Watermaker Boost Pump recommendations.

[ksanders]

Here is my challenge...

I have a piston pump watermaker, originally made by Cruise RO many years ago.

It uses off the shelf components, so there is no engineering mystery there.
In order to operate properly it needs positive pressure to the high pressure pump, and this is supplied using a boost pump.

Here is the problem...

The boost pump does not need a lot of pressure, and it needs around 2.5 GPM.
It needs to be able to run continuously, and it needs to be self priming.
120V AC or 12V DC it doesn't matter to me, either one will work.

The original design used a marine potable water pump, and a bypass valve. You would turn on the pump, and adjust the bypass valve for 20 or so PSI into the feed pump, and you would adjust the valve as your pre-filters became loaded up with debris.

Then we switched to using the Jabsco Vflo variable speed pumps and they worked pretty well, with lets say decent reliability, but Jabsco has discontinued that series because it had reliability problems. Now they have a new variable speed pump.

The problem with these solutions is the pumps are not continuous duty. In order to get a decent life we had to mount a DC fan blowing on them to dissipate the heat. Not a perfect solution but it worked.

But... the Vflo is discontinued. So we need a solution.

Has anybody tried using for example the shurflo self priming Air conditioner pump as a boost pump on their watermaker?

Any other ideas out there???

 

[Nick F]

The boost pump does not need a lot of pressure, and it needs around 2.5 GPM.
It needs to be able to run continuously, and it needs to be self priming.

Any chance of mounting the pump below the water line? Then you could use a centrifugal pump which has otherwise ideal characteristics.

 

[Larry M]

I have used a Johnson and a March pump on 2 different systems. Both were mag drive and 110 vac. Johnson does make a few 12vdc pumps. They aren’t cheap but I never had any failures.

 

[ksanders]

Thinking about this...

When I pickle the system there is a chance on getting air into the system, but not when I change the pre-filters since they are on the pressure side of the pump.

Yes the pump is below the water line.

But... on the other hand the high pressure pump will help prime the system if need be by creating a bit of suction.

Question... Do the March AC pumps have enough pressure to overcome the resistance of the pe filters?
What kind of pressures do you see on the output of an AC pump?

 

[NoRain]

That’s what I have done. Just put an extra outlet on the raw water manifold for the AC units. Works perfectly, but it is a beast of a pump. I just replaced it with the same unit for ease of replacement, but had them put the larger impeller in it. (The Scot pumps have several “versions” ie different capacities, differing by only the impeller size). Current pump is 35 gpm which is more than I need for HVAC, but the extra capacity provides more boost pressure by the very nature of the large flow. So I’m seeing regularly 12 psi at my HP pump, which is more than ample, but provides the extra to deal with the filters as they clog. Plus I have an extra filter in my pre-filter setup. I have a coalescing filter like they have on bilge scrubbers, to remove any hydrocarbon. That allows me to be much less picky about where I make water. But it is an extra filter to push through so the extra pressure comes in handy.

 

[O C Diver]

You can get AC centrifugal pumps that will lift to 25' (10+ PSI). On my system the anchor wash down pump (diaphragm) was teed at the AC pump, so clearing the air out of the system was simply running the diaphragm pump.

In a different direction, if you have space for a bladder tank, use a diaphragm pump. My domestic water pump was a washdown pump (6 GPM at 60 PSI). If you could find a bladder tank that could handle salt water, you could probably get a 50% duty cycle every couple of minutes and no issue with the pre filter pressure.

Ted

 

[mvweebles]

Maybe try the Seawater Pro boost pump.

Boost Pump, Two stage, 30 psi, 500 GPH | SeaWater Pro

NEW 2 stage 30 psi 500 GPH, Boost Pump 12 to 28 Volt Brush-less, fully submersible, water cooled. This pump is included with every new SeaWater Pro water maker. Watch the following videos for instructions and more information. Installing a boost pump video. Running and adjusting the boost pump...

seawaterpro.com

I have the CruiseRO setup and it's a kluge with a fan mounted to cool the body. They use off-the-shelf parts but in my opinion, CRO is resting on their laurels and not the company they used to be. I very much regret buying from them - the bizarre fan cooled pump is just another example.

Peter

 

[ksanders]

Maybe try the Seawater Pro boost pump.

