ive just spent over 1 hour reading all the pages and posts, .........I have to say, im still no wiser. Whilst i realy appreciate everyones shared input and experience, I cant see the woods for the trees and a lot of advice often clouds the issue with so many variations.
Im intending to make a machine which will run directly off the gen engine
shaft via a pulley. The gen is run @ 2 hours per day at sea to charge batteries and provide 240 ac for other uses (sounds extravagant i know but as yet, im not responsible for that) So with the gen running anyway, it makes sense to use the engine
to directly power the water
maker pump. Direct useage of engine power is most efficient and wont contribute to damaging batteries with high loads. The genset and main engine are side by side and i hope to make it possible to use either engine in the event of one breaking down on a long passage
During the 2 hour run time, i want to make @ 40 uk galls/ 200 lts. Cant see much point making more just to waste it. maybe the genset run time can be cut to 1 hour, in which case, the watermaker production must be doubled to make same volume in half the time and thus save diesel/wear.
From the DIY point of view, the 2 most expensive items are the membranes and pump. Im still unclear about the pump choice. Obviously a high pressure one with enough capacity to provide adequate GPH to make product and flush, but it has to be a piston type as no other will provide the 800 psi needed.
SS or bronze? It seems there is a split in opinion. Bronze is a cheaper, more commonly available type found in commercial
machines, whilst SS is a bit more specialist and therefore more expensive. Am i correct in assuming the pump is like an engine with 3 cylinders in a block?
In which case, the block material is irrelevant, so SS liners can be installed with SS pistons?
Am i over complicating things?
valves, pressure guages,fittings, hoses, prefilters, (dairy industry is a good source for housings and filters) etc are all readily available.
That only leaves the membrane. Not something which can be home made and has to be bought in.
It seems like there is more of a supply industry set up in the US for membranes. What are the options. Can they be bought direct from manufacturer or does it have to be through an agent? The pressure vessel (tube) has to be matched to the specific membrane i guess?
I dont normaly drink coffee but now seems like a good time.