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by RF
(calgary, canada)

How to put a drain valve on air compressor? Hi Bill, I’ve got a compressor that doesn’t have a drain, can you please give me some advice how i could add a drain valve on my compressor? Thanks


RF, it is odd to have a compressor tank without a drain, as every time a compressor runs, it’s pumping water into the tank too. Be good if you would upload a photo of the tank for all to see.

Assuming it is a bona fide air tank that you have, then the process would be, with the tank empty of air completely of course…

  • acquire the tank drain
Air compressor tank drain
Basic air compressor tank drain
  • drill a 1/4-3/8″ hole into the tank at the lowest spot on the tank
  • figure out what the male thread size is on the drain
  • weld a nut of the appropriate size to the exterior of the tank, over the hole (the weld must be pressure resistant up to the tank burst pressure – not a job for an amateur
  • thread the drain into the nut thread using an appropriate sealant

Or, get a compressor tank that is already so equipped and relocated your pump to the new tank.

Good luck. Let us know how it turns out, will you?