Purge Air from Well When Pump Cycles On

[winemaker]

I have a 500 ft well with a Schrader valve on the well head followed by a check valve, pressure switch and galv tank. I assume the Schrader is to allow air into the well line so not to have the weight of a 500 ft column of water sitting on top of the sub pump when the pump is off. But, when the well pump cycles on, where is the air supposed to go? Mine comes out the faucets every time the pump cycles back on. How do I purge the 500 ft column of air so it doesn't enter the home and irrigation supply lines?

 

[Reach4]

I expect that thing that looks like a Schrader valve is snifter valve. It was there, as you thought, to admit air, but only down maybe 10 ft. At that point is a device that I forget the name of, but it should let water out to let the pipe take up several feet of air. If the water pressure at that point is low, that thing lets out more water. This was used with the old style pressure tank that had no diaphragm or bladder.

At this point your action, assuming you now have a diaphragm pressure tank, is to remove the snifter valve or somehow cap it. I don't know if its thread is compatible with a normal valve cap. Also remove the topside checkvalve.

If the pump cycles significantly due to that gadget leaking, you could have that gadget removed. Ideally it will not pass significant water, because there is pressure there after the checkvalve is gone.

Edit: Whoops. I missed the " galv tank" part of your posting. If you wanted to put in a diaphragm pressure tank then you would remove what would become the extra stuff.

 

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[Valveman]

The Schrader valve is usually screwed into the check valve. Either way remove both the check valve and Schrader. Like Reach said, this should keep air from getting into the system. However, if air keeps coming, you will either need to pull the pump up 5-10' and remove the bleeder orifice, or if you are getting a lot of air, the check valve at the pump maybe bad and need replacing.

 

[Craigpump]

Your galv tank should have an air volume control on it. Usually they fall apart or seize up and quit working, that's when the air gets blown through the faucets.

 

[Texas Wellman]

Schraeder valve is doing its job but the avc ( I call it an air release) is stuck and won't release the excess air.

 

[Valveman]

Yep replace the AVC in the tank. I mis-read that it was a bladder tank, sorry.

 

[winemaker]

Thanks so much guys for the education and advice! A defective AVC was the culprit. I really appreciate the responses.