Potable water pump ?

[Bowdrie]

Originally Posted by rainforest

Can someone recommend a least expensive potable water pump that has a SMOOTH FLOW - not one that cycles ON / OFF / ON /OFF ...

The terms "Least expensive/Smooth flow/Not constant cycles" are not easy to combine in a single device.
A large accumulator tank together with a well adjusted external pressure switch is about the best "practical" way to achieve reasonable performance without breaking the bank.
For larger boats, (and well heeled owners,) the Groco Paragon pumps in either Junior or Senior models together with Groco's large accumulator tanks are a step, (or 3,) above most systems, but take a sedative before looking at prices.

[Cheechako]

The modern variable speed pumps are the answer now days.

A 1 gallon accumulator will help a lot though with a conventional pump. But it will cycle maybe every minute of pumping or less...?

Without an accumulator tank it will cycle pretty much immediately every time with the water on.

[rslifkin]

I just got a chance to test out my new setup that I put together over the winter. 5.5 gallon accumulator tank and a Jabsco Parmax HD4 pump. Pump pressure switch is set for 40/60 psi (on/off). Takes about 30 seconds of pump runtime to recharge the pressure tank and then the pump shuts off. You get about 1.5 gallons of water before the pump kicks back on and the pressure change as things cycle is gradual enough that you don't notice it unless you're really paying attention to it.