TM 10-4610-240-10
TM 08580C-10/1
T.O. 40W4-13-21
FIGURE 2-71. BACKWASH WATER TANK
(2) After backwashing, adjust brine water level in tank to 7 inches. You may have to drain water from tank or
operate ROWPU normally until you obtain 7 inches.
(3) Check for 7-inch brine water level with telescoping aluminum mixing paddle. Paddle has a 7-inch mark for
checking the brine depth.
(4) Begin by adding one pound of citric acid to water in backwash water tank and mix with aluminum paddle
until all granules are dissolved. (More citric acid may be added later to bring pH of brine near but not
below 3 5
NOTE
If in past, when using same source water, brine has been very alkaline, then more citric acid may be added to start;
however, never let pH of brine drop below 3.5 or damage to the R.O. elements will occur.
(5) Remove backwash hose from outlet of the backwash pump and connect VENT VESSELS hose to outlet o
f
backwash pump.
(6) Make sure REGULATE PRODUCT FLOW valve is open (counterclockwise).
(7) Open VENT VESSELS valve. This valve should remain open at all times except when producing purified
water.
(8) Check to see that the valve on the bottom of backwash water tank is fully open (turned fully to the left
(counterclockwise) until it stops).
(9) Remove product water hose (14, figure 2-27) from product water tank and allow hose from ROWPU to
drain on the ground. Leave brine water hose in backwash water tank.
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