My sure flow pressure tank oscillates every 10 seconds, faster if I turn on a tap in the house. I have drained the tank and isolated it from input and output. I rented a compressor but the tank will not fill. The air goes in but the input and output pressure gauges remain at zero.Does this imply that the bladder is kaput?

Miserable and without water,

Chris

Hi Chris and Welcome to The Plumbing Page at AMHD.com. You're responding to a 5 year old dead threads so I gave you one of your own. Please check the date before you post. Thanks

My sure flow pressure tank oscillates every 10 seconds
Do you mean that your pump cycles on and off? If not, please explain.
Put a bladder tank. Back in the system and run the pump. When the pump shuts off opened restrictor valve on top of the tank. If water comes out then you have a ruptured bladder and the tank must be replaced. The air setting in a tank should be set at two PS I under the cut ln point on a control box. Let me know what you find. Good luck, Tom

Hi Chris and Welcome to The Plumbing Page at AMHD.com. You're responding to a 5 year old dead threads so I gave you one of your own. Please check the date before you post. Thanks

do you mean that your pump cycles on and off? If not, please explain.
Put a bladder tank. Back in the system and run the pump. When the pump shuts off opened restrictor valve on top of the tank. If water comes out then you have a ruptured bladder and the tank must be replaced. The air setting in a tank should be set at two PS I under the cut ln point on a control box. Let me know what you find. Good luck, Tom

Thanks Tom,

Not exactly. The pump runs and the pressure in the tank oscillates rapidly between it's,low cut in speed and it's higher cut out speed (switch).If It does this continuously. The cycling is about 10 seconds and it never stops. I have drained the tank and tried to inflate it but although the air goes in the pressure gages show no pressure. ````I checked every inch of the plumbing and there are no leaks!```````111

[QUOTE=Welschrisby;3551246]
Thanks Tom,
Not exactly. The pump runs and the pressure in the tank oscillates rapidly between it's,low cut in speed and it's higher cut out speed (switch).If It does this continuously. The cycling is about 10 seconds and it never stops.

I have drained the tank and tried to inflate it but although the air goes in the pressure gages show no pressure.I checked every inch of the plumbing and there are no leaks!

The water pressure gauges will not show a change when doing the air pre-charge (which is what your are doing). That is because what you are doing is inflating the bladder inside the tank.
Turn off the pump at breaker. Drain all water from the tank. You probably have very little or none at this time in the tank.
Check air pressure at valve stem with tire pressure gauge. The pre-charge air pressure should be 2 pounds less than the cut on pressure of the pump pressure switch.

Pump should cycle normally. If problem returns in a few days or a few weeks (depends on tank size) you have a ruptured bladder and tank will need to be replaced.
If

One more time! Run the pump up the pressure and push the stem down on the snifter valve. Does water come out? Let me know, back to you, Tom

The pump runs and the pressure in the tank oscillates rapidly between it's,low cut in speed and it's higher cut out speed (switch).If It does this continuously. The cycling is about 10 seconds and it never stops.

"It never stops". If that means it does this whether you are using water, then a leaking check valve OR a major leak in the well pipe become a suspect.

Is the pump in the well or above ground?

Your tank might be bad, but when you drain the tank and put some air in it, then the tank should behave reasonably well, at least for the next few weeks. Personally, I don't think the bladder is shot. If it was, then your gauges would respond when you tried adding air.

Thank you HK, maker of widgets. You my friend are a gentleman and a scholar! The pressure tank was OVER inflated because I had not realized, as you so wisely pointed out, that it's pressure could only be read from the tire pressure valve and not from either of the pressure gauges. I am fortunate that I didn't blow myself up! Beware the not so gifted amateur, I am indeed chastened by my ignorance - and I have water!



The water pressure gauges will not show a change when doing the air pre-charge (which is what your are doing). That is because what you are doing is inflating the bladder inside the tank.
Turn off the pump at breaker. Drain all water from the tank. You probably have very little or none at this time in the tank.
Check air pressure at valve stem with tire pressure gauge. The pre-charge air pressure should be 2 pounds less than the cut on pressure of the pump pressure switch.

