Why do watermakers fail?

[Cpt Mark]

As I prep to go cruising I am thinking about converting one of my 70 gal water tanks to a fuel tank. Tank is aluminum. I have 55 gallon fuel tank. I will probably to choose another option but in the discussions about this idea the topic of watermaker failures came up. I've heard/read where people out cruising have them fail. Do they fail for generally a few certain reasons? Pump failure, high pressure hose failure, etc?

I have a very old ac driven Village marine tech watermaker. New membranes

Are there spare parts I should bring?

[Fuss]

You want the feed pump and pressure pump as low down as possible so, there is nearly no work for the feed pump to do to get water to the pressure pump. Bring a spare high pressure hose from the high pressure pump and spare seals for the high pressure pump…these can be changed in a few hours when the pump is on the workbench. New membranes, good, more than one, then design a method to bypass one of the membranes should it become faulty. Bring some seals for the pressure vessel.

[Cpt Mark]

Originally Posted by Fuss

You want the feed pump and pressure pump as low down as possible so, there is nearly no work for the feed pump to do to get water to the pressure pump. Bring a spare high pressure hose and spare seals for the high pressure pump…these can be changed in a few hours when the pump is on the workbench. New membranes, good, then design a method to bypass one of the membranes should it become faulty. Bring some seals for the pressure vessel.

Thanks Fuss. Greatly appreciated.