Replacing pressure tank


  #1  
Old 03-15-15, 06:36 AM
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Replacing pressure tank

This pressure tank has been here for around 30 years so I'm sure it's time for changing it.
Everything seems to work fine but there a fe wpoints that make me think it's done for:
- when I knock on the tank it sounds solid probably meaning the bladder is broken?
- the pressure switch has started making a creaking noise when it turns on
- there are no valves on the pipes, which I presume means that if anything leaks or bursts, the entire tank & 100ft well outide will empty itself into the house?

Firstly, if I replace it, how do I disconnect the pipes without getting the well water from emptying itself everywhere & also the tank?







 
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Old 03-15-15, 06:52 AM
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You did not say what type of well pump you have but since you are working on the pressure side of the pump changing the pressure tank will not affect it or the piping to the well. First turn off the circuit breaker to your pump. Then open a faucet until all the water stops flowing. I would replace all the galvanized fittings next to your tank especially since it looks like someone put the paint can lid there to catch a slow leak. It also would not hurt to change the pressure switch as well.
 
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Old 03-15-15, 06:53 AM
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hello...

You need to turn off the electric to pump and pressure switch..
Then drain the tank from the valve there..
Remove poly pipe, well side and house side.
Remove electric prom presure switch.
Then slide tank out and tip on its side to remove the whole assembly remaining...

IMO best to maybe repipe and replace with all new pipes , tees, pressure switch...etc.

Have you removed the red cap on the tank and checked the air charge? The tank may still be good.. If water comes out then you know the bladder inside is shot...

Let us know
 
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Old 03-15-15, 07:00 AM
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how do I check the air charge? and is there aything to do after that or will it re-pressurize if I release air...or water?
Also, is there any need to put valves into the piping? eg to shut water off when leaving the house?
 
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Old 03-15-15, 07:30 AM
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Unscrew that red cap on the tank. There is an air valve like a bike tire. Check air with a pressure gauge..

If the bladder is still good you can add air with a compressor...

Let us know..
 
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Old 03-15-15, 09:26 AM
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It's reading 32PSI, no water came out.
The pressure switch seems to read around 40-60 PSI depending on where in the cycle it is.
The bottom of the tank has a lot of rust around it.
Should the pipes from the well have valves on them?
 
  #7  
Old 03-15-15, 02:46 PM
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I think all pipes should have valves and "T"'s on them inside and outside the house so if something goes wrong it can be taken care of. But if the pipes are someplace where it doesn't much matter, say in a shed or a basement with a drain, then it's not that important.

Nobody I know shuts the water off when leaving the house unless they are going to be gone for over a month.
 
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Old 03-15-15, 02:52 PM
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When you read the air pressure, was there water in the tank or did you drain it and leave the tap open. If you drained it and a tap was open, then your tank is probably fine. You might want to add some air to bring it to 2psi below your cut in pressure (38psi in your case). This will provide more water from your tank between pump cycles and provide a little longer life for your pump.

As for a valve between the pump and the pressure tank. Does your well push water into your house even when the pump's electrical is turned off and the pressure tank is empty. If so, then this is called an artesian well and I would want a master shut off valve for that.

In your original post you talked about a burst pipe event causing your well and tank to drain into the house. As I said above, the well will only drain if your well is artesian. If you shut off the pump's electrical supply and you turn off the red valve to the right of the draining valve in your picture, that looks like it would shut off all the water from your tank and well and protect you from the problem you are discussing.
 
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Old 03-15-15, 03:55 PM
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It's a well that is 100ft in the ground (the pipe), but it does need a pump to get water across to the house.
So, are you saying that if the electrics for the pump are off, then no water can come through the pipes?

What I'm worried about is a leak between any place where the poly pipe joins a metal/brass pipe and that springs a leak, and then the well pump continues to pump water through.

I presume stopping the tank from emptying itself is separate and controlled by that red valve on the right. So, the only other thing would be a burst presuure tank from all the rusting at the bottom. Not sure how bad it is underneath but I can see it - could just be surface.

The pressure of 32psi was with the tank full of water.
 
