Turning your watermaker pump into a pressure washer

[heintje23]

Did anybody try this already? Is it possible with a cat pump? It has two entries for fresh water and two high pressure exits. I was thinking about installing an unloader valve on the freshwater connect side.

[Terra Nova]

Surely there are better ways to provide high flow wash-down volume without wearing out your expensive watermaker pump.

[heintje23]

Can you wear out a cat pump? How many hours would that take?

[Cheechako]

I don't know why you couldn't. Three way valve after the output on the pump and a pressure relief valve?

[HopCar]

I suggested that to a friend who has a big watermaker but he said he didn't need a high pressure wash down. I don't see why it wouldn't work.

Isn't the high pressure side of a watermaker salt water?

[Cheechako]

Yes the output pump would be putting out salt water washdown. My pressure washer is 2500 psi, so I suppose the watermaker pump would be a lower output. It seems to be dependent on the orifice size used on the nozzle... or the needle valve in the case of the water maker. I think the pumps are rated for a max pressure but alot of the pressure is created by restricting the flow right?

[heintje23]

I did some research and if I install an unloader valve i should be good. This is a bypass and pressure regulating valve. I can plumb the fresh water to this side of the cat as it has two sides. Only need an extra valve on the outlet to the ro membrane