Originally Posted by Java
No idea on sizing them, but the expansion tank just makes the pump not needed for the first 1.75 gallons or whatever till the pressure drops. What pressure are you running on the air side of it? FWIW its supposed to match the delivery pressure.
I dont have room for a two gallon tank..... Maybe not even the small accumulator....
Right. It just increases the time between the low pressure "on" and high pressure "off" set points. The pump is positive displacement. With only the pipes for capacitance in the system, the pump can bang between the set points while trying to put out more flow than your faucet is taking. The accumulator just takes the extra flow and stores it.
The instructions said to set the bladder within 2 psi of the delivery pressure. My pump is supposed to make 50 psi, according to the specs sheet. In reality, it's more like 35 or 40 psi. I set the bladder based off the high shut off pressure. Guys say you can play with the bladder pressure to get the most capacity possible. I kind of set it and forgot about it. lol