Pump Solutions Group Neptune Polymaster Liquid Polymer Blend & Feed System - Manual (Page 16)

11
CALIBRATION
1. Calibration of the polymer pump is recommended once the system is operational. Differences in
the specific gravity and viscosity of polymers, as well as the specific piping arrangement used, require
calibration of the pump to determine the precise polymer feed rate at a particular pump setting. A chart is
developed to show the flow rates at various pump settings specific to the polymer and the installation site.
The dilution water flowmeter requires no calibration.
2. Connect a calibration cylinder with isolation valves to the polymer inlet line. Neptune offers
complete calibration kits.
3. Fill the cylinder with polymer using gravity feed for a flooded suction installation or by pouring the cylinder
full of polymer if using an arrangement where the polymer is pulled up out of a drum. Never place water
in the calibration cylinder as this could cause gelling and solidifying of polymer in the suction line or
pump head. The cylinder should be isolated from the polymer input line so only polymer from the cylinder
is drawn. Measure the amount of polymer drawn out of the cylinder in a 1-2 minute test.
4. With the system on and dilution water flowing at a rate which ensures the proper polymer percentage
make-down. Set the pump to Length to 100%, and the stroke speed to 25%. Open the polymer cylinder,
time the flow being pumped for 1 or more minutes, close the valve, and record the volume. Never run the
polymer metering pump without a supply of chemical. Do not starve the pump. When switching from the
normal suction line to the calibration cylinder, open the cylinder valve first and close the suction line valve
last. When restoring normal flow, open the suction line first and close the calibration cylinder valve last.
5. Repeat Step 4 for pump settings at 50%, 75% and 100%.
6. With the data recorded, plot the pump setting versus the amount of polymer drawn down in the calibration
cylinder as measured in milliliters. Convert the data into flow rates using one of the formulas below. Plot
the flow rate vs. pump setting on the calibration graph on the next page.
Flow (gph) = V (ml) x 3600
3785 x T