Increase stroke setting in increments of 5, wait tenminutes and record new turbidity reading.
Continue to increase stroke setting by 5, waiting tenminutes and then recording new turbidity reading.
As the stroke is increased, the turbidity should decrease and then level out at the optimum
Never run at less than initial setting as determined by water type, see Table 2-17.
The optimum setting can be determined by any one of the following situations: (see Table 2-24)
Situation 1 - If the turbidity decreases with increased stroke setting, but then stops changing for 3 successive stroke
increases, set the stroke at 5 less than the last setting. If the turbidity increases after a stroke change, set the stroke
back to the setting which first resulted in the lowest turbidity.
Situation 2 - If the speed is at a setting of 16 or 32.5 and the stroke reaches 100 with the turbidity still decreasing with
each stroke increase, set the stroke back to 50 and double the speed. Continue optimization by increasing stroke
Situation 3 - If the speed is at 65 and the stroke reaches 100 with the turbidity still decreasing with each stroke
increase, leave the stroke at 100 for the final setting.
Situation 4 - If increased stroke settings from the initial setting do not result in decreasing turbidity and the speed is
32.5 or 65, decrease the speed by 1/2 and repeat.
Situation 5 - If increased stroke settings from the initial setting do not result in decreasing turbidity and the speed is
16, set the stroke at 10 for the final setting.
If not enough or too much polyelectrolyte is pumped to the system, the formation of floc
particles will not be controlled; a mid-range concentration (optimization) of polyelectrolyte
is required for operation.
Enter Data Log information for start-up (see Appendix H).
One yellow light will cancel out all other alarms.
Once polylectrolyte in feed water and chlorine level in product water are correctly set the ROWPU is fully operational. It will
keep on working with very little attention. Only routine tasks, and special jobs indicated by warning lights and the alarm horn,
will need to be done.
During a typical filter run (i.e. time between backwashes) the turbidity will usually continue
to decrease with time. On occasion it will increase after some time, indicating that the filter
is so loaded with dirt that it can no longer remove dirt efficiently and it requires
If allowed by mission demands, backwash media filter after optimization (para. 2-21).
Pressure switch operational set points. Operate the ROWPU and proceed as follows:
Perform operational set points/pressure switch test at first start up and weekly.
Slowly close the product block valve while watching the product water pressure gage. The ROWPU should shutdown at
35-45 psig. Another method is to open product utility hose and close product shut-off valve to shut down ROWPU.
Perform this test weekly using product utility hose.
2-86 Change 12