Section Ill. MAINTENANCE PROCEDURES
INTRODUCTION. This section provides maintenance procedures to be performed by the operator.
CHANGING R.O. ELEMENTS.
a. General. The R.O. elements are replaced anytime TDS of product water exceeds 1500 parts per
million and cannot be corrected by using procedures described in item 17, Table 3-2, Troubleshooting. Each
R.O. vessel contains two R.O. elements.
If removing end caps from more than one R.O. vessel, mark end caps with
pencil or chalk to ensure they are replaced on correct vessel and correct side.
Shutdown ROWPU and relieve all pressure before removing the R.O. element,
or loosening any parts of the R.O. pressure vessels.
Some steps require two people.
b. Pre-removal Procedures.
(1) Shut the ROWPU down normally (para. 2-31).
(2) Open all R.O. vents, drains, and valves (fig. 2-36 and 2-37).
(3) Remove strainer and hose from water source.
To reduce chances of leaks, mark end caps and vessel (alignment marks) with
chalk or pencil so that end caps are installed in the same position.
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