Boost Pump Recommendation please (Watermaker)

[SailingAdrift]

This May be a stupid question, but even if you install the pump below the waterline if the panel with Y-valve is above the waterline, you run into the same problem with a non-self priming pump, correct?

[SV THIRD DAY]

Originally Posted by SailingAdrift

This May be a stupid question, but even if you install the pump below the waterline if the panel with Y-valve is above the waterline, you run into the same problem with a non-self priming pump, correct?

It's depends on what type of self priming pump you are using. The Boost pump used by Cruise RO for example can handle a 7ft head lift above the waterline. However some undersized Centrifugal pumps supplied with some water makers would not be able to handle the head lift or the prefikters or valves being installed much above the water line.

[SailingAdrift]

Originally Posted by SV THIRD DAY

It's depends on what type of self priming pump you are using. The Boost pump used by Cruise RO for example can handle a 7ft head lift above the waterline. However some undersized Centrifugal pumps supplied with some water makers would not be able to handle the head lift or the prefikters or valves being installed much above the water line.

In the diagram I'm working from water comes in from your through hull, makes its way through the sea strainer and then up above the water line to a y-valve, and then back down below the water line to the boost pump. Will my Oberdorfer 170M handle that or would it need to be installed before the y-valve? If it's installed before the y-valve then it can't be used for flushing and pickling..

[Statistical]

Originally Posted by SailingAdrift

In the diagram I'm working from water comes in from your through hull, makes its way through the sea strainer and then up above the water line to a y-valve, and then back down below the water line to the boost pump. Will my Oberdorfer 170M handle that or would it need to be installed before the y-valve? If it's installed before the y-valve then it can't be used for flushing and pickling..

It is going to depend on the specifics of your panel and the connections. From what you describe yes you would need a self priming pump (or a way to manually prime which would be a pia).

However other panels are plumbed differently.

In this example a non-self priming pump could be used if below the water line.



(Note I think having the pickling valve after the boost pump is dumb. If I were plumbing this I would put it before the boost pump so the boost pump could be used for picking as well)

[SailingAdrift]

So what pump is pulling the cleaning storage fluid in this example? Seems like you could get a nice flush with this configuration by dual utilizing the pressurized water pump, but will it draw the pickling solution?

[Statistical]

Originally Posted by SailingAdrift

So what pump is pulling the cleaning storage fluid in this example? Seems like you could get a nice flush with this configuration by dual utilizing the pressurized water pump, but will it draw the pickling solution?

Yeah I think putting it there would be dumb. You would need some sort of temporary pump for pickling.

Personally I would in that example above move the pickling three way valve to be between the sea strainer and boost pump. Then the boost pump is normally used to boost raw water and when winterizing flip the valve and have it boost pickling solution from a bucket.

The way the diagram is drawn it "works" just seems less convenient for no gain.

[SailingAdrift]

Originally Posted by Statistical

Yeah I think putting it there would be dumb. You would need some sort of temporary pump for pickling.

Personally I would in that example above move the pickling three way valve to be between the sea strainer and boost pump. Then the boost pump is normally used to boost raw water and when winterizing flip the valve and have it boost pickling solution from a bucket.

The way the diagram is drawn it "works" just seems less convenient for no gain.

That would definitely work, but would sacrifice the convenience of having everything at the panel. I guess you don't pickle often so removing the floor of the pilot house that infrequently wouldn't be that inconvenient.....

[SailingAdrift]

Any disadvantages to using pex as the input hose to the high pressure pump?

[s/v Jedi]

Originally Posted by SailingAdrift

Any disadvantages to using pex as the input hose to the high pressure pump?

PEX doesn’t dampen the vibrations from the HP pump much. I would use a flexible coupling to connect the PEX to the pump inlet.

[SV THIRD DAY]

Originally Posted by SailingAdrift

In the diagram I'm working from water comes in from your through hull, makes its way through the sea strainer and then up above the water line to a y-valve, and then back down below the water line to the boost pump. Will my Oberdorfer 170M handle that or would it need to be installed before the y-valve? If it's installed before the y-valve then it can't be used for flushing and pickling..

Why stick to a diagram that causes you problems?
Don't.
Put the 3-way selector valve below the water line and remove the potential for problems. Located the 3-way valve somewhere on the suction side of the Boost Pump and problem solved.

Cheers