Water, water everywhere and not a drop to drink. The idea of being at sea began when I was very young and enraptured with stories in a survival book, frequently of downed airmen adrift in the ocean.
Water enters the sea chest and is strained. It then passes through a ball valve, two pre-filters, one 20 and the next 5 microns to remove particles, the to the saltwater pump, or boost pump. The boost pump draws the water through the prefilters and ensures there is some positive pressure for the seawater entering the high pressure pump. The high pressure pump is just below the waterline but not enough to the necessary pressure and flow required to feed the high-pressure pump.
Boost Pump Options:
Blueline 70 HD Pump 29 gpm, max head 39 ft $420
Little Giant 5MD-SC 16 gpm @ 3ft, 15 @ 10 ft. $332
Pan World 200PS Pump 29 gpm, max head 39 $260
Industrial Pressure Gauge Stainless Steel, Liquid-Fillable, 15 psi $90
Pressure Switch - If we add a boost pump it would supply saltwater for research projects, wash down, and plumbing so it would be convenient to have an automatic pressure switch.
Pre-filters for Watermaker water only, not the wash down supply path.
Harmsco Polyester-Plus 20" × 2¾", 20 Micron Pleated Sediment Cartridge (12 GPM, 12 sq ft Media) $21
Harmsco Polyester-Plus 20" × 2¾", 5 Micron Pleated Sediment Cartridge (12 GPM, 12 sq ft Media) $21
Pentek 150560, 3G 20" Clear Filter Housing $65 x 2 = $130
High Pressure Pump Motor
North American (F56C1S4C) Electric Motor - 1HP 1800RPM 56CFR 1PH TEFC $250
High Pressure Pump:
Cat Pump 247 Plunger Pump, 3.6 gpm, 1/2" FNPT Inlet x 3/8" FNPT Outlet, 1200 psi $1485
RO Membrane:
4 -Filmtec SW30-2521 Sea Water 300 GPD RO Membrane Element $195 x 4 $780
Membrane Housing:
4 - 3" 316 Stainless Steel Sch 40, 84 inches x 2 $700 and 4 - 3"316 Stainless Steel sch 40 end caps and plugs $250 Total aprox $1000
HCTI Seawater Vessels PV-2521-SW $305 each $1220