Originally Posted by sailingunity
A few months ago I replaced a Jabsco
2GPM pump with a 3GPM pump with integrated bypass valve. This was done in an attempt to stop the pump from cycling so much, as I had tried adding an accumulator to the 2GPM pump and it still cycled too much.
The 3GPM pump still cycles on/off about every 1 second, this is with the accumulator still installed in the system. I really thought the bypass valve would almost eliminate the cycling, it came with no instructions.
According to online literature no accumulator is necessary, I thought it wouldn't hurt, but do I need to remove that to make the pump work
You didn't specify what kind of accumulator tank you have.
Some of the little plastic ones are hardly more than a pulsation/water hammer dampener.
The better ones use a diaphragm/bellows/bladder, whatever, to separate the air/water sections.
Over time, in a tank without that separation the air charge will dissolve into the water
Success with an accumulator relies upon a static air pressure charge that is ~1/2 the psi of the shut-off point of the pump.
Even the best tanks
over time can leak their air charge out thru the Schrader valve, so it's something to monitor
from time to time.
Some of the pressure switches that are built-in to pumps have too close of a setting between on/off.
Best results are obtained with a remote
switch like a "Square D" or "Furnas", where the cut in/cut out pressures are adjustable.
The "Bypass valve" is just a tiny passage/device, connecting the inlet and outlet together that "dumps" the pressure behind the outlet valve in the pump so that when the pump comes on it doesn't have to start against the cut-out pressure, it's similar to an "Unloader valve" in an air compressor
The pumps that advertise "No accumulator tank necessary" are by design made to cycle endlessly, they must, as water
But, set-up properly they work just fine with a tank, at least the Flo-Jet and Shure-Flow ones I've installed did.