RO System Boost Pump

[lifeofreilly57]

Greetings
My Sea Recovery centrifugal boost pump failed and i'm tired of fixing it.
It's a terrible design to start with. Its a 1/2hp 120/240vac pump that feeds through the filters to the high pressure pump.
I'm sure there's a much more affordable stainless or plastic bodied pump out there that would work just fine with my 25 gph(600gpd) system. Sea Recovery wants $1300.00 for there's.
Any suggestions?
I'm currently in Grenada, so I'll be shipping in from the US, so anything stateside will be good.

[Pitchondesign]

A good pump is an Oberdorfer 104M Centrifugal Air Conditioning Pump. Pressure max is about 24psi, which is less than the Sea Recovery pump, but more than enough for the watermaker. The Oberdorfer is bronze instead of plastic and has a way better seal. Its not cheap at about $700 street price, but is very reliable.

[lifeofreilly57]

Thanks. I'll look it up.
If the replacement seals are readily available it would work.

[s/v Jedi]

I use the March LC3 pump.
https://www.marchpump.com/pump/lc-3c...ic-drive-pump/

[waterman46]

Google irrigation pumps

[Minggat]

45 years in water treatment here.
“Stainless steel” covers a lot of different alloys. 316 is the most commonly known, but not the usual choice for most manufacturers when the application involves contact with seawater. Duplex seems to the popular choice these days.

But calling your high pressure pump you “boost pump” is what jumps out at me. The configuration you describe seem to be pulling water through your pretreatment filters rather than boosting pressure from from a feed pump.

Suggest you get a small pump to feed the filters, which will make you high pressure pump a “boost pump”.

These high pressure pumps never like to run without a well flooded suction. Industrial applications require a positive pressure at the booster pump suction before they begin ramping up.

[Moontide]

Minggat, I have the same system. he is referring to the pump before the high pressure pump. It is mounted below the waterline and is a centrifugal pump. It is referred to as a boost pump as it "boosts" / positive pressurizes the water before the HP pump since they don't like suction.

[Moontide]

To the OP. Maybe try looking for swimming pool pumps. Higher demand items so maybe better pricing. Just don't know what materials they use.

[Scott Berg]

We have had very good luck with March pumps for that application. I'd think that a 5 series (1000gph) would provide adequate water for your system at a cost of under $400

[Pitchondesign]

March pumps are good pumps, however they are magnetic drive, which is good and bad. The good is there is no seal to leak, the bad is they don't produce much pressure. The pressure limitation means filters need to be changed more often. Centrifugal pumps can produce much more pressure (roughly double), but seals can become an issue and there are many types shaft seals. No right choice, just trade offs.

[Minggat]

Originally Posted by Moontide

Minggat, I have the same system. he is referring to the pump before the high pressure pump. It is mounted below the waterline and is a centrifugal pump. It is referred to as a boost pump as it "boosts" / positive pressurizes the water before the HP pump since they don't like suction.

Thanks for that clarification.

[lifeofreilly57]

Originally Posted by Minggat

45 years in water treatment here.
“Stainless steel” covers a lot of different alloys. 316 is the most commonly known, but not the usual choice for most manufacturers when the application involves contact with seawater. Duplex seems to the popular choice these days.

But calling your high pressure pump you “boost pump” is what jumps out at me. The configuration you describe seem to be pulling water through your pretreatment filters rather than boosting pressure from from a feed pump.

Suggest you get a small pump to feed the filters, which will make you high pressure pump a “boost pump”.

These high pressure pumps never like to run without a well flooded suction. Industrial applications require a positive pressure at the booster pump suction before they begin ramping up.

It's actually a lift pump, sea Recovery calls it a boost pump, it feeds the high pressure pump through the filters.

[Lepke]

Farm supply stores often have a good selection of Ag pumps. 120/240 and 12v. Some are all plastic, so no corrosion.
https://www.northerntool.com/ is a good place to start. I've used several of their pumps. My hp watermaker pump is one of their sprayer pumps. ( I usta farm)
Also try ebay.