Compressor Tank – What Are Large Plugged Holes For?
Visitors have asked a number of questions about compressed air tanks and they are featured on this page.
Doug writes… “I am currently designing a compressor pipe layout for my shop and was wondering what the two large threaded holes are used for?

I have a Jenny model W5B-60 and the outlet for air is a 1/2 inch pipe. I plan on running 1″ copper up and over to my drops but was wondering if I could use one of the larger plugged holes to supply the 1″ supply line?”
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Doug, I only see one plugged hole. If the other one is on the other side, either can be used to plumb to your main from the tank.
You can plumb into any size main from the larger hole with reducing bushings. You just have to make sure that the pressure switch always has access to the tank pressure level so that it “knows” when to turn on the compressor.
Much info is here for you on adding a tank, and strangely enough, if you go to the site map page, you’ll find a link called exactly that. 🙂
For example, you don’t want to ever take an air line feed from hear the bottom of the tank, as that’s where all the water gathers.
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Thanks for your help by: Doug
The other plug (inspection port) is at the bottom on the tank. I will use the top for my supply line. I checked out the add another tank info. Thanks I will add the tank since I have the perfect location high up out of the way.
I also wonder about the inspection port removal? I am trying to unscrew the plug that is in the inspection port. The size wrench needed is a 1 1/4″. I put it on and cannot budge the plug. The tank will start to topple over when pushing down on the wrench. Any suggestions on how to remove the plug?
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Heat, applied with care, should allow you to break the bond between plug and tank body.
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Doug’s comment & another question:
Finally got off the inspection plug. I ended up applying heat but could not loosen plug until I used some long square tubing that I had to use for extra leverage.
A buddy of mine suggested that I get the inside of the tank coated. You can get your old gas tank coated to prevent rust. I was wondering if anybody has done this? it sounds like a good idea. What do you think?
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Doug, I think it would depend on the water and rust resistance of the coating, and the cost of the coating versus the cost of the new tank when the existing one finally rusts through.
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