Watermaker maintenance, am I missing something?

[Badsanta]

Tillie, I would like to do that. How far from the train station are you?

[Tellie]

Originally Posted by Badsanta

Tillie, I would like to do that. How far from the train station are you?

Amtrack or TriRail? Both stop at the Hollywood station, and that's about 10 minutes from the shop. Shoot me a PM with your contact info and I'll send you info on the class.

Halden Marine Services | Marine Watermakers, Solar Panels, Wind Generators

[mitiempo]

Originally Posted by Monepit

I'm very new to water makers but you say output in fine in freshwater. All I've read is that you should never use them in fresh water.

Many watermakers need the output lowered in fresh water to protect the membrane. Dial it back to the designed output, somewhere around 200 psi.

With a Spectra no adjustment is needed - they are self regulating in fresh or salt water.

[Sailormantx]

Tellie I wish I could make that class you are offering, it I will be sailing at that time. Found a source to replace o rings and a routine service kit for the HP manifold. Hope that's it, the $1300 manifold rebuild kit is not in the budget at this time. I agree, think that pulsation in the pump output may be the culprit.

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[CdS2 Roland]

Hello,
I don't know wich brand of watermaker you have, but reverse osmosis membranes will be destroyed if you use freshwater under pressure. You can flush your system with freshwater, but high pressure pump must be shut off. The freshwater must just be pushed through your system by the waterpump.

Have a good day

[Sailormantx]

Originally Posted by CdS2 Roland

Hello,
I don't know wich brand of watermaker you have, but reverse osmosis membranes will be destroyed if you use freshwater under pressure. You can flush your system with freshwater, but high pressure pump must be shut off. The freshwater must just be pushed through your system by the waterpump.

Have a good day

Not true! They can only be damaged if the pressure is not regulated down to accommodate the lesser salinity to maintain the designed output of the system, in my case 8 gph. This is not conjecture, it is from the manufacturer, Offshore Marine. Years of experience running this machine in fresh and brackish waters as well as the ocean have also proven it to be a safe practice.

Sent from my K013 using Cruisers Sailing Forum mobile app

[mitiempo]

Originally Posted by Sailormantx

Not true! They can only be damaged if the pressure is not regulated down to accommodate the lesser salinity to maintain the designed output of the system, in my case 8 gph. This is not conjecture, it is from the manufacturer, Offshore Marine. Years of experience running this machine in fresh and brackish waters as well as the ocean have also proven it to be a safe practice.

Sent from my K013 using Cruisers Sailing Forum mobile app

Correct.

With Spectra there is not a need to adjust thew flow as they are self regulating in water of any salinity.

[nknowland]

I am going to jump in on this thread as it's relatively current.

We used our new WM for one year, with no problems. It's a component system --10 gph, 12v booster pump and 120v high pressure pump, powered by Honda2000 generator.

We were off the boat for 2 years and pickled the WM according to mfg instructions (sodium metabisulfate).

Back in the Bahamas now and output is down to 6 gph at 700psi instead of the 10gph we got previously at 700psi. TDS starts at 245 but climbs to 295 after one hour running and up to 385 after 4 hours.

Pumps seem to be running fine. Not hot. Not leaking. No air bubbles.

Is it the membrane???? Any and all ideas welcome.

Thanks

[JstaRebel]

Originally Posted by CdS2 Roland

Hello,
I don't know wich brand of watermaker you have, but reverse osmosis membranes will be destroyed if you use freshwater under pressure. You can flush your system with freshwater, but high pressure pump must be shut off. The freshwater must just be pushed through your system by the waterpump.

Have a good day

Whomever told you this does not know what they are talking about. ALL Industrial desalination systems are flushed using permeate water diverted into the feedwater side and flushed using the HP pumps. ALL OF THEM!

[JstaRebel]

Originally Posted by nknowland

I am going to jump in on this thread as it's relatively current.

We used our new WM for one year, with no problems. It's a component system --10 gph, 12v booster pump and 120v high pressure pump, powered by Honda2000 generator.

We were off the boat for 2 years and pickled the WM according to mfg instructions (sodium metabisulfate).

Back in the Bahamas now and output is down to 6 gph at 700psi instead of the 10gph we got previously at 700psi. TDS starts at 245 but climbs to 295 after one hour running and up to 385 after 4 hours.

Pumps seem to be running fine. Not hot. Not leaking. No air bubbles.

Is it the membrane???? Any and all ideas welcome.

Thanks

I would suggest looking at your flows for the permeate and concentrate as it seems like you are over fluxing your membranes. The recovery rate for a small watermaker should be around 35-40%. 45% is maximum recovery for SWRO membranes. % Recovery = (Product flow rate ÷ Feed flow rate) × 100.

Hope this helps.