919.162120 Regulator valve knob and Drain screw operation

by Handy Woman
(Central Kentucky)

I have a Craftsman 919.162120 oil-free air compressor which was given to me with no operation instructions.


I downloaded an owner's manual but it is woefully lacking in details.

My questions concern the regulator knob and drain valve/screw.. Turning the regulator knob as the instructions directed did not seem to release the pressure for drain down. I know it has to be pulled out to turn, but it didn't relieve the air pressure enough. After 15 minutes, I had to resort to using the safety valve.

Was this the right thing to do or am I not understanding how that regulator works?

Also, the winged drain screw seems to work opposite from "righty-tighty, lefty-loosey". It appears that when the screw is turned clockwise (righty-tighty) it is opening to drain. It seems to, but I would like some verification of the correct direction.

If there is a more detailed manual or video that I could look at, I would also appreciate that link.

Comments for 919.162120 Regulator valve knob and Drain screw operation

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May 30, 2016
Regulator and tank drain down
by: Bill

Per the information on the regulator page, the regulator's job is ONLY to regulate the pressure received by downstream air driven appliances. It is not able to drain the compressor tank.

If you choose not to drain the tank by opening the tank drain due to high pressure in the tank - you can pull on the PRV ring to vent air that way first.

You DO want some air pressure in the tank to help void the water and debris that will be found in the bottom of the typical compressor tank.

I have not made a video of how to drain a compressor tank as it's as simple as opening the tank drain and allowing air, water and debris to escape until the latter two stop exiting then closing the drain so as not to waste the remaining air, and you are back in business.

You do want to do this daily if you are using your air compressor on a daily basis.

May 30, 2016
Video of drain down procedure?
by: Handy Woman

Good information... Thanks! As mentioned in my previous post, while trying to perform a drain down, the regulator knob did not lower the pressure to the required level of 20 lbs, forcing me to use the safety valve outlet. The regulator knob did what it was supposed to in the process of delivering the correct pressure to the air outlet, but I couldn't get the pressure low enough to perform the tank drain procedure... It would be extremely helpful to see a video or even a simple diagram with step by step pictures of the tank drain procedure. The instruction manual has absolutely nothing.

May 29, 2016
919.162120 Regulator valve knob etc.
by: Bill

http://www.about-air-compressors.com/regulators.html

http://www.about-air-compressors.com/compressed-air-videos.html

http://www.about-air-compressors.com/troubleshooting-your-compressor.html

And, you are correct, some tank drains operate opposite from what is expected. If the tank drains and then you close the drain and the air stops leaking, it's working fine.

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