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Old 03-15-15, 04:29 PM
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OK, so we still don't know about the tank. When the tank is full of water you will end up reading the pressure from the water. No leak out the Schrader valve is a good sign but that does not mean the tank's bladder is not compromised. If you empty the tank of water, leaving a tap open, measure the air pressure. It should be around 38psi. If it is leaking you will probably get something close to zero pressure.

If a pipe in your house broke right now and you did nothing your pump would continually pump water into your house until your well ran dry. Let's assume your house would be a disaster long before that. If you turn off the electrical to the pump and you burst a pipe, the water in the pressure tank will still flow out into your house until the tank is emptied. That is still a lot of water and can do a lot of damage as well. That red tap to the right looks like it would not only shut off the water from the pressure tank but also from your well. So if you turned it off I would think your house would be protected from a burst pipe.

All this is assuming that the red tap I am talking about is on the house side of the pressure tank and not the well side of the pressure tank. That is how it looks to be in the picture but you would know for sure. So if the red tap is on the house side of the pressure tank then it will shut off both the pressure tank and the well. Easy test. Turn off the red tap and open a house tap. Opening a tap is the same as bursting a pipe. Is the water pressure gone or still there?
 
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Old 03-16-15, 09:55 AM
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Determining if the pressure tank is good can be a multistep process.

Short method:

1. Wait for the well pump to shut off.
2. Leaving the pump powered up, draw bucketfuls of cold water and carefully measure the quantity until the pump restarts.
3. If you drew several gallons, like seven or more, then the pressure tank does not need urgent replacing. (Drawing fewer gallons does not prove that the tank is bad; follow other procedures such as in a sticky thread of this forum.)

Long method:

(We suggest that you turn off the water heater heat because it is possible that siphoning of the hot water tank could occur duing these tests and the water heater will self destruct if it kicks on while not full of water.)

1 Turn off the pump and open a cold faucet. Wait for the water to stop flowing.

2. Measure the air pressure in the pressure tank.

3. Either set the well pump turn on pressure to 2 PSI more than the pressure tank pressure or, using a bike tire pump or similar pump, set the pressure tank pressure to 2 PSI less than the pump turn on pressure.

4. Set the pump turn off pressure to 50% more than the turn on pressure, for example 35 PSI turn on, 51 PSI turn off.

5. Close the faucet(s) and turn on the pump.

6. When the pump stops, draw bucketfuls of water out of a bathtub or other cold faucet, carefully measuring the quantity of water, until the pump restarts.

7. The pressure tank is okay if you draw about a third of its capacity before the pump restarts.

8. Turn off the pump and open the cold faucet again waiting for the water to stop. Now reset the pump turn on pressure, turn off pressure, and pressure tank pressure to what they should be (or what you want) for your system.

9. Have a hot faucet gushing water steadily before turning the water heater heat back on.
 

Last edited by AllanJ; 03-16-15 at 10:31 AM.
  #12  
Old 03-29-15, 02:46 PM
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I turned off the well pump (I do not know wht pressure it is set to as it is at the bottom of the artesian well). All I have access to is the breaker to turn it off.
I emptied the pressure tank and then tested the air pressure, it reads 0 PSI.
It's still working fine so not sure what the problem is and no water comes out of the valve, it reads 32PSI when filled with water.
 
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Old 03-29-15, 05:13 PM
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THe first step in the process is to find at what pressure the pump turns on. So, with the well pump breaker turned on you sit by the pressure switch and have someone open a spigot while you watch the water system pressure gauge. Note the pressure when you hear the pressure switch click on. Then once you have that pressure you can go on to bleeding down the system and setting the air pressure in the pressure tank.
 
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Old 03-29-15, 06:09 PM
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When you emptied the pressure tank you should try to set the pressure tank pressure to 2 PSI less than pump turn on pressure before turning off the tap and before turning the pump back on even if the tank went down to 0 PSI.
 
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Old 03-29-15, 07:10 PM
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If the reservoir was empty, shouldn't it be reading a positive air pressure if working properly?
 
