Testing Pressure Tank

Discussion in 'Pumps and Tanks Well Forum & Blog' started by gojoe3, Apr 18, 2013.

  1. gojoe3

    gojoe3 New Member

    Messages:
    68
    Hello valveman and others,

    My Well-x-trol 44 gallon pressure tank has been malfunctioning. It short cycles when our softener or pH neutralizer backwashes.
    My wife is ready to kill me it wakes her in the early am every time the softener regens or the pH tank backwashes.
    I just wear earplugs and tell her I'll fix it when I have a chance to determine what is wrong. It's been a few weeks now and I'm concerned about damaging our well pump. I would like to test it to determine if the bladder has failed or if the pressure switch is bad.

    I understand that in order to check the pressure in the tank, I must first shutoff the power to the pump and then drain the tank.
    Then I'll use a tire gauge to check the pressure at the schrader valve on top of the tank. I understand that the pressure should be at least 2 psi less than my cut-in pressure. I check it annually and the pre-charge seemed ok, now I am wondering if I have been doing it improperly.

    I recently read the "Pressure Tank Maintenance" thread posted by valveman, a portion of which I have copied and pasted below:

    "To check the air pressure in a bladder tank the power to the pump must be turned off. Then a faucet should be opened until water stops coming out of the tap. While the pump is off and the faucet is still open, you can check the air pressure at the schrader valve on top of the tank. You will need to use a car tire pressure gauge on the schrader valve. The air pressure in the tank should be 2 to 10 PSI below the "start" pressure of the pump. IE; with a 40/60 pressure switch, the air pre-charge in the tank should be no higher than 38 PSI and no lower than 30 PSI. Use an air compressor to pre-charge the tank to the correct pressure. If the air is coming back out of the open faucet, then the bladder is busted. If while holding the valve core down on the schrader valve, water comes out, the bladder is busted. If the schrader valve will not accept air from the compressor, the bladder is most likely busted."

    I do not understand why one would need to open a faucet to drain the tank rather than just closing the valve after the pressure tank, so that you are not draining down the entire house and any associated conditioning equipment. Why not just drain the tank using the drain valve located on the tee coming off the tank? If the pre-charge is low and air is added, would air escape out of the open drain valve if the bladder was bad?

    If I check the pre-charge psi and it is correct, then I would like to replace the, 20 year old, Square-D 40/60 pressure switch with a new one, to see if that is the problem.

    I read the "Replacing a Pressure Switch" thread started by rmhall17 and read the reply by sammyhydro11 .

    I copied and pasted a portion here :

    "You first want to make sure its not coming from a conduit that comes out of the foundation and into the switch. If it is, you need to remove that conduit and patch the foundation. If it is the switch itself, you need to replace it. Shut the power off at the circuit breaker and get yourself some electrical meters and check for voltage to be sure that it is off. You then need to turn on some faucets and drain the tank. When its drained, the gauge on the tank should read zero. Next step is to shut the main valve going to the house get a bucket,put it underneath the spigot on the tank , and open it to drain the water left in the pipe. Next you need to un wire the switch, get both the wires from the panel and the wires going to the pump out of the switch. With a wrench remove the switch and replace it. If the nipple stays in place then put some plumbers tape and pipe dope on the threads and simply screw the new switch on. If the nipple comes off with the switch, then you will have to remove the nipple from the old switch,do the tape and pipe dope on both ends of the nipple,and install the switch. Wire the switch by screwing the leads from the breaker on the outside lead terminal screws and the pump leads on the inside terminal screws. If you have a 30/50 or 40/60 switch you need to adjust the air in the tank so the pressure is 2lbs below the cut in pressure. Once that is all done, shut your drain spigot off at the tank and turn the power back on. the pressure should build to its shut off pressure. Turn the water on slowly to the house and the pressure will start to drop. If all your settings are right, it should cut in at the switches set cut in pressure. Once it cuts in shut the water off to gthe house and make sure it builds to the correct pressure. If it does just turn the valve back on, shut your faucets off and you are good."

    I will be draining and testing my tank today and if the bladder seems good then I will be replacing the switch. So these directions are great, but I was wondering if I really need to drain down the entire house using faucets to drain the tank, or can I just drain the tank using the drain valve on the tee?

    BTW, I had a well guy here on Monday to assess the situation. He said I needed a new pressure tank. He did not test anything. I just told him it was short cycling when the water conditioning equipment was backwashing.

