b. Compare the TDS readings for the top two vessels. If the difference
between the two is more than the maximum difference allowed in Table 1-7,
the vessel with the higher TDS has internal O-ring leakage.
procedure for the bottom vessels. Troubleshoot the vessels that indicate O-
The alert horn will
sound and the ROWPU will automatically shutdown.
Push the alarm silence
button and troubleshoot the problem.
The following reasons will cause an
c. Excessive product water pressure from the vessels.
d. Low water level in the clean/flush tank.
PART C - SHUTDOWN AND DISMANTLING OF THE 3,000-GPH ROWPU
The procedures to use for equipment shutdown will depend on how long
your operation will be shut down.
Once your tanks are full you can shut
down the ROWPU. You will need to anticipate how long you will be shutdown.
Determine when you will have to start the unit up again. You can determine
when you will have to fill your tanks up by reviewing the distribution
schedule for your water point.
You will have to determine shutdown times
for scheduled and unscheduled maintenance.
"Routine shutdown to stand-by" procedures are used when the ROWPU is
to be shutdown for three hours or less. If the ROWPU is kept in the "stand-
by" status for more than three hours, the RO elements may lose performance
and require cleaning earlier than scheduled.
If the "routine shutdown to
stand-by" procedures are to be used have your crew perform the following:
b. After the feed flow drops below 60 GPM, stop the booster pump, the
chemical pumps, and the raw pump.
c. Allow the media filter pressure to drop to less than 5 psi before