Booster Pump Pressure

[guitarandy]

I have a booster pump for my IBA spot free water. My Laserwash requires 30 psi at the inlet. My booster pump delivers up to 50 psi. the pressure switch on the booster pump is in at 30 and out at 50. I would like to increase the cut in pressure but that will also increase the cut out pressure to above what the pump will produce.
1- Has anyone seen a pressure switch that has a cut out that is 10 psi above the cut in?
2- Is there a timer that I could use to cut the pump off if my cut in pressure is increased?

 

[MEP001]

It sounds like you're talking about the spot-free production system and not the delivery. The delivery pump would draw from a storage tank with no pressure and wouldn't have a pressure switch. Can you upload some photos of what you're talking about?

 

[guitarandy]

My Laserwash has a gravity fed fresh water tank connected to the main pump intake manifold. It also has a spot free water inlet and valve connected to the the same manifold. When the system calls for spot free water the spot free inlet valve opens and lets spot free water from a booster pump/pressure tank enter the main pump intake manifold. The pressure of the spot free water coming in to the manifold has to be great enough to overcome the pressure of the fresh water gravity fed holding tank on top of the unit.

Thus I need a little over 30 psi from my spot free booster (I would like 35 psi) but when I adjust the spot free booster above 30 psi it can't generate enough pressure to shut off at over 50.

 

[boywonder]

On my laser we don't have a pressure switch. The signal to the contactor is sent when it calls for spot free. Really you need to make sure you have more flow then pressure even though the pressure switch is approx 5psi. We were having issue with low flow to that valve. Went to 1 1/2" hose and upgraded to the new valve they recommend. No problems since.

 

[guitarandy]

I went from a 1 inch hose 4 foot long from the booster to the inlet valve, to a 1 1/4 as PDQ recommended. I haven't sprung for the other valve yet. I think that it would work if I could just raise the cut in pressure of the booster.

 

[MEP001]

I think I understand now, you're using a solenoid to control the RO flow and a pressure switch to control the pump. boywonder has the right idea - using the same circuit to control both the solenoid and the pump makes more sense.