Air compressor tank info.?

[John White]

The cut out switch went bad on my air compressor the other day. I went to purchase a new one and the fellow said that the one I had, hadnt been made for years and years. And that I should check the date code on the metal tag welded on my tank He said they were good for only twenty years. Another person said they should be re-tested every 5 years. I had three compressors. Two were built in 1957 and one in 1963. I guess a compressor is something we place in a corner and forget it as long as we get air, we dont worry about it. I've got to admit that the compressor gets less attention and service of any piece of equipement I own. I would like (out of courisoty) to know how old some of your compressors are. I cant believe how many years some of the old compressors run. And any advice on testing the tank. I hate throwing away three good tanks (and probably wont). What happens if one goes bad? Will they explode or just start leaking?

 

[Bedlam]

WOW interesting questions I never gave it much thought.Mine is a sears 5 horse and bought in 1980. Knock on wood only had to rel=lace the belt in all this time.Its inside so . but yes I look forward to the tank testing question.
I have a friend who used the standard water well pump switch to regulate on of his.
My question is is this the switch that has the power cord to it?
If so Id imagine you could just mount another one somewhere on the tank..
i couldn't find anything here but its a good site.
Surplus Center - Air Compressors Cylinders Valves Tanks Pumps

Here is the switch if thats the one you are thinking of.usually has a 1/4 inch thread.Perhaps there are other plugs on the tank to mount one
wow not cheap. I am also wondering if it is indeed that switch, if perhaps the diaphragm is crudded up.It happed allot on the water pump switches. the diaphragm and the nipples get crudded up and interfere with it.

 

[Shmudda]

You guys have to remember that any Pressure Vessel (which a Air Compressor Tank is) typically has a certain life span according to the ASME rules and guidelines. Look at your propane tank on your grill, they are all dated for the end of their life too. MOST people, including me, don't adhere to these and run their compressors until you can't anymore.

As for pressure vessels within industries, they get the vessels inspected on a regular basis from either their certified insurance carrier or a company that has the technical personal certified to inspect and certify pressure vessels. This isnt something that would be worthwhile for an $800.00 compressor because the inspection would be much more the value of the machine.

Pressure vessels are something that really shouldn't be taken lightly, but all homeowners and/or farmers do......me included!

Craig

 

[Renze]

What can happen to a compressor tank ?

It may rot on the lower part because of condensate... then it will start to leak above the waterline where humidity and oxygen are best mixed...

It might start blowing from a pinhole, but explode ? dont think so, never heard nor seen so.
I dont care about the age of my tank, i'll hear it whistle when its time to replace.

 

[CurlyDave]

It might start blowing from a pinhole, but explode ? dont think so, never heard nor seen so.

I have worried about this issue for many years. I am not as convinced that corrosion will show up as a single pinhole leak. The cause of the corrosion is condensate in the tank, and because the air pressure is high in the tank, there is lots of oxygen and corrosion is faster than in a non-pressurized tank.

My belief is that in a horizontal tank the corrosion is going be in two lines, at the water-air interface, and that under the right conditions a tank could split along one of these lines. If the tank is vertical, one of the heads could come off.

Either event can be very destructive.

As an engineer, I have read a lot of reports on corrosion based pipeline failure. The pipes have about the same diameter as a compressor tank, so there is some similarity.

 

[tommu56]

John White

It depends on your state regulations.

In Pa most home air tanks are un regulated
The commercial ones have to be inspected regularly and are registered with state.

At work we have ones over 30 years old but they are inspected regularly
This is physical inspection of the tank and the relief valve if its too old it has to be replaced.

tommu

 

[Bird]

I'm curious as to just what is actually done when an air tank is "inspected". I don't recall ever seeing anything in my compressor manuals about a specific lifespan or needing an "inspection" or whatever after a certain length of time. And this morning, I went through the manual for my current compressor and it has lots of information on maintenance; i.e., draining condensation, changing oil, cleaning the air filter, testing the relief valve, adjusting pulley alignment, adjusting belt tension, etc., etc., but nothing about a tank life or inspection. Of course since mine won't be 3 years old until next month, I figure it ought to last the rest of my lifetime.

 

[ultrarunner]

Aside from the physical inspection, there is a electrical device that measures wall thickness.

The compressor/tanks I've put in at the Hospital are required to be registered and permitted to operate.

All have automatic condensate drain lines which is basically a ball valve that rotates 360 degrees at a set time interval.

Not all tanks can be permitted. I have to specify at purchase that I need the ASTM paper work to certify the tank. It costs about $20 more for a certified tank last time I bought one.

 

[John White]

I think I may have open a whole can of worms. My compressors are two stage and as with all two stages they must be rated for 200 lbs as I unddrstand it. One compressor man told me that they are tested 2 1/2 time the rated preassure, another said 1 1/2, I am amazed how many years some of those old Quinceys, Kellogg, Ingorsoll, compressors will last. One compressor man told me that they will last 10 time longer than the ones you buy at Lowes of some farm store. I guess you should drain them every day but I am luckey if I drain mine once a week or month. (bad bad) I think one of them hadndt been drained for years as when I took the plug out alot of surface rust and chips came out. (I purchased all of them used. Probably came out of gas stations in the 60's.) I THINK two of them are pretty good. I was able to get the large bung (plug) out of one and check it with a light it, looked pretty good. The other two couldnt get it out. ) Just looking at the outside doesnt tell ykou much. And as some one said, paying to have it inspected properly would exceed the value of the tank. So if it just sprouts a pin hole, I wont worry too much and just junk it when it leaks.

 

[rhett]

The cut out switch went bad on my air compressor the other day. I went to purchase a new one and...

Just get a replacement that matches Voltage, Cut-In / Cut-Off PSI, fittings can always be adapted to fit.

And any advice on testing the tank.

Not needed, see response made to "Bird"

What happens if one goes bad? Will they explode or just start leaking?

A Steel Low Pressure Vessel containing air, it will just start leaking.

I'm curious as to just what is actually done when an air tank is "inspected".

A Pressure Vessel is filled with water which is not compressible, then placed in a larger water filled container (safety), then a Pressure Test is performed using test values dictated by OSHA for a vessels specifications. Water is used because the only built up back pressure will be between the Pump and Tank.

High Pressure Vessels require these inspections, some Low Pressure Vessels may require certification depending on intended contents.