Pump should cycle normally. If problem returns in a few days or a few weeks (depends on tank size) you have a ruptured bladder and tank will need to be replaced.
If

First of all - Tom, the answer to your question: No water comes out of the sniffer valve when the pump is up to pressure.

However - the pressure at the pressure gauge gradually falls and, to compensate, the pump now fires up about every 10 minutes and runs for about 1 minute. Sounds like a plumbing leak - Yes? But I have checked all pipe runs and all connectors and there is no leak.

But, when I check the pressure at the sniffer valve with my tire pressure gauge I find that the pressure is increasing alarmingly every time the pump fires up. In fact, it gains about 10lbs every time the pump fires. Where is the tank getting this pressure from? Will it explode if I leave it to continue in this way? Why is this happening?

Thanks



Thank you HK, maker of widgets. You my friend are a gentleman and a scholar! The pressure tank was OVER inflated because I had not realized, as you so wisely pointed out, that it's pressure could only be read from the tire pressure valve and not from either of the pressure gauges. I am fortunate that I didn't blow myself up! Beware the not so gifted amateur, I am indeed chastened by my ignorance - and I have water!

And now Tom, you were right, water is spraying out of the sniffer valve.



First of all - Tom, the answer to your question: No water comes out of the sniffer valve when the pump is up to pressure.

However - the pressure at the pressure gauge gradually falls and, to compensate, the pump now fires up about every 10 minutes and runs for about 1 minute. Sounds like a plumbing leak - Yes? But I have checked all pipe runs and all connectors and there is no leak.

But, when I check the pressure at the sniffer valve with my tire pressure gauge I find that the pressure is increasing alarmingly every time the pump fires up. In fact, it gains about 10lbs every time the pump fires. Where is the tank getting this pressure from? Will it explode if I leave it to continue in this way? Why is this happening?

Thanks

It's a bit inconsistent to say you have water coming out the air valve and to say you have increasing air pressure. If you got water out the air valve you definitely have a ruptured bladder. While you set the pre-charge pressure to 2 lbs below the cut in pressure with the tank empty, it will go up to the cut off pressure as the tank fills with water. Perhaps you could explain.

Thank you for your careful and detailed reply. Does it make a difference that there is no well and that the water is being pumped from an above ground 1000gal cistern? There is a check valve in the input line and I can hear it working if I put my ear to it, but there is so much noise in my small pump house that I am not sure which hissing is coming from where. There are two inline filters which I can bypass and I am pretty much 100% sure there are no leaks in the input line. Could air be escaping via the check valve into the cistern?

The main thing I want to avoid is spending $400 on a new tank unless I am convinced that I have exhausted all other options. In your estimation do you think I should change the check valve just in case, or is it pretty certain to be the bladder? Or any thing else I could try? I realize of course that you can only make an informed guess so please don't hold back, I am most grateful for all the help I have received and hope that I can help someone out in turn.



I would say (make that guess) that you

1. have a ruptured bladder
2. have a check valve on the pump line. Logic would say that it would be between the pressure switch and the tank.
3. If you have a foot valve at the bottom of the well it is leaking. Or you do not have a foot valve.
4. You have a leaking or ruptured well pipe (between the well head and the pump at the bottom of the well).

Logic is,
Pump comes on and gets up to pressure. Pump shuts off. Water in the well pipe leaks out, due to having a leaking foot valve or not having a foot valve and due to a leak in the well pipe. After pressure on well pipe is relieved, water continues to leak at the bottom of the well. That sucks air into the well pipe at the point of the leak in the well pipe. The check valve keeps water in the tank from coming back into the well pipe. When pump come on again, the water it is pumping, pushes the air trapped in the pipe past the point of the leak and into the tank. Because of the ruptured bladder that shows up as increasing air pressure.

Go to the well head and listen for the sound of a pipe leak when pump is running. You may be able to hear water running back down the well when pump is not running.

I know its a bit of a stretch to have so many thing wrong at one time but its about the only way you could get more air into the tank.
Kind of explains why you were not getting any water before even though the pump was running. Not only was the tank filled with air, the pipe from the well head was also filled with air.