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Old 03-30-15, 05:07 AM
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It sure sounds like that pressure tank is toast. When the bladder ruptures all the air will escape out the pipes when you drain the system.

With the tank still empty and a tap open, try to put air in it and see if it holds air. If it doesn't, replace the pressure tank.

You will still need to be sure what pressure your pump kicks on at so you can set the air pressure correctly on this tank or the new one.
 
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Old 03-30-15, 04:30 PM
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The new pump comes already pressurised so would I have to adjust the pressure switch instead?
 
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Old 03-30-15, 07:21 PM
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No. You should not need to adjust the pump. You just want to be sure what the water pressure is when the pump starts up. If you are pretty sure it is 40psi, then you will want to set the air in your pressure tank to 38psi.

First, however, you want to confirm if your pressure tank can even hold air pressure. In other words, is the diaphragm breached or not. With no water in the tank and a water tap open, if the diaphragm is breached, you should not be able to build any air pressure up in the tank. If would all flow back out the open tap. If the diaphragm is not breached the tank will hold air, even with a tap open.

Now once you have a good tank with a good diaphragm, add air until it is 2 psi below the cut in pressure of your pump.

If you are not sure of the cut in pressure of the pump, you can fill up your current pressure tank again, with water. Even if the diaphragm is breached, the tank will still work for a short amount of time (a couple of weeks or so). As long as it allows the pump to come on and off again you can see what pressure your guage reads when it comes on. Now eventually, if the diaphragm is breached and you keep using it, the air that gets trapped in the tank, that is allowing it to work for the short period of time, will start to dissolve into the water. That is what the diaphragm is for, to prevent the air from dissolving into the water, by keeping the two separated. As this air dissolves into the water, the amount of water your tank puts out between pump cycles will be less and less. Eventually you will be at a point where almost every time you turn a tap on the pump will kick on and off and on again, etc. Basically the pump will be short cycling. This is really hard on a pump and why you want to have a good working pressure tank with a good diaphragm.
 
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Old 04-06-15, 08:23 AM
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The pressure switch seems to come on at 26PSI. Is that too low?
If the diaphragm was okay, and the tank empty, should I be getting a reading?
If it's broken, then how is it maintaining pressure when full of water?
 
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Old 04-06-15, 06:58 PM
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OK, perhaps we have some confusion here. To get a reading on when your pump switches on, the entire system needs to be FULL of water and you are measuring WATER pressure, with a guage connected in your water system.

To measure the AIR PRESSURE IN THE PRESSURE TANK, you need to EMPTY the tank completely of water and leave a tap open. Now measure the air pressure with something that can read the Schrader valve on top of the pressure tank. It should read 2 psi below the pressure your pump switches on.

Now to answer what I think your other questions are.

If the diaphragm is OK, you should be able to measure the air pressure from the Schrader valve, even when the system is empty of water, since the diaphragm will maintain the seal to contain the air. If the diaphragm is breached and you have the system empty WITH a tap open, you should not get any positive pressure when measuring the air from the Schrader valve.

If the diaphragm is breached and you fill the system with water, some air will get trapped in the pressure tank and when the water rushes in and compresses that air to the cut out pressure level of your pump, the pump will shut off. This trapped air will make the system seem like it is working as it did when the diaphragm was good, but you will be getting a lot less water between pump cycles then you should, and this water amount will keep decreasing over time as the air dissolves into the water. Eventually (few weeks) there will be so little air trapped in the tank that the pump will not only come on every time a tap is opened, but will effectively start short cycling as a tap is left open. Unless you want to keep emptying the tank, every 2 or 3 weeks, so you can re-trap some more air in the pressure tank, you should replace a pressure tank when the diaphragm is breached.

Just so you know how your water system works. If the air in the tank is at 2 psi below the cut in pressure of the pump, when the water system starts to fill from empty, the tank will stay empty until the water pressure is at least equal to the air pressure. Once the water pressure increases above the air pressure, the water can enter the tank and it starts COMPRESSING that air above what it was set at. Eventually enough water enters the tank AND the air compresses to a level that exerts a pressure equal to your shut off pressure of your pump and your pump shut off. Once you open a tap, that compressed air pushes the water out of the tank to your faucet or toilet or whatever. As the water leaves the tank, the air pressure decreases and when it reaches the switch on pressure of the pump, the pump starts up and refills/re-compresses the air again.

