Figure 1. SWRO plant schematic
VALVE SELECTION
It’s important to note that valves used in
the SWRO process are applied to low-
pressure and high-pressure services,
which affect both valve configurations
and the materials of construction. The
ultimate goals are to maximize process
efficiency, minimize maintenance and
downtime, and contain or reduce energy
expenses. Proper selection can improve
the chances of extending the life of
valves and increasing system uptime,
while improving energy efficiency.
Intake
The goal of the intake process is to
remove materials that could foul or
damage the efficiency of the expensive,
sensitive membranes. In the intake
process, raw seawater, with its high con-
tent of dissolved chlorides, enters the
plant and all solids, such as silt, sand
and organic materials, are removed.
This is accomplished through standard
sand and cartridge filters and, more
recently, by ultra-filtration techniques—
along with chemical pretreatment. For
the process, water intake valves are typ-
ically specified with rubber-lined cast
