Well pressure tank question


  #1  
Old 08-03-20, 05:25 AM
T
Member
Thread Starter
Join Date: Aug 2020
Posts: 18
Received 0 Upvotes on 0 Posts
Well pressure tank question

My (new to me) lake place has a well & septic system. The pressure tank is a large, tall old style galvanized tank, not sure if it's air over water, or a bladder or diaphragm system.

About 1/2 way down there is a pressure gauge on the tank. I can watch it cycle from 30 to 50 PSI as water is used and the pump kicks in.

I'm in the habit of shutting off the submersible well pump and relieving system pressure thru a nearby faucet when I leave the place. I did the usual routine yesterday, but as I was opening the faucet, the tank started to bleed air from a fitting just below the pressure gauge. This is not a schrader valve, as best I can tell.

I was looking at the system last weekend as I felt that the pump was running too often -- every time we flushed or ran the water for a few minutes. I examined the pressure switch but made no adjustments.

Any advice? Do I need to re-pressurize the system? If so, how do I do that? Like I said, it's not a schrader valve.

Thanks in advance.

Terry S.
 
  #2  
Old 08-03-20, 08:53 AM
D
Member
Join Date: Jan 2019
Location: Southern Arizona
Posts: 139
Received 9 Upvotes on 8 Posts
Time to find out what the equipment is. Making adjustment to equipment not knowing its operation is not wise.
 
  #3  
Old 08-05-20, 04:13 AM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 4,529
Upvotes: 0
Received 279 Upvotes on 255 Posts
Tru this.

Turn off the pump.
Open a cold-only faucet.
Pump air into the pressure tank until you getto 28 PSI. (You did ssay your system goes from 30 to 50 PSI, right?)
If air comes out the faucet before you get to 28 PSI then close the faucet and continue pumping.
Close the faucet if not already and turn on the pump.Show us some pictures of your equipment. If you have a non-bladder tank (no diaphragm, nothing wrong with that) then you need to repeat the above procedure if you depressurize the system. Also, if you depressurize the system, you may or may not waste a few dozen gallons of water when you (mandatorily) repressurize the system.
 
  #4  
Old 08-10-20, 05:59 AM
T
Member
Thread Starter
Join Date: Aug 2020
Posts: 18
Received 0 Upvotes on 0 Posts
I have no way to add air pressure to the tank. I'd have to pull the top plug and tap in a schrader valve.

Someone suggested just draining the tank and allowing the well pump to refill it, allowing that to build the pressure. Seems to make sense. This coming weekend I'll add in a drain valve on the input port of the tank. Right now I can only drain it thru an adjacent laundry tub faucet that is not low enough to drain the thank completely.
 
  #5  
Old 08-11-20, 08:42 AM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 4,529
Upvotes: 0
Received 279 Upvotes on 255 Posts
A port to add air to a non-bladder pressure tank can be anywehere on the tank at least 6 inches from the outlet to the water system. If the port is not at the top it just becomes a little tricky to say whether or if or when the tank is waterlogged.

If a non-bladder tank is prepressurized in the same manner as a bladder tank, the pump cycling will at least for a few weeks be about the same as for a bladder tank, namely the amount of water occupying the tank will typically range from 2 percent to 33 percent (1/3) of the tank capacity.

It will work if you just empty the non-bladder tank of water and then let the pump refill it. But here the tank performance is much less than optimum. The amount of water occupying the tank will probably range from something like 66% to 77% (2/3 or 6/9 up to 7/9) of the tank capacity as you use water and the pump cycles on and off. The first 66% worth of water will not come out before the pump restarts although in case of power failure that water will come out at low pressure and be usable while you wait for power to be restored.

Meanwhile simply adding air unscientifically or even arbitrarily or haphazardly to a non-bladder tank will forestall or even prevent waterlogging as water slowly absorbs the air over weeks or months. If you don't add enough air then the tank will waterlog sooner or later. If you add too much air the only disadvantage is that air will puff out of a faucet or shower once in awhile.

Usually a non-bladder tank found in a house will be somewhat larger than .the recommended bladder tank size.. In which the roughly 7/9 to 2/3 drawdown in gallons for the non-bladder tank is comparable to the typical 1/3 to near zero drawdown in gallons for the typical bladder tank.
 

Last edited by AllanJ; 08-11-20 at 08:58 AM.
Terry Schwartz voted this post useful.
  #6  
Old 08-11-20, 09:00 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,085
Received 3,979 Upvotes on 3,571 Posts
As those galvanized tanks get older they get pinholes in them. Eventually the pinholes will start to rust. It's fairly easy to unscrew the gauge, install a tee and a schrader valve for air charging.
 
  #7  
Old 08-17-20, 06:00 AM
T
Member
Thread Starter
Join Date: Aug 2020
Posts: 18
Received 0 Upvotes on 0 Posts
Thanks for all the replies. This weekend I drained the tank, and added a drain valve on the input port. I allowed the pump to refill the tank and while it seems things improved, I still feel the pump is running too often. It may not run after every flush, but it will if any other water has been used between flushes.

Per AllanJ's suggestion, I'll find a way to add air to the tank.
 
  #8  
Old 08-17-20, 09:02 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,085
Received 3,979 Upvotes on 3,571 Posts
It's fairly easy to unscrew the gauge, install a tee and a schrader valve for air charging.
Here's a thread with pictures...... well-pressure-tank-cycles-pretty-quickly.html
 
Terry Schwartz voted this post useful.
  #9  
Old 08-17-20, 11:06 AM
T
Member
Thread Starter
Join Date: Aug 2020
Posts: 18
Received 0 Upvotes on 0 Posts
Thanks for that link!

