Repairing a discontinued Wellmate/Flexcon AVC

[LLigetfa]

I have one each, (old style, discontinued) Wellmate and Flexcon composite HP tank with the large bung on top. As far as I can tell, unless someone is sitting on NOS (New Old Stock) replacement parts are not available. Both of my tanks have their AVC connected to that large bung. Someone made the mistake of using Teflon tape on the pipe thread and over-tightened it resulting in the tape piling up and cracking the bung.

This cracked AVC is my spare. The other two AVC in service are both clogged up and not releasing air. The first of two clogs more quickly but the second being downstream normally takes care of air that moves forward from the first tank.

Twice a week now I check with a laser temperature gun to determine the water level in the second tank to know how much air to bleed off before the air moves forward into my iron filter. If I don't catch it in time, I can hear a splashing sound come from the iron filter and have to start a slow backwash to purge the air. A regular full-force backwash will drive the media up into the top basket which then prevents adequate flow for a proper backwash.

I took off the warning label and flattened and roughed up the top with coarse sandpaper. I then cut some thick aluminum to the same shape as the top of the bung and will epoxy it in place. I tapped both threaded holes deeper so that I can bottom out two swivel unions which will sandwich the aluminum plate. With the unions, I won't have to worry that the epoxy will prevent their removal since they can stay in place permanently. Having the unions also makes it easy to disassemble which is frequently required because of the high iron content in my well water. The middle picture shows one of those unions.

For good measure, I will also put epoxy on the inside surface of the bung. I chose to use JB Weld Plastic Bonder epoxy as it is formulated for plastic. Time will tell if it holds. I am waiting for Winter to be over so that I can take the tanks outside to pressure wash them and to clean the AVCs with muriatic acid.

 

[Valveman]

Wow! Makes me feel really lucky to live in an area where you just stick a pump in the well and hook the line directly to the house.

 

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[LLigetfa]

What can I say? Iron removal is high maintenance. I could abandon my mud well in hopes of a deeper rock well not having as much iron but at $60 per foot with no way of knowing how deep and how plentiful, this bird-in-the-hand is worth many in the bush. My neighbor went more than 300 feet and then had to hydro-frac to get more than a trickle.

 

[LLigetfa]

Wow! Makes me feel really lucky to live in an area where you just stick a pump in the well and hook the line directly to the house.

I've read that a lot of Texas wells that prefer to/ have to use HP tanks so it boils down to the brand as to whether it is high maintenance. IMHO, most AVC systems are.

 

[Valveman]

Lot of difference in wells in Texas. We have good water in the north. But there is all kinds of different water bearing formations as you go further south. I think in the Houston area they still use HP tanks, for a reason.

 

[LLigetfa]

...they still use HP tanks, for a reason.

Given they are high maintenance, one should not deploy HP tanks without good reason. Even if the AVC were trouble-free, since most HP tanks use bleeder/snifter/check for air charging, those pumps might be starting against very little head in an up-thrust condition.

 

[Valveman]

There are a lot of problems with regular hydro-pneumatic tanks that were solved by diaphragm tanks. The only problem with a diaphragm tank is solved with a Cycle Stop Valve. But when you have iron or sulfur in the water, an HP tank can be the best way to mix air into the water as needed. Like you said, HP tanks are for a reason.

 

[LLigetfa]

Here is a pic of the repaired AVC.