Well Tank Air Volume Control...

[generator12]

I've got a submersible well pump working into a WellMate 40 gallon tank. It's a non-diaphragm type - Model no. SP-9. Cut in pressure is 40 PSI; shut-off is 60 PSI. There's an air volume control on the side, about 15 inches from the floor. (Pic attached) The tank is about five years old; the pump three years old with new piping up to the wellhead.

The issue is that I'm getting air bursting from cold water outlets whenever there has been significant water draw, such as a lawn hose or the softener regenerating. The warm water, which is all softened and - of course - heated doesn't display a lot of this, but there is some air there also. This doesn't occur with normal day-to-day use, just when I'm drawing water outside the house, or after the softener has regenerated.

I figure that I've got either (or both) of two situations:

1. My pump is outrunning the water source under high draw, and It's pushing air up the line with the water.
2. The air volume control isn't venting reliably when the tank level is low. (I believe this is a float actuated valve, apparently with an orifice to limit its output.)

My immediate question is whether the operation of the air volume control is adjustable - there appears to be a slot on the plug in the body of it for a screwdriver - and whether this is relevant.

Anybody have experience with this?

 

[Bob_VT]

Re: Well Tank Air Volume Control...

Ahhh you use a water softener ......... I would check the check valve to the well. Over years it may have accumulated crap and is flowing back making you loose initial fill/pressure.

I had to replace my well pump and I had a similar problem (yep 2 problems at once) and the check valve was really the annoying one.

 

[Georgesalmon]

Re: Well Tank Air Volume Control...

Shut the pump off electrically and run all the water (and air) out of the tank. There is usually a valve with a hose thread on it by the bottom of the tank use that. When all the water and air is out of the tank shut the valve and turn the pump back on. There will be enough air in the tank to compress and work OK. See how long it takes for the problem to come back.

The air volume control is not working. All it does is keep the air in the tank at a set level and vent it when it get to low. Float is stuck or opening corroded shut. No adj I know of. Replace it.

All the check valves I ever installed were either built into the top of the pump or threaded on to the top of the pump. You will most likely have to pull the pump to find it. If the check valve is leaking back and the pump is under water I don't know where air would come from. Usually a faulty check valve is recognized by the pump starting and stopping when not using water.

 

[rbh]

Re: Well Tank Air Volume Control...

Drain all the water from the tank, refresh the air preasure as I bet there is not much of an air charge left, this happens in tanks with no bladder, the water over time pulls the air charge out with it and you get the spitting at the faucet.

Can your pump keep up with the max draw on it? that pulls all the water out of the tank as well.

 

[Tim Frank]

Re: Well Tank Air Volume Control...

the way that i read the OP's post is that there is a LOT of air being discharged. That does not suggest to me that this is an A/V control issue.
The high draw makes the most sense....and if the check valve is not holding, there may be air drawn back through the A/V control as Bob thought.

 

[generator12]

Re: Well Tank Air Volume Control...

Thanks guys. I believe the check valve is okay as the tank holds pressure when no water is being drawn. Also, the draw-down appears normal/acceptable, as it takes a few minutes for the pump to cycle with a medium water draw in the house.

 

[Tim Frank]

Re: Well Tank Air Volume Control...

I am not sure how you would verify your #1 thought, a well capacity issue.
Only thing I can think of would be to put a short length of "see-through" pipe in-line, just before the pressure tank.

There must be an easier way though.

My water source is a lake, so this is not on my radar screen.

 

[Boomyal]

Re: Well Tank Air Volume Control...

If I read you right you have a system whereby when the well pump shuts off a section of the dropline in the well evacuates and fills with air (I call it an air charger system). When the pump turns on it pushes the air up into the non bladder tank. If so, once the air level in the tank reaches a certain level the device on the side of the pressure tank is supposed to relieve the excess air. That airbleed valve is a constant source of problems.

The real solution is to get a bladder tank and remove the evacuation valve on the drop line. It was a good sounding solution to the normal depletion of air charge in a non bladder tank, that is a constant PITA.

 

[generator12]

Re: Well Tank Air Volume Control...

Epilogue:

"The air volume control is not working. All it does is keep the air in the tank at a set level and vent it when it get to low. Float is stuck or opening corroded shut. No adj I know of. Replace it."


He had it right! Replaced the AVC today and found the original one so gummed up that I'm certain it hadn't opened for quite some time. Essentially, my tank discharged all the air from the pump riser into the house plumbing. I've only operated the system for a few hours as I write this, but I don't expect to see those outsized bursts of air again. This valve was REALLY bad.

Again, thanks guys, for your time and attention.

 

[Boomyal]

Re: Well Tank Air Volume Control...

,,,,, found the original one so gummed up that I'm certain it hadn't opened for quite some time. ......

Read " ......That airbleed valve is a constant source of problems.

The real solution is to get a bladder tank and remove the evacuation valve on the drop line. It was a good sounding solution to the normal depletion of air charge in a non bladder tank, that is a constant PITA."

Disable the evacuation valve and get a bladder tank or you will be soon revisiting this same debacle.