The hissing sound is definitely coming from the pressure tank and continues for some time after the pump has switched off. The tank does not ring hollow when I tap it with a metal object. There is no pressure on the low pressure side of the pump and the high pressure side keeps between 20 and 40psi. When I turn the power off and drain the tank a large amount of aerated water drains out. Before I turn the pump on again it rings hollow. My tire pressure gauge reading goes up 10psi every time the pump fires. Water is getting through to the house but the pressure is pretty low. The pump fires up every 15 minutes or so even though no water is being drawn

Wel, it is possible that the hissing sound you are hearing is coming from the air valve on top of the tank. If you want to find out, put your finger over the valve and see if the hissing stops. Or you can mix up a little soapy water and put some on the valve. If it bubbles, then the valve is bad. The good news is this: You can simply replace the valve stem and fix the problem.

However, there is still a question to be answered. Is this cycling going on all the time, or only when water is being used? If it is all the time, then the CV becomes the suspect. If it is only when water is being used, then the tank is the place to look. It's a very simple yet important question to be answered.

I just fitted a new pressure tank and, to my chagrin I still have the same problem! Vis: every time the pump fires up it increases the pressure at the sniffer valve of the pressure tank. The water pressure at the house faucets is poor. Do I need a check valve downstream of the pressure tank?

Wel, it is possible that the hissing sound you are hearing is coming from the air valve on top of the tank. If you want to find out, put your finger over the valve and see if the hissing stops. Or you can mix up a little soapy water and put some on the valve. If it bubbles, then the valve is bad. The good news is this: You can simply replace the valve stem and fix the problem.

However, there is still a question to be answered. Is this cycling going on all the time, or only when water is being used? If it is all the time, then the CV becomes the suspect. If it is only when water is being used, then the tank is the place to look. It's a very simple yet important question to be answered.

Thanks for this, In answer to your questions: neither the new or the old tank leaked at the sniffer valve. Also the pump comes on without someone drawing water at a faucet.
As you will see from my other posting I replaced the pressure tank yesterday but still have the identical problem. The pump fires in response to falling pressure WITHOUT any water being drawn from a Faucet. IE this is in response to falling pressure on the output side of the pump. But why is it that the pressure in the pressure tank rises when the pump fires up? Perhaps the falling pressure is due to water volume increasing in the pressure tank?

Here is my theory: Water must be feeding back into the pressure tank. Because of this increased volume of water, the bladder is compressed thereby increasing the air pressure at the sniffer valve every time the pump fires up.

Could it be that I need to put a check valve in to prevent water from feeding back into the tank?

What do you think?

This is what I think:


However, there is still a question to be answered. Is this cycling going on all the time, or only when water is being used? If it is all the time, then the CV becomes the suspect. If it is only when water is being used, then the tank is the place to look. It's a very simple yet important question to be answered.


"It never stops". If that means it does this whether you are using water, then a leaking check valve OR a major leak in the well pipe become a suspect.

Your tank might be bad, but when you drain the tank and put some air in it, then the tank should behave reasonably well, at least for the next few weeks. Personally, I don't think the bladder is shot. If it was, then your gauges would respond when you tried adding air.

It sounds like the checkvalve is not doing its job. It is supposed to prevent water from running out of the pressure tank and back into your holding tank. It is a one way gate leading from the holding tank to the pump.

Here is my theory: Water must be feeding back into the pressure tank. Because of this increased volume of water, the bladder is compressed thereby increasing the air pressure at the sniffer valve every time the pump fires up.

Could it be that I need to put a check valve in to prevent water from feeding back into the tank?

Water feeding back into your tank?? From where??

When your pump cuts off, if the CV is not working, then the water simply runs back into the holding tank from the pressure tank. Replacing the CV is the relatively cheap and simple fix. I really wish you had tried that before replacing the tank. I fear you simply wasted that money.

Thank you for your concern, however it turns out that I had two problems:

1. The pressure tank was shot
2. the CV was not working.

It took me a while to get there but thanks to all you good people on ASK Me I got there in the end.

Thanks everyone for your great advice




When your pump cuts off, if the CV is not working, then the water simply runs back into the holding tank from the pressure tank. Replacing the CV is the relatively cheap and simple fix. I really wish you had tried that before replacing the tank. I fear you simply wasted that money.[/QUOTE]