Yep, my system looks just like that one, minus the gate valve on the incoming pipe from the well. Actually I wish I had that.... then I could hook my compressor right to the drain valve just installed.

Digging thru my parts bins last night I found a NOS schrader valve on a brass fitting, not sure what size but it might be 1/8" NPT. Should be about perfect for adapting to the plug on top of the tank. I'm not sure but I don't think my tank has the two unused plugs on the side.
 
  #10  
Old 08-18-20, 08:12 AM
T
Member
Thread Starter
Join Date: Aug 2020
Posts: 18
Received 0 Upvotes on 0 Posts
Anyone care to hazard a guess on the size of this fitting? That's a 1/2" drive recess in the top.
fitting
 
  #11  
Old 08-18-20, 09:30 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,085
Received 3,979 Upvotes on 3,571 Posts
Your google link is private. You can make it public or post here directly..... How-to-insert-pictures.

If you use one of the bung plugs you're going to need at least one and possibly two reducing fittings.
Those plugs could be 1" or 1-1/4".
 
  #12  
Old 08-19-20, 05:04 AM
T
Member
Thread Starter
Join Date: Aug 2020
Posts: 18
Received 0 Upvotes on 0 Posts
Try again....


Plug on top of the tank.... Any clue as to the thread/size? I'm guessing 1" NPT. ??
 
  #13  
Old 08-19-20, 05:11 AM
pugsl's Avatar
Forum Topic Moderator
Join Date: Mar 2008
Location: United States
Posts: 8,161
Received 77 Upvotes on 70 Posts
Take another picture with a quarter, dime or something so we can get a size difference.
 
  #14  
Old 08-19-20, 12:39 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,085
Received 3,979 Upvotes on 3,571 Posts
If it looks like 1" by sight..... it's 3/4".

This video explains it better....... determining pipe size
 
  #15  
Old 08-24-20, 06:19 AM
T
Member
Thread Starter
Join Date: Aug 2020
Posts: 18
Received 0 Upvotes on 0 Posts
Here it is with a scale in the picture. I've got an adapter (shown)


-- 1/4" NPT to 1/2" NPT for the schrader valve. I also have 2 more adapters on the way, 1/4" NPT to 3/4" NPT, and 1/4" NPT to 1" NPT.
One of those should work. I don't want to open the top plug until I have the adapters in hand.
 
  #16  
Old 08-24-20, 11:07 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,085
Received 3,979 Upvotes on 3,571 Posts
Looks like you have it covered. Looks to be 3/4".
You'll need teflon tape and/or pipe thread sealant.
 
  #17  
Old 08-26-20, 08:58 AM
T
Member
Thread Starter
Join Date: Aug 2020
Posts: 18
Received 0 Upvotes on 0 Posts
Thanks. I plan to install the schrader valve this weekend and pressurize the tank. Will update the forum on Monday.
 
  #18  
Old 08-31-20, 06:55 AM
T
Member
Thread Starter
Join Date: Aug 2020
Posts: 18
Received 0 Upvotes on 0 Posts
Friday I installed the Schrader valve using the 3/4" NPT adapter. A little surprised when I unscrewed (with great effort) the plug from the top of the tank. I had bled the system down to what I thought was just a few PSI, but when that plug let loose it blew out of the tank like a bullet and hit the unfinished ceiling above, knocking down dirt and crap and insulation. Scared the hell out of me briefly.

Installed the new unit no problem.



This tank has a pressure gauge and some sort of relief valve mid way down. When the water drops below that gauge, the relief valve gently vents air. Never vents water. So that's as far as I could drain the tank.



I let the pump refill the tank until it stopped venting. Then I put the compressor on the Schrader valve and filled it to 28 PSI.

Result is that I can now flush a toilet at least 4 times before the pump runs -- I consider this a success. (These are not low volume toilets)

I did notice a bit later, when running a sink and a couple appliances that were using water, that the water level must have dropped a bit below the gauge again, as I heard the tank venting air briefly. So I'll keep an eye on that.

Thanks for all the help.
 
  #19  
Old 08-31-20, 12:02 PM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 4,529
Upvotes: 0
Received 279 Upvotes on 255 Posts
The pressure tank is not supposed to vent air. There is a leak (big enough to vent air but not big enough to let water out) at that location or there is a component whose purpose is to automatically add more air to the pressure tank periodically except that other components to make that function work are missing.

The tank venting air means you have to add more air manually more often.
 
  #20  
Old 09-01-20, 06:45 AM
T
Member
Thread Starter
Join Date: Aug 2020
Posts: 18
Received 0 Upvotes on 0 Posts
Well, (pun intended) it turns out you are right, mostly. It is indeed a device to vent air from the tank. It's called an AVC - air volume control. it does vent air to maintain the right size bubble in the tank.

Usually it would be paired with a micronizer - a device that uses the venturi effect to pull air into the tank as water is pumped in. My system has none, as you pointed out.

So yes, I'll probably need to periodically add air manually.
 
  #21  
Old 09-30-20, 03:04 PM
S
Member
Join Date: Sep 2020
Posts: 60
Received 4 Upvotes on 4 Posts
I suspect that's a air admittance valve.

In warm weather you can tell where the water level is by feeling a difference in the tank temperature with the hand.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: