How To Replace Your Old Air Compressor Tank Drain Valve - LIONMAX 1/4'' NPT Brass Tank Drain Valve 👀 

I think mine had a wingnut on it too but it broke off.

Thanks! It's a pretty easy fix. These old compressors will last a long time with a little maintenance.

Yeah that is going to be tough. Those large plugs are in there pretty good too. Let me what you end up doing to get it out?

Same- still searching for video on tips for removing once socket won’t grab the nut. Grr

I am not sure? I will measure mine again and double check what size it is. When you look up air compressor tank drain valves they are all 1/4 inch or 3/8 inch. I bought the 1/4 inch and it fit my tank. If you look you may be able to find some 1/2 drain valves on Amazon too but they are not as common.

I just measured mine and I had the same issue as you did. I looked it up and it says that the 1/4'' NPT actual size is 0.54. So that is the reason our measurement are different. If you have questions about the different sizes you can google "NPT sizes" to get a conversion chart so that you will know what size you actually need. It is called the "National Standard Taper Pipe Threads Size NPT Chart"

I haven't made one yet but I plan on making one soon.

I thought I was going to have to take the whole thing out with a wrench on the big nut. But I got lucky and was able to unscrew drain valve. You can try to unscrew the big nut just make sure you let all of the air out first to release as much pressure as you can.

Have you ever actually removed the large nut ? I’m thinking about removing mine and sticking an endoscope up there to inspect the condition.

Thanks for the sub!