspection more difficult.

Originally Posted by artful bodger

What size hole do they fit through?.

8mm I think

I have Toolex 17S compressor and after using it I always open the drain pipe on the bottom of the tank and also open the screw cap on the bottom of the water filter / regulator. Also I release all pressure from the tank with a valve on the top of the tank. Interestingly, the end of the release, little bits of ice are spat out of the valve - it took me a couple of empties to catch one of the icicles to find out what was being spat out. Has anyone else ever seen this ????
Ken

KAJ: compressing gases heat up. Expanding gases cool. So the valving structures get as cold as ice. Funny thing!
When you're venting the tank, stick a thermometer in the air stream, just for fun.

Scuba divers have to learn that truly excess exertion leads to more rapid breathing of increasingly cold/expanded tank air
and chilling of the lungs is most unpleasant.

Originally Posted by Bohdan

That is basically what I did. I noticed that you have some packing under the foot of the compressor.

This will cause the water to flow to the other end of the compressor. You need to also put some packing under the wheels, unless the manufacturer allowed for this.

What appears to be packing is a thin strip of rubber. Thanks for the reply.