Boost Pump, Two stage, 30 psi, 500 GPH | SeaWater Pro

NEW 2 stage 30 psi 500 GPH, Boost Pump 12 to 28 Volt Brush-less, fully submersible, water cooled. This pump is included with every new SeaWater Pro water maker. Watch the following videos for instructions and more information. Installing a boost pump video. Running and adjusting the boost pump...

seawaterpro.com

I have the CruiseRO setup and it's a kluge with a fan mounted to cool the body. They use off-the-shelf parts but in my opinion, CRO is resting on their laurels and not the company they used to be. I very much regret buying from them - the bizarre fan cooled pump is just another example.

Peter

I won't disagree that the Cruise RO setup is a bit abnormal, and I am not a fan of the boost pump they offer but it works. In fact I'm using it right now, and use it pretty much every day.

Still I would rather have a pump that is rated for continous duty.

Perhaps I'll try the March AC pump.

But... Jabsco has a new generation of variable flow pumps called the sensor max 2. I'm thinking of trying one of these out both on the water maker and my potable water system. If it works then I could reduce my spare count. The reason I might try it on my potable water system is that I do not like the pulsating pressure or low pressure you get with a on off pump. You either pick a pump that is a lower flow rate so that when you turn on a faucet or the shower it runs continuously at a lower pressure, or you pick a higher flow pump that cycles when a faucet is on.

 

[mvweebles]

Kevin - if you get the Jabsco variable speed pump, please post updates. I assume the pressure tank is not needed with it?

I don't think watermakers require much boost. I forget what pump I'm using but it's rated well under what CRO specifies. I had an older small watermaker that I replaced with the CRO 30gph one. They sent the wrong voltage boost pump so I used the old one and it worked fine (well, as good as the new Rube Goldberg contraption with the fan). The March one should be fine - its enough pressure to lift over 10-feet.

Peter

 

[slowgoesit]

Kevin, I second Peter's recommendation on the SeaWaterpro boost pump. It is NOT self priming (as in able to lift tall buildings up to30' or so), but if mounted below the water line, it will pull water just fine to get the pump started.

Boost Pump, Two stage, 30 psi, 500 GPH | SeaWater Pro

NEW 2 stage 30 psi 500 GPH, Boost Pump 12 to 28 Volt Brush-less, fully submersible, water cooled. This pump is included with every new SeaWater Pro water maker. Watch the following videos for instructions and more information. Installing a boost pump video. Running and adjusting the boost pump...

seawaterpro.com

12vdc to 29vdc, 500 gph, and continuous duty rated. A bit pricey at $245.00, but Mike at SeaWaterpro has never steered me wrong. Other's however . . . . yeah, we'll not get into that in this family program . . .

 

[Nick F]

If you want reliability go with a 110VAC pump, centrifugal impeller, magnetic drive. No shaft seal. No electronics.

March Pump

US Manufacturer Of Centrifugal Sealless Magnetic Drive Pumps for Chemical, Industrial, Medical, Marine, Solar, and OEM applications.

www.marchpump.com

I see that Defender offers this same brand. Its a more expensive pump sold into the industrial market but will far outlast the other options.

 

[motion30]

Mike at sea water pro Has engineered and is sauce A Continuous duty double pump that has a restatstat hat lets you control The pump speed and therefore the pressure. Turns out it has been a reliable trouble-free pump

 

[ksanders]

Great advice guys!

I have on order two of the new Jabsco variable speed pumps, and will post how it works out.

 

[ksanders]

Kevin - if you get the Jabsco variable speed pump, please post updates. I assume the pressure tank is not needed with it?

I don't think watermakers require much boost. I forget what pump I'm using but it's rated well under what CRO specifies. I had an older small watermaker that I replaced with the CRO 30gph one. They sent the wrong voltage boost pump so I used the old one and it worked fine (well, as good as the new Rube Goldberg contraption with the fan). The March one should be fine - its enough pressure to lift over 10-feet.

Peter

Good morning Peter

We installed the new Jabsco vairable flow, Sensor Max 2 yesterday on the potable water system.

So far, the pump is perfect, providing an even pressure with no surging.

Time will tell how reliable it is but right now it is working great!

 

[ksanders]

well, in looking for a pump for my house in Mexico I ran across this, which I think would be perfect for a watermaker boost pump.

It's a self priming, run dry protected variable speed pressure pump.

Grundfos SCALA2 3-45 Constant Pressure Boost Pump - 115V

SCALA2 incorporates integrated speed control which allows maintaining a perfect pressure in the taps.

uswatersystems.com