So you see that it is the AIR that creates all the water pressure when the pump is off. Without it, you will have no pressure. The reason you want the air pressure a little below the cut in pressure of the pump is to ensure that the tank never empties completely. If it did, you would get a quick drop off of pressure just before the pump kicked on since the air in the diaphragm cannot push on the water outside of the tank.

I hope that helps. Good luck.
 
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Old 04-07-15, 07:19 AM
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Another problem with a ruptured bladder (diaphragm) in a pressure tank, which may or may not show up in your system, is trapped water. The ruptured bladder could rest on the tank outlet preventing the tank from emptying. At that moment the system pressure will make a sudden drop even though the tank pressure is well above pump turn on pressure. If the pressure switch is in the water line then the pump will turn on sooner than it should. If the pressure switch is in the tank then the pump could fail to start with near zero faucet pressure. When this happens is unpredictable.

Also, with less space for air in the tank the air pressure and therefore the system pressure goes up and down more quickly with less water entering and leaving the tank and the pump makes shorter cycles.
 
  #22  
Old 04-08-15, 06:53 AM
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It's also possible for your 30 year old tank to have NO bladder. The tank I just replaced looks like a smaller model of your tank, red cap on the side & all, and was just a small air-over-water surge tank. I drilled a 2" hole in the top to verify the schrader air valve was in fact connected to nothing.

I would replace that type of tank regardless of its appearance or condition.

 
  #23  
Old 04-08-15, 07:11 AM
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I drilled a 2" hole in the top to verify the schrader air valve was in fact connected to nothing.

Yes that is correct that its connected to nothing. Thats the air side. The bladder is on the water side. That tank has a bladder.

This is how most steel tanks are.


The fiberglass tanks are opposite. The water fills in the tank and the bladder is on the air side.



Tanks with no bladder need an air volume control to add air every time the pump comes on..That is a whole different set up..
 
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Old 04-09-15, 07:03 AM
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I mis-spoke. There was nothing in the tank except water and 30 years worth of nasty crud build-up.
 
  #25  
Old 05-08-16, 05:52 PM
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Right. Drained water, left tap open, it measures 0psi. Tried pumping it up with a bicycle pump, stays at 0.
However, the system does keep pressure when filled with water. From the above posts, this is supposed to decrease over weeks as the little air in tank dissolves into the water and then it will short cycle.
However, it never seems to totally short cycle.
Switch comes on every 30 seconds or so as pressure drops below 26.
How is it maintaining pressure if the bladder is ruptured?
 
  #26  
Old 05-09-16, 05:45 AM
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When the system was empty, air got trapped in the tank. Once you filled the tank with water that trapped air gets compressed. As long as you have compressed air in the tank, your house will receive water pressure because that compressed air will push the water out of the tank. The problem with a ruptured bladder, is that over time, that air will dissolve into the water and decrease. Keeping the air and water separate is the sole purpose of the bladder inside your tank. As the air dissolves and therefore decreases in amount, so does the amount of water you get between pump cycles. I can't say for sure how long it will take but at some point you will find that the pump kicks on every time you draw the smallest amount of water. Perhaps a cup or so. What that would mean is if you were taking a shower, the pump would come on and a few seconds later go off and a few seconds later come back on, etc. Not quite the short cycling of on, off, on, off, on, off, but close enough to cause your pump to be severely overworked. It is the coming on and off that is the hardest on your pump, not the actual pumping of the water.

If you can't bring your tank to a positive air pressure with it empty and no water in the system, it is toast. You are lucky in that this type of failure does not leave your house without water so you can decide when you change it out, but if it were me, I would change it. For the benefit of your pump, put in the largest pressure tank your area can accommodate. I believe you have a submersible pump (but I am not sure). Your highest expense, some day, would be having to change the pump. Pulling it from your well, as well as the cost of a good submersible is not cheap. I would do everything I could to delay that day as far into the future as possible.
 
