Re: pressure tanks
Posted by Mike on December 27, 2001 at 09:30:18:
In response to Re: pressure tanks
Does it matter when you check the air pressure? Do you check it with the tank at its set shut off, or when it is at the low end and about to kick on? Is the standard pressure on the bladder 40 psi?

Several things could be the cause of uneven water pressure in the home. The well pump provides water under pressure to the pressure tank, only while the pump is running. The pump starts when the pressure gauge drops below a set point (lets assume 18 pounds per square inch {psi}) because electrical contacts close and stay closed until the pressure rises to a set point (lets assume 40 psi). The water pressure is maintained at a constant rate by an air/water diaphragm in the pressure tank that actually uses nitrogen rather than oxygen, which separates the water and nitrogen. The pressure gauge is mounted in the pressure tank on the nitrogen side, and should not release water, but nitrogen. After long periods of use the diaphragm tears and releases the nitrogen into the water piping, which is released when you shower. At that point the gauge has water pressure against it, and reads differently than nitrogen pressure because of a differing coefficient of expansion and contraction at differing temperatures. When water squirts from it, it is a good indicator that the expansion tank diaphragm has ruptured.

: Want more information? e-mail me at

: : How do we know that pressure tank connected to well at home needs replacement/repair ?
: : The pressure valve on top of my welltrol pressure tank has 40 psi pressure but water squirted from it, not air
: : as I had expected. Is that normal?
: : The water pressure is uneven in my house. What could be the problem? Thanks.

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