Hooking up larger pressure tank...

Discussion in 'Pumps and Tanks Well Forum & Blog' started by whitehawk20, Apr 8, 2008.

  1. whitehawk20

    whitehawk20 New Member

    Messages:
    3
    I have an existing pressure tank hooked up after the well service line. It then goes to a tee, one direction to my irrigation system and the other to my house line. The problem is when the irrigation runs the pressure switch cycles the pump to come on every 45 seconds or so. what i plan on doing is getting a larger pressure tank do the under sizing of it at the time of construction, but i want to relocate the pressure tank to my garage which is located on the other side of the house, approx 50 feet away from the existing pressure tank location. My questions are:
    1. If i move the pressure tank to the new location away from the irrigation line, will the pressure tank still function properly, assuming there is a check valve before the well/pump service line?
    2. Will the pump continuously run since the pressure tank is now not prior to the irrigation outlet line as it presently is hooked up?
    My assumption is the pressue will be equal throughout the system and the pump will only come on once the pressure drops no matter if it is before the irrigation hook up or after. I have pictures to help explain but am not sure how to post.
    Thanks
    Bob
  2. valveman

    valveman Moderator Staff Member

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    Location:
    Lubbock, Texas
    Even if you double the amount of pressure tanks, it will only change the cycling time from 45 seconds to 90 seconds. If you install a Cycle Stop Valve before the pressure tank or any tees off the main line, you won't need another tank and the pump will NEVER cycle while the irrigation is running.
  3. whitehawk20

    whitehawk20 New Member

    Messages:
    3
    What is the CSV going to do? Will it keep the pump just running while the irrigation is on?
    The main reason for moving the pressure tank is the pressure switch is making a clicking noise when it turns on/off and it is under our bedroom in the crawl space, hence the reason a larger tank is assumed to be needed due to the cycling every 45 to 60 seconds. so what we want to do is move the pressure tank and switch into the garage no matter what. I guess does it matter if the irrigation connection is prior to the pressure tank or should it be after the pressure tank? and what will the CSV due to the cycling?
  4. cacher_chick

    cacher_chick Test, Don't Guess!

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    don't overlook simple solutions

    Don't know what kind of irrigation system you are running... for a home system it would be easier and cheaper to increase the amount of water you are using to closer match what the pump output is. Adding another sprinkler head or two is all it takes on some systems.
  5. valveman

    valveman Moderator Staff Member

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    4,426
    Location:
    Lubbock, Texas
    A Cycle Stop Valve will stop the pump from cycling. If you could run enough sprinklers to keep the pump from cycling, that would also be OK. However, you would be using all the water your pump will produce for the irrigation. Then if you need water in the house while the irrigation is running, the pressure will be very low.

    Moving the tank so you don't HEAR the cycling may not be a good thing. Cycling is what will destroy your pump in short order. You need to know when the pump is cycling so you can turn on more sprinklers or turn the pump off before you destroy it.

    A CSV will make your pump match the amount of water you are using. In this way the pump doesn't make excess water to cause the cycling. I would use a CSV to eliminate the cycling, then you will not be hearing the noise or destroying your pump.
  6. whitehawk20

    whitehawk20 New Member

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    3
    one more quick question about the CSV. Knowing the cycling of the pump will some how damage the pump, but won't the CSV actually produce a back pressure on the pump not allowing it to fully pump but actually choking off the flow rate which may in fact burn up the motor? Just wondering?
  7. valveman

    valveman Moderator Staff Member

    Messages:
    4,426
    Location:
    Lubbock, Texas
    The CSV just makes the pump think it is in a deeper well so it can't pump as much water. It will never allow the pump to put out less than 1 GPM, which is plenty to keep the pump nice and cool. The back pressure is a good thing. Back pressure is what keeps the pump from cycling. Cycling is the cause for MOST failures of pumps and motors.

    Pumps are made for continuous duty. They will last longer if they run 24/7 than if they cycle on and off. Much like a diesel engine, starting is what hurts them, not running.
    Last edited: Apr 11, 2008
  8. Bob NH

    Bob NH In the Trades

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    Location:
    New Hampshire
    If you add volume (GPM) to the irrigation system, and maybe increase the shutoff pressure setting to 60-65 psi, you should be able to cause the pump to run continuously when the irrigation system is operating.

    If you tell us the size of the tank, the GPM of the pump, and the start/stop pressure settings of the switch, we can estimate how much more flow you need to add to the irrigation system or how much you should adjust the pressure.

    Now to address the question of what happens when you need household water. If the pressure when running "irrigation only" is about 60 psi with a 65 psi shutoff pressure on the switch, then you will be able to draw a significant amount of household water before the pressure drops down to 35 psi which is usually plenty for domestic use.

    Modern shower heads contain flow regulators that have nearly constant flow rate (about 2.5 GPM) over the usual range of operation so you will see little difference. The effect on toilets, dishwashers, washing machines, and faucets is negligable and probably not noticable.
  9. valveman

    valveman Moderator Staff Member

    Messages:
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    Location:
    Lubbock, Texas
    As I have said before, if you match the irrigation system to the pump, you don't have any pressure left for the house while the sprinklers are running. You will certainly notice the difference between 60 and 35 PSI. Compared to 60 PSI, at 35 PSI, you effectively think you are out of water, and you basically are.

    Plus, if taking a shower brings the pressure down to 35 PSI, your sprinklers are no longer reaching where they should either.
  10. Gary Slusser

    Gary Slusser That's all folks!

    BobNH, I doubt that you have done what you suggest to people that they do.

    And unless you say that you're comments and statements are "for purposes of illustration", most of the people here asking for advice will be taking your statements as fact; to their detriment.

    That is confusing along with not being helpful and can cost people substantial money while not improving their situation or quality of life until they spend more time, effort and money to git'er done.
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