Draining pressure tank

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swimmer_spe

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I am ready to redo the plumbing from my pump to the rest of the house. My issue is the pressure tank does not have a separate isolation valve. So, my plan is to drain it down and clean it out. However, I am concerned that the pump will loose it's prime. I am also concerned with the sludge from the bottom contaminating the system. If I isolate the system, and shut the pump off, can the tank be drained without loosing suction and without contaminating the system? I will be changing out all the lines.
 

bud16415

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You should have a foot valve at the end of the pipe in the well and that acts as a check valve holding the line to the pump full of water. The tank can be just a tank and use air over water to store pressure or it can have a bladder in there that keeps the air/water separated. You can drain it without problems and with the air over water type you need to add air from time to time and one way of doing that is to open the tank to air and then drain it the pump., close it to air and start.
 

swimmer_spe

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You should have a foot valve at the end of the pipe in the well and that acts as a check valve holding the line to the pump full of water. The tank can be just a tank and use air over water to store pressure or it can have a bladder in there that keeps the air/water separated. You can drain it without problems and with the air over water type you need to add air from time to time and one way of doing that is to open the tank to air and then drain it the pump., close it to air and start.
I draw water from a lake. AFAIK there is a foot valve. There is no air valve. It does have a bladder.
 

ajaynejr

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A pressure tank with a bladder must have an air inlet valve somewhere, usually at the opposite end from the water pipe connection. Possibly covered with a screw on plastic cap or escutcheon or trim piece.

During normal system operation, several gallons of water go into and then out of the pressure tank during every pump cycle between pump restarts. This means that very little sludge or sediment will accumulate in the pressure tank at the outlet pipe.

If you do not have an isolation valve just under the pressure tank and you wish to add one then you must depressurize the system by opening faucets, not necessarily depressurizing a bladder tank using its air valve, before you can install the isolation valve. Otherwise you will get lots of water all over the floor. The isolation valve must never be closed while the pump has power.
 
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swimmer_spe

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A pressure tank with a bladder must have an air inlet valve somewhere, usually at the opposite end from the water pipe connection. Possibly covered with a screw on plastic cap or escutcheon or trim piece.

During normal system operation, several gallons of water go into and then out of the pressure tank during every pump cycle between pump restarts. This means that very little sludge or sediment will accumulate in the pressure tank.

If you do not have an isolation valve just under the pressure tank and you wish to add one then you must depressurize the system by opening faucets, not necessarily depressurizing a bladder tank using its air valve, before you can install the isolation valve. Otherwise you will get lots of water all over the floor. The isolation valve must never be closed while the pump has power.
My piping system at the pump has a valve right at the punp that I can put a garden hose on and drain it. I have isloation valves on the filteing system, so I will only be draining the tank.
 
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