    I am not familiar with all Forum etiquette so I hope it is ok to use Bold to highlight.

    I appreciate any suggestions. Thank you.
  2. valveman

    valveman Moderator Staff Member

    Messages:
    4,425
    Location:
    Lubbock, Texas
    You can close the isolation valve going to the house if you want. The drain on the tank is as good a ”faucet” as any of them to drain the tank. With the pressure tank drained, the house is effectively at zero pressure as well, so it really doesn’t make much difference.

    Yes leave the drain faucet open while adding air to the tank. If air comes out the drain faucet, the bladder is bad. Higher than normal air pressure in the tank usually means the bladder is busted as well.

    A 44 gallon tank holds about 12 gallons of water as well. So you can measure this in a bucket as the pressure drops from 60 to 40. With the correct air charge, if you are not getting close to 12 gallons out of the tank, something is wrong with it.

    It doesn’t matter how old the pressure switch is. If the pump still comes on at 40 and off at 60, the pressure switch is OK.

    If everything checks OK, and the only time you get a short cycle is when back-flushing, there could possibly be some restriction in your flush line.

    Your use of Bold actually helps in this case.
  3. gojoe3

    gojoe3 New Member

    Messages:
    68
    Valveman, thanks for the quick response.

    Thank you for confirming the use of the isolation valve and drain valve to properly drain and test the tank.

    Thanks also for adding additional telltale signs of tank failure.

    I'm glad it was ok to use Bold to highlight the question I needed an answer to.

    I actually spoke with Cary at CSV yesterday in reference to using a CSV on my system which also has a Clack air injector for the iron.
    I started a thread about this at the water softener forum here. It is titled "sizing new pressure tank and CSV..."
    I just went there and see that you replied to that thread.
    It will be nice to get this all figured out.
    I wasn't sure where to best post this issue. I have a few relating to my system.

    Thanks for the assistance.
  4. gojoe3

    gojoe3 New Member

    Messages:
    68

    Thanks for the advice.
    I hope it's ok to copy and paste (below) from the other thread I have going here at the Water Softener Forum, it is titled "sizing new pressure tank and CSV..."

    I just finished draining the pressure tank down to test it and check the pre-charge, as per valveman's directions.
    BTW, I have another thread going here at the Pumps and Tanks Well forum titled "Testing Pressure Tank".
    I am still unsure as to whether my pressure tank is bad or not. I will copy and paste what I've written below, to the other thread I have going here.

    I ran water until the pump turned on at the 40 psi cut-in, filled the tank hit 60 psi and shut off, then I shut the power off, isolated the tank, and drained it down.
    I only got 5 gallons of water out. With the tank empty I used a tire gauge to test the pressure at the schrader valve on top. It read 38 PSI.
    Then I closed the valve turned the power back on (tank still isolated) and the pressure switch just made a click-click, click-click sound so I shut the power off.
    I opened the drain to see if any more water would come out but only about a quart more came out. I turned the power back on and it made the same click-click sound a few times so I shut it off again. Then I opened the isolation valve (no water running anywhere), turned on the power, and the pump came on, pumped up to 60 shut off dropped to 40 came on 5 seconds, pumped up to 60, 5 seconds, dropped to 40. It did this short cycling 5 times and then stopped, psi remained at 50 +/-.

    I still wanted to check the GPM, so I opened the drain valve and filled a 5 gallon bucket. It took 32 seconds. The water which was clear earlier was now pretty rusty.
    When I shut off the drain valve the pump short cycled again same as before, 5 times at 5 second intervals, then stopped. Two minutes later it short cycled one more time.
    I repeated this to confirm the GPM test and it filed the second bucket in 30 seconds. The water was less rusty but the pump still short cycled 5 times then two minutes later one last time. There was no water running anywhere else in the house.

    Fifteen minutes later, my wife used the kitchen sink and the pump came on, it seemed normal. It took its time to climb to 60 psi then stopped and settled in at 47 psi and stayed there.

    So, I am assuming that the pressure tank's bladder is bad, because only 5 gallons drained out and I should have gotten aprox. 12 gallons out of a 44 gallon Well-x-trol.
    So, I guess the bladder is waterlogged? I don't understand why the pre-charge remains good at 38 PSI. I added air a year ago to bring it up to this 38 PSI and it has remained there.

    I'm going to go down to the basement after dinner and try your suggestion about seeing where the GPM stands at that certain pressure window.

