On 8/2/2014 2:11 PM, Michael wrote:
> I've posted this to alt.home.repair, but in case that doesn't work out, I hope maybe some of you might know.
>
> I'm changing out the water pressure tank, but I don't have a shut off valve from tank to well to drain the tank. If I turn off the breaker to the well pump, will this effectively shut off the water so I can drain the tank and replace it? Help much appreciated.
>
This was a task that as a child that I got to do regularly as we had to
craw under the house to do it.
I assume this is your system: There is a pipe from the well to the
pump. The pump puts the water into a storage tank, where pressure is
maintained to provide water to the outlets in the house without the pump
activating every time a valve is opened.
While it is nice to have a valve on the pressure tank to release the
pressure at the tank, you can also relive the pressure by opening a
valve in the house and let it run until no water comes out. When the
water stops running the pressure on the tank should be near zero.
There should be a valve low in the tank to drain the water from the tank
if not you may be able to siphon it using a drain lower than the
pressure tank.
If there is no pressure valve, or drain valve on the tank, you may have
to drain as much as will come out when you open a valve in the house to
remove the pressure. You will then have to remove the tank partially
filled wit water. (I would definitely make sure both are on on the new
tank.)
You do not want the water of in the tank to drain back into the well,
that is a safety design to prevent the well from becoming contaminated.
There is a back flush valve between the pump and the well that will
prevent the water going back into the well. There may be a double back
flush valve, or one only at the foot of the pipe deep within the well.
I can not believe that a pressure system does not have a pressure relief
valve, I believe that is another safety issue.