ARMY TM 10-4610-309-14
MARINE CORPS TM 10802A-14/1
TACTICAL WATER PURIFICATION SYSTEM (TWPS)
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DESCRIPTION AND THEORY OF OPERATION
THEORY OF OPERATION
Main Pressure Control Valve HCV-401 and Auxiliary Pressure Control Valve HCV-401A are used to
bypass some of the reject flow around the turbocharger and directly to waste (see Figure 13). This
enables the operator to reduce the flow of reject through the turbocharger and, in turn, reduce the
pressure boost that the turbine delivers to the RO feed.
RO Reject Pressure Gauge PI-401 indicates the reject pressure leaving the RO vessels.
Reject Check Valve V-411 prevents back flow into the RO elements when cleaning the MF.
Reject Flow Element FE-401 measures the reject flow. RO Reject Flow Transmitter FT-401 (see Figure
5) receives the flow element output and sends flow information for display on the Operator Control Panel
(OCP).
REJECT FLOW ELEMENT
TURBOCHARGER BYPASS
FE-401
TURBOCHARGER
REJECT
CHECK VALVE
V-411
TO
WASTE OUT
MAIN PRESSURE
CONTROL VALVE
WASTE OUT
HCV-401
REJECT OUT
AUXILIARY PRESSURE
CONTROL VALVE HCV-401A
RO REJECT PRESSURE GAUGE PI-401
Figure 13. RO System: RO Vessels to Waste Out.
At both ends of each RO vessel, three-way valves direct product flow from each element to the product
manifold or to the sample/drain hose for flow rate and conductivity measurement or for draining (see
Figure 14). A Low Range Conductivity Element, CE-501A, and a High Range Conductivity Element, CE-
501B, measure the product water conductivity. These are connected to the Conductivity Analyzer CIT-
501, which is mounted in the instrument/solenoid panel (see Figure 5). The conductivity analyzer
provides an output to the PLC which displays the measurement as mg/l total dissolve solids TDS on the
OCP. This indicates how much salt is in the product water. A high alarm indicates when the TDS is
greater than 1000mg/L or when the calculated % Salt Rejection is too low.
Product Pressure Gauge PI-501 reads the product pressure. Product Relief Valve RV-501 is set to
relieve if pressure exceed 20 psig.
Product Vacuum Breaker VB-501 eliminates siphoning, which could pull chlorinated product water back
into the RO when not in operation.
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