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Old 05-09-16, 06:54 AM
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That's the only thing I don't understand is that it won't hold air pressure empty yet I have also never ever put any air in whilst there was water. If that air dissolved slowly over time then it should short cycle. Yet it cycles on 30 second increments for a 19gl tank. It's not short cycling with each turn of a tap.
So is there still air trapped in there after 5 years plus?
 
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Old 05-09-16, 09:59 AM
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Can't really say. Maybe it is a very small bladder leak. You can just leave it for now and keep an eye on it and see if the water drawdown is decreasing. The 30 second number you have is useful but it will vari depending on how much water is actually being drawn the tap and any changes in the water level in your well, etc.

To get a really good measure you should let the pressure tank fill up until the pump shuts off. So when the pump kicks on, turn off the tap and let the tank fill up. Now open a tap into a measurable container. How much water do you get before the pump turns back on?

Your system, assuming a cut in/cut out pressure switch setting of 40/60 and a 19 gallon tank, should give a theoretical maximum of around 4.9 gallons of water between pump cycles. If you get 4 gallons of drawdown water you are probably doing pretty good. With zero psi starting air pressure, I am assuming you will get a lot less then that. I can't say how much but it should be less. The main question is, "does the amount of drawdown water decrease overtime?".

Measure it today, measure it next week, measure it the week after that. If no measurable change, measure it in a couple months, and if no change then, forget everything I said.

A 30 second cycle is not going to work your pump too hard. A preferred cycle is closer to a minute but your tank size will put a limit on that. 30 seconds is fine if it is putting 4 gallons of water into the tank. If it is not then that is where my concern would be.
 
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Old 05-09-16, 04:15 PM
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In 30 seconds, I think I would be lucky to get 1 gallon from the kitchen sink. Although aren't most kitchen taps now restricted to 2-3 GPM?
It's more like a 30/50 switch now that I looked at it.
 
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Old 05-09-16, 04:41 PM
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The restrictions of a tap do not matter in what I am talking about. There will be a certain amount of water that is drawn from the pressure tank that will bring the pressure down to the cut in level of the pump. The pump will then pump that exact amount of water back into your tank. It will keep pumping water in until the pressure from the compressed air increases to the cut out level of the pump. That is how your system works. If water in a tap is restricted it will take longer for the tank to drawdown to the cut in level and if you were to open two taps or three tap it will take less time to drawdown that same amount of water. In either case, the amount of water you get between the pump on and off cycle, will be the same.

At a 30/50 switch level and a 19 gallon tank you should get a theoretical maximum of 5.7 gallons of water between pump off and pump back on again (1 drawdown cycle). No one gets the maximum but if you could get more air in your tank you would get closer to the maximum. I would be happy with 4.5 gallons with your set up, which is probably what you could get if you could pump up the tank with air to a pressure of around 28psi (2 psi below your cut in pressure). That is how your tank is supposed to be set up.

As you have seen. It will work with a breached bladder, but the pump will come on and off about 4 times as often (assuming you are getting about 1 gallon now). Also the amount of drawdown you will get with a breached bladder will decrease overtime. The air that is in your tank now, will dissolve into the water. I can't say exactly how long it will take, since I don't know how big of leak it has, but it will happen.

You can always just empty the tank and refill it and get back to where you are now but it is something you will need to keep doing. You can also add air to a tank that has water in it. The reason you could not add air to the tank that was empty when a tap was open was because the air just escape out the tap. I asked you to do that to confirm that the bladder was breached. If your bladder was OK it would have trapped air in the tank and allowed you to get to a positive air pressure. If you have water in the tank the water will trap added air in the tank. So you can just periodically add some air but when water is in the tank it causes problems with measuring the air pressure. So you might end up adding too much air. If the air pressure is higher then the cut in pressure of the pump it will cause other problems.

With all that being said, I would replace the pressure tank. Everything else is just a band aid, in my opinion.
 
 

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