    It would be great to get some input as to whether others here think my tank is bad or not. I am concerned about killing my well pump with all the short cycling, etc.. I am shopping for a new well tank and think I will go with a Wel-x-trol WX-251 (62 Gal) or 255 (81 Gal) instead of the 250 (44 Gal) I now have.
    I have to decide on a 40/60 or a 50/70 Square-d pressure switch. Any advice would be appreciated.

    Then, later, I will try to determine if I can use a CSV with my new tank. I will plumb it in a way that I can add the CSV simply, unions etc., if it works out to be appropriate.
  5. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,919
    Location:
    NW Ontario, Canada
    My guess is that because you are aerating the water for iron removal, the the iron is precipitating and collecting in the space between the bladder and the tank wall, effectively reducing the drawdown capacity. As I mentioned in your other thread, you need to use the right kind of tank in that application.
  6. craigpump

    craigpump Member

    Messages:
    891
    Location:
    ct
    Youre not losing your air charge, so there is no way the iron can get between the bladder and steel shell of the tank. The only way iron could get on the backside of the bladder or diaphragm in a WellXTrol is if the diaphragm has ruptured.

    Sounds to me like you have accumulated a lot of precipitated iron in your tank and that's why you have lost your drawdown. Unfortunately, there is no way to clean that stuff out of the tank so your tank will have to be replaced. Recently we were called out on a pressure problem where the water was surging badly at the faucets. It turned out the tank T was plugged solid with iron. There was a micronizer being used before the tank and the iron simply plugged up the tank T.

    Either the 251 or 255 would be a good choice, but you still have this iron to deal with so you should go with something to get rid of the iron before loading another tank up with that crap. I would not put in a WP series Amtrol tank, they seem to have some reliability issues, way more than the WX series.

    I don't know anyone who installs 30/50 pressure switches, we all use 40/60.
    Last edited: Apr 18, 2013
  7. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,919
    Location:
    NW Ontario, Canada
    Perhaps you should look at a cutaway of how a bladder tank is made. It seems to be a common misconception that the water is contained inside the bladder which is not the case. The iron certainly can get in between the bladder and the side of the tank.

    Have a look at the following exploded view.
    http://www.aquascience.net/amtrol-pressure-tanks/index.cfm?id=503
  8. craigpump

    craigpump Member

    Messages:
    891
    Location:
    ct
    Perhaps it is you who should go back and look at the cutaway and reread what I posted.

    In a Well XTrol, the water is contained in the liner and under the diaphragm, this keeps the water from contacting the steel shell preventing corrosion from the inside out. The liner also prevents the water from getting a metallic taste. There are occasions when the seal at the entry port and the liner fail, but I rarely see that. Most failures in a Well XTrol are due to ruptured diaphragms, when the diaphragm ruptures the air charge co-mingles with the water and is lost. There was no mention of water at the shrader valve. In fact the gentleman said the tank had not lost its air charge.

    If the iron was getting on the back side of the bladder/diaphragm, that means water would be as well.

    I think it is very possible that the iron sludge has dropped out into the tank, reducing the drawdown capacity. In any case, the iron must be dealt with before a new tank is installed.
  9. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,919
    Location:
    NW Ontario, Canada
    I don't see anyone anywhere suggesting that to be the case so not really sure why you keep bringing it up and in the tone as if you are correcting someone. I suggested that the iron was building up between the bladder and the sides of the tank reducing the drawdown capacity. You seem to both agree and disagree.
  10. valveman

    valveman Moderator Staff Member

    Messages:
    4,425
    Location:
    Lubbock, Texas
    I believe LL is right when he said the iron could be getting between the bladder and the wall of the tank on the “water-side” of the bladder.

    I believe Craig is right when he said the iron cannot get on the backside or “air-side” of the bladder unless the bladder is busted.

    I think the confusion is between the “backside” or “air-side” and “water-side” of the bladder. Straighten this out and you are both correct.

    My problem all along with this set up was using the air injector prior to a bladder tank and having air and iron in the bladder tank. I think everyone is in agreement on this as well.

