Expansion tank

Discussion in 'Open Loop' started by rtaylor345, Apr 24, 2009.

  1. rtaylor345

    rtaylor345 New Member

    Having trouble with Amtrol exspanion tanks develops leaks after 2 or 3 years is there a better tank to use we have three WX-350 tanks
    Please give me some advise
    Last edited by a moderator: Apr 21, 2010
  2. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Re: Exspansion tank

    Hi and welcome,

    Most all tanks are gauranteed for 5 years if not bought on the gray market. The 5 year thing is a benefit to the customer as a result of the tank wars some years ago.

    well xtroll is still considered the very best, but pricey

    I have had good experiences with well rite.

    Many brand names, but I suspect only a few companies making them all.
  3. Valveman

    Valveman Guest

    Re: Exspansion tank

    Well X Trol is the best. Are these leaks to the outside of the tank, or are the bladders just bursting?
  4. rtaylor345

    rtaylor345 New Member

    Re: Exspansion tank

    They seem to develope a leak to the outside. Seems the bladder developes a leak and they we get a pin hole leak to the outside. Seems like it's just a matter of time after 3 years that they start to develope a leak.

  5. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Water is the universal solvent

    What type of system are the failed tanks on?
  6. Valveman

    Valveman Guest

    Re: Exspansion tank

    The water side of an Amtrol tank is plastic lined with a rubber bladder on top. There is no place where the water can touch metal. When the bladder burst, the water is now in the air chamber side where is can touch the steel, and then it rust through. So your bladder is bursting first, then it quickly rust through the upper side of the tank, which makes sense.

    Bursting the bladder is caused by excessive cycling. Even though you have three tanks, the cycling causes the bladders to bend back and forth until they break, just like bending a wire back and forth until it breaks.
    Eliminating the cycling on and off will keep the bladders in the tank from bursting. Usually when you have this much cycling, you also have problems with the motor, pressure switch, and control box failing too often.

    You can replace all three of those 119 gallon size tanks with a single 44 gallon size tank and a CSV. This will save you a lot of money as those big tanks are very expensive. The CSV will completely eliminate cycling for long term uses of water. The pump will still cycle on when you first turn on some water, but it will not go off until you are no longer using any water. So the pump will cycle on when your heat pump comes on, but will not cycle on and off continually, as it does with just the pressure tanks for control. If your heat pump cycles once or twice per hour, then your well pump will only cycle once or twice per hour, instead of maybe 10 to 20 times per hour as with just pressure tanks.

    The CSV causes the amp draw of your pump motor to be reduced as the flow rate is reduced. Even so, this may still cause the use of a little more energy per gallon pumped, and increase your electric bill a few bucks per month. However, eliminating the cycling has proven to triple, quadruple, or even further extend the life expectancy of the pump, motor, pressure tank, pressure switch, starting relay, starting capacitor, and other components in the pump system. You have to decide if it is worth spending a few extra bucks per month on electricity, instead of replacing a couple of thousand dollars worth of tanks every three years, and purchasing 3 or 4 more pumps than you should.

    If you want to get even more technical about it, you need to determine how many extra square feet it takes to house those big tanks, how much that extra footage cost, and how much you are spending to keep that extra square footage warm.

    I have said this before, as many people have told me, a heat pump can’t save anything and can even cost more to operate than a standard AC/furnace, when you have to replace the pump system often.
  7. rtaylor345

    rtaylor345 New Member

    Re: Exspansion tank

    I hate to sound stupid but what is a CSV. Sound like a switch that turns on the pump on and off as it needs it. The system is a open loop, brings water in to a heat exchanger and dumps it back out. There's an actuating valve that opens and closes according to the temperature of about 58 degrees. If the temp. is below 58 the valve opens, turns on the pump and stays open till the water goes up to 58 or above. This cycle continues 24 hours a days and in the reverse in the Summer for air conditioning. We're an Aquatic Center for membership swimming, swim lessons, swim team and water polo. The inside loop goes to a large Dectron unit a Florida water-to-water heat pump and 5 smaller Florida water-to-air heate pumps. The pump is a 5 HP pump. I've had to replace it once already. We're working on our eighth year. Just to give you a little idea how our system is here. I am a lea person but catch on easily. I do most of the work here on my own. The whole thing was designed by an engineer but I think the 5 HP pump is over kill.

  8. Valveman

    Valveman Guest

    Re: Exspansion tank

    I am not sure how your system is set up but, apparently your 5 HP pump is cycling on and off all the time. A CSV is a Cycle Stop Valve. It controls the flow rate off the pump to match the usage, so the pump stays running, instead of cycling on and off. If when your zone valve is open, it is not using as much water as the pump can produce, the pump normally cycles on and off into the pressure tanks. A CSV would reduce the flow from the pump to match the amount being used, so there is no excess water to fill pressure tanks and cause cycling.

    However, the pump will still cycle on and off when your zone valve cycles on and off. So if your zone valve is cycling open and closed a lot, it would be better if you could adjust the flow rate to make it just stay open all, or at least much more of the time. Then the pump will also stay on all, or more of the time.

    Pumps are designed and prefer to run all the time. Cycling on and off is what kills pumps, pressure tanks, and everything else. If when the zone valve is open the pump stays running until the zone valve closes, then you need to manually regulate the flow to keep the zone valve from cycling. If it is not already, this will probably cause you pump to cycle on and off while the zone valve stays open.

    If varying the flow rate from the pump is your problem, such as a regulated zone valve as described above, or needing more flow when all the units are running, and less flow when only a few are running, then a CSV will stop the pump from cycling. This will make the pump and the tanks last many times longer.

Share This Page