On 8/14/2018 2:37 PM, Arlen Holder wrote:
....

The pump appears to have only one purpose, which is to boost the water
pressure of the bladder from ambient pressure to about 75 psi.

I've seen these bladders everywhere where I live, so, they're pretty common
(every single home has one).

It's odd that someone said the "water tank" is pressurized, as that would
be astoundingly crazy to pressurize a 10,000 gallon set of tanks when all
you need to do is pressurize these little 4-foot tall bladder tanks.


Well, if one has well capacity that is sufficient for demand, the
"normal" way a system is configured is that the pressure tank _is_ the
pressurizing element for the distribution system when the pump isn't
running and there is no secondary booster pump.

The air pressure in the tank is set at -2 psi relative to cutout
setpoint when the tank is empty and the bladder/diaphragm is then
compressed/stretched to produce exit water pressure on demand.

The system here operates 40-60 psi with an 80 gal pressure tank
capacity; when the pressure drops below the low cut-in, the pump kicks
on and supplies both demand and refills the tank to pressure at which it
cuts off and the cycle starts over...

With a system such as yours you have an extremely large reservoir
because (apparently) the well can't keep up to demand and so must be
able to pump into the holding tank whether there's current demand or not
in order to have sufficient volume on hand for demand.

Or, demand rate could possibly be very high if one were doing
large-scale irrigation or the like, but normal residential demand plus
several hundred head of cattle doesn't tax this well at all even on 100+
F days when they hit the water pretty hard.

Granted, it would make no sense to try to pressurize the whole system
under that operating scenario, but as noted, while that's what's common
where you are, overall that's a relatively uncommon installation type;
definitely not what I was thinking of when we started!

As for how good a seal; 75-100 psi isn't all that much to try to seal;
also note and check -- given the age of the system there's at least a
reasonable chance that pressure gauge isn't working at all but is frozen
up, particularly if it's not an oil-filled one but direct.

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