backwash pump. Product water is sent to the backwash water tank during this
procedure to keep the citric acid solution from becoming concentrated. The backwash
pump strainer fiIters brine before it enters the multimedia fiIter or reverse osmosis
elements. Indicating the rate of brine flow into the multimedia fiIter during backwash is
the backwash water flow gage. The check valve prevents raw water from entering the
backwash water Iine. During ROWPU startup, the vent vessels valve bypasses the
reverse osmosis elements untiI the multimedia fiIter stabiIizes. During element
cleaning, the vent vessels valve passes brine/citric acid solution from the backwash
pump to the reverse osmosis elements.
(5) Potable/drinking storage. The produce water sample ball valves provide
samples of fiItered water at input ends of the pressure vessels. The product water
sample elliptic valves, in the normal position, pass the product water out of the reverse
osmosis elements to the product water tanks. In the sample position, the valves direct
the product water out of each reverse osmosis vessel as a sample. Design prevents
shutdown of the water flow whiIe switching between the normal and the sample
position. The chemical feed metering pump chlorine drive unit adds chlorine to the
product water to prevent bacteria growth. ControlIing the rate of product water flow to
the product water tanks is the regulate product flow valve. The check valve prevents
back flow in the product Iine. The product water flow gage indicates the rate of product
water flow to the product water tanks. The water meter (totalizer type meter) indicates
the total amount of possible water produced by the ROWPU. There is an in-Iine TDS
monitor that indicates the quality of the product water, calibrated in total dissolved solids
(TDS). Two product water tanks store the product/potable water. A valve controls the
flow of produce water from the first product water tank to the other.
(6) Water distribution. The distribution pump develops pressure to move the
product water from the product water tanks through the distribution nozzle. This nozzle
controls the rate of flow of the product water from the product water tanks to the user.
Chemical and radiological fiIters overpack items used to remove chemical or
tubing needed to connect one or the other fiIters in Iine between the two product water
tanks. This is only installed when needed. Operating Iife is 100 hours for either type of
filter.
d. Miscellaneous.
(1) Chemical supplies. The operator should have ample quantities of
chemical supplies on hand for his immediate operational requirements and evidence of
additional quantities "due in" for future needs. Chemicals should be stored in a cool, dry
place away from any fire hazard and segregated to preclude accidental mixing.
(2) Records and publications. In addition to the pertinent TM for the type of
equipment in use, the operator should maintain the following records:
MD0160
5-36