    Whatever caused it, the tank is not holding enough water and we need to figure out what is causing that.
  11. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,919
    Location:
    NW Ontario, Canada
    The bladder is actually a diaphragm that loosely resembles a sock being rolled inside out. When the tank is empty, the sides of the bladder contact the sides of the tank on the water side. When the tank is full, it contacts the sides of the tank on the air side. Throughout each cycle, like a sock, it rolls inside out and outside in. This rolling back and forth presses the iron against the side of the tank on the water side and it builds up there.
  12. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,919
    Location:
    NW Ontario, Canada
    Another point I'd like to make is that a bladder can be busted and still hold air. The hole can seal when it presses against the side of the tank as it is being drawn down. In fact it can "jack up" the air pressure as water crosses over to the air side but cannot return.

    The often prescribed test to see if water comes out the air valve only holds true when the tank is 100% waterlogged and there is a head of water above the tank. Given that the air valve is at the highest point on most tanks, and that air rises to the top, releasing a little bit of air proves nothing.
  13. valveman

    valveman Moderator Staff Member

    Messages:
    4,425
    Location:
    Lubbock, Texas
    I agree with you on everything except with a good "diaphragm" tank like the Amtrol, the bladder is not supposed to touch the walls of the tank on the air side.
  14. craigpump

    craigpump Member

    Messages:
    891
    Location:
    ct
    I think you misunderstand what I'm saying, we have seen iron build ups inside the liner on Amtrol tanks, which then reduces the drawdown capacity of the tank. The only time I have seen iron on the air side of the diaphragm is when the diaphram has failed.

    I'm not a treatment guy by any means, but he has to deal with iron issue before he puts in a new tank or eventually the same issue will occur. I have seen guys install a short 42 gallon galvanized tank before the Amtrol with a micronizer before the galvanized tank. They plumb the inlet into the middle port and take water out the top of the tank over to the tank T on the Amtrol. Their theory is that the iron will drop out in the galvanized tank which can then be drained off. I personally have never done it.

    As for tone LL, I only give back what I feel I am being given.
  15. gojoe3

    gojoe3 New Member

    Messages:
    68
    Hey , thanks everyone for chiming in.

    Sorry to cause a controversy.
    Now I'm gonna have to use my sawzall to cut the tank and tee apart and then take photos and upload them here for all to see. Once I get the new components in place of course.

    My wife is ready to kill me, for not yet deciding which route to go. Recently, I've been turning the water off at night, before bedtime, so it doesn't short cycle in the AM and wake us. Then when I turn it on in the morning the pump comes on and runs for 15 or 20 seconds, so 2 to 3 gallons of water have gone somewhere, who knows where.

    Oh, yeah, I know this doesn't make any sense, but it doesn't seem to cycle at night, only after 5 or 6 in the morning every 15 mins. or so, I still can't figure that one out.

    Anywho, I'll need to read all your replies again in the morning and try to make a decision. I'd like to get this done before my well pump dies waiting for me. My plumber can probably help me out next week, so I just need to let him know what supplies I need and confirm that they are in stock. I could do it on my own, but it might take me forever because I think I may have ADD, at least that's what my sweetheart says I have and now I'm starting to believe her. She caught me applying weed n' feed to the lawn and then filling the bird feeder, when I told her I was going down to test the air pressure in the tank.

    Over and out
  16. craigpump

    craigpump Member

    Messages:
    891
    Location:
    ct
    Everything you need is readily available at any plumbing/pump supply house in Danbury
  17. gojoe3

    gojoe3 New Member

    Messages:
    68
    Hey craigpump,

    Thanks for your replies. Where are you located?

    I was wondering if you would give me your opinion?

    I have another thread going over at the water softener forum here if you care to chime in

    http://www.terrylove.com/forums/showthread.php?51493-sizing-new-pressure-tank-and-CSV-for-use-with-Clack-air-injector-prior-to-softner
  18. gojoe3

    gojoe3 New Member

    Messages:
    68
    craigpump,

    I'm sorry I did not read this reply in its entirety earlier.

    This seems like a relatively simple solution to keep the iron from gunking up the P tank..

    I wonder if I could use the retention/contact tank Gary Slusser was talking about http://www.apwinc.com/retention_tank.html, at this position in the componentry sequence.
    Or, possibly the Wellmate (UT-40) tank which "LLigetfa" suggested I consider.

    Both of those tanks seem to be able to be drained easily. I don't know which would work better at this location ie. restrict the flow less.
  19. craigpump

    craigpump Member

    Messages:
    891
    Location:
    ct
    I know just enough about treatment to get into trouble. I can recommend a few guys here in Fairfield County that really know their stuff though
  20. gojoe3

    gojoe3 New Member

    Messages:
    68
    That would be great, I'd appreciate it.
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