13-3.3 High Pressure (HP) pump skid. The HP pump skid consists of a steel skid frame with a diesel engine, an HP
pump, and a multiple V-belt drive mounted on it. The diesel engine drives the HP pump through the V-bell drive system.
The HP pump, in turn, boosts feedwater pressure from the pretreatment skid to the higher pressure required for the
reverse osmosis process in the RO block assembly. The skid carries all engine accessory equipment such as batteries,
exhaust system, and alternator. Diesel engine controls are mounted on top of the V-belt housing.
13-3.4 Reverse Osmosis (RO) block assembly. The RO block assembly is a steel skid and frame that supports 16
pressure tube assemblies and their associated manifolds and piping. The pressure tubes each hold five RO membrane
elements. Sample valves are located at the end of each pressure tube for monitoring water quality. A product water
sample valve is also located in the piping leading to the drinking water tanks. A flowmeter measures product water flow.
A throttling valve in the brine discharge piping provides a means of controlling product water flow and is adjusted in
conjunction with the HP pump output pressure. The HP pump output is adjusted by varying diesel engine speed to
increase or decrease seawater pressure flowing to the RO block.
13-4 System Capabilities
24-hr production per ROWPU
24-hr production (total)
The above figures are for a production cycle of 10 hours of operating time followed by 2
hours of nonoperating time to accomplish backflushing, cartridge changing, and other
13-5 Limitations. Seawater (feedwater) must be free of chlorine, detergents, and other contaminants. In addition, the
ROWPU cannot be operated in sea conditions that exceed Sea State 3.
13-6. Performance characteristics
Seawater flow rate from seawater pump
Product water flow rate from RO block
Brine flow rate from RO block
440 Vac, 3 ph, 60 Hz