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Discussion Starter · #1 ·
I have been reading so much about well pressure tanks that it has probably caused more brain damage than good. Some sites say (1) drain all water (via compressor or whatever) and there should be at least 7psi of air; or (2) air pressure should be 2 lbs below cut-in but they don't say WHEN this is valid (e.g. with system off and pressure relieved or some other combination); (3) there should be 20psi when no water pressure; (4) so many others that I have no confidence in what I am doing - but, I am confident that not all of these guidelines are compatible with each other.

So, the best that I can do is describe my situation and someone can hopefully shed some light on whether or not this is right.

The well is only used for the watering system; it is about 4 years old; the pump is underground, the tank is in the garage. It is clean and relatively new as far as I am concerned.

About 6 weeks ago, I noticed that when the lawn was getting watered that the sprays sprayed full pressure only to quickly die down to nothing for a few moments and then increase again to full pressure, etc. Essentially, the pump was cycling rapidly. Sadly, this was going on twice a week for a bout 6 weeks (maybe longer) for about 3 hours each time.

Anyway. I checked the PSI. Flat 0. Nothing. Turned off system. Tank, by knocking on it, seemed clearly full of water. Impossible even using all of my weight on a bicycle pump to put any air pressure in. Finally, I grew a little bit of a brain and opened the valve to a hose connected to the system. Then, suddenly after a strange sound, I was able to put pressure in the system and displace the water without any issue. Closed the valve, got the compressor and proceeded to put 20psi in the tank (that number was told to me by some random plumber).

Now, the system seems to be working pretty well. But not sure if it is quite right. Pressure without water in the tank is down to 10psi, but this may just be after settling. Cut-in pressure is 44psi. So, if there is 80psi on the main gauge, the air pressure exceeds 50psi, but it certainly is NEVER 42 psi under any conditions (that is the 2 below cut-in pressure that so many people love to talk about which has no meaning to me at all because it HAS to be a moving target).

Basically, I'm just trying to figure out if this is right, wrong, or if something is broken.

I really don't understand the 2 blow cut-in pressure because no site I have found says what the initial condition for this measurement actually is: is it when the tank JUST cut-in and you stop the system and measure (very difficult because it is so sudden); is it when there is no water pressure in the system and it is turned off; is it when the pump just cuts out (at about 80 psi); I can't make heads or tails of this but basic physics tells me that it is a moving target based on the current pressure in the system which is totally unpredictable except that cut-in is at 44 and cut-out is about 80. So, the whole Internet basically makes it sound like regardless of the pressure that is already there, the air psi should be 42 if it is correct. Hello??

Anywho, I appreciate your help and I apologize if this came off as a rant.
 

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Naildriver
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From your description you may have a blown bladder in the tank. BUT, let's start anew just to make sure. Turn off the well pump. Drain the tank completely. No need for a compressor, etc, just let gravity do the work. You'll need to open a faucet to allow it to drain completely.

THEN take a pressure reading at the valve on top with a reliable tire gauge. If you know the cut in pressure of your tank, replicate it in the tank using a compressor, just like filling up a tire, only short spurts at a time, checking after each spurt. Bring that pressure to 2 lbs less than that cut in pressure.

THEN energize the pump and check your system. Hopefully it will solve the problem. Let us know.
 

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Let me see if I can help with this.

Let's say I bought a new pressure switch and a new tank.
The pressure switch paper work reads that it was factory set to switch on at 44 psi and switch off at 80 psi. This is telling me to check the pressure tank pressure. It will need to be adjusted to 42 psi and that can be done before I install it or after installation but before the well pump is turned on.

Now that your tank seems to be completely full of water it is said to be water logged because of 2 things you mentioned. 1) the pump is rapid cycling and 2) you couldn't put air into the tank because it is completely full of water and is basically a 80 psi hydraulic unit.

It's time to purchase a new tank.

Don't attempt to be too exact when adjusting the tank pressure to the stated 2 psi below cut in pressure with your gauge. It will not read the same as the factory bench test gauge that was used to set the switch pressure I guarantee and could be off as much as 3 percent plus and between the 2 gauges could be off as much as 5 percent. Just get-er close and be happy.

Please do not ( screw around ) with the pressure switch adjustment as so many are inclined to do.
 

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It all depends on the type of pressure tank you have.
Some tanks have a bladder. Some tanks do not. If you have a small tank( about the size of a 20 pound propane cylinder) then you most likely have a bladder tank.
If you have a large tank like a water heater than you most likely have a non bladder water over air tank.

Once we determine the type of tank we can give the proper advice as it is very different for the two types.

Post some pictures of your system. That will help us determine what you have.
 

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Discussion Starter · #5 ·
Thank you for your response. I, unfortunately, forgot to take a picture of the system before I left the house today. I can have someone do this for me tomorrow perhaps. I will be out of town for a little while. That said, I did follow your instructions and this has brought a lot more clarity. My noob assumption regarding "bladder tanks" was that the AIR went into the bladder and displaced the WATER which went into the tank around the bladder. As I have realized this is not the case, things make a little more sense now.

This is not a water-heater sized tank, just a blue tank about 14-18" tall and a couple feet wide with a schrader valve on the top near the side. The pump is supposed to cut-in at 40 and out at 60 (I think I had a typo on this earlier). According to the gauge, it actually cuts in at 44.

So, as per your instructions, I let the water exhaust itself and then proceeded to put about 41-42 lbs of air in and then turned the system on and ran the highest-volume watering zone and it performed much better than it did before. I will see over the next week if it degrades and I'll re-check the pressure.

As a side note: when I finally first started messing with this yesterday, there was zero air escaping through the air valve when pushing the pin. On the up-side, it seemed dry - no water came out either. However, I am skeptical that the bladder isn't ruptured considering that this was running for a couple of months with evidently no air pressure and, I would imagine, that this would have put quite a bit of strain on the bladder.

Again, I appreciate your help hugely. I at least have a better understanding of the system and am less worried about blowing things up.
 

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It sounds like you have a bladder tank for sure. 40 psi would normally be too much. With the pump shut off and the pressure drained down to no water flow you need the tank to be set at 2 psi less than the turn on pressure of the pump. Normal house systems run 20-40 or 30-50 on-off pressures. Those would bet at 18 or 28 psi.

On the up-side, it seemed dry - no water came out either
That is good. The bladder is probably fine. If the valve is bad that could be where the air leaked out. Put a bit of soapy water on the end of the valve and see if it bubbles.
 

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Discussion Starter · #7 ·
Having had a week go by, I came back to town and drained the water pressure and checked the air pressure. Still holding at about 40psi and seems to be running good. Air pressure doesn't seem to have dropped a bit. I am at a loss as to how all pressure had been completely lost before. As I mentioned, this is a four year old tank and it is indoor. My next-door neighbor has had his for 8 years and has not had a single problem.

Someone mentioned above to not mess with the actual cut-in/out pressure settings: definitely not. I only observed when it cuts in via the pressure gauge: 42 psi and out at 60 psi. Not sure why this is set higher than what most seem to consider typical for a residential unit, but considering the vast volumes of water it has to serve for hours on end during the summer, it makes some sense. 5 zones, 50 minutes each and the zones aren't small.

I don't know why I couldn't put air pressure in initially. It was as though someone was physically blocking the inlet even though the pin in the valve moved freely. Still, again, no sign of moisture at all.

I appreciate everyone's help. I guess all I can do is keep monitoring it.
 
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