Used compressor

[theoldwizard1]

Looking at a used compressor. This is 30+ years old. Likely not used much, but probably stored outside. Pretty certain is does NOT have the original motor, but that is a minor issue.



Is there any way, short of a true "pressure test", to know the condition of the tank ? (I guess it I open the drain valve and a couple of quarts of rusty water comes out, that is not a good sign !)

 

[LopezBart]

Use a borescope to inspect interior of tank through fitting and look for rust.

 

[cgrutt]

Inspect bottom of tank and along welds near the wheel supports. Look for evidence of severe rust (bubbling, flaking, etc). Tap along bottom with small ball peen hammer listen for changes in pitch or if you can feel obvious soft spots.

 

[GeoBruin]

Inspect bottom of tank and along welds near the wheel supports. Look for evidence of severe rust (bubbling, flaking, etc). Tap along bottom with small ball peen hammer listen for changes in pitch or if you can feel obvious soft spots.

Gotta have that special calibrated tap-testing coin though or your tests are worthless! But seriously, It's amazing that the tap test is still used in aerospace composites and the like when all the fancy ultrasonic tests are available, but I suppose it's quick, cheap, non destructive, and effective in the hands of a trained professional.

That said, I'm pretty impressed at how cheap digital ultrasonic thickness gauges are now (I picked one up recently from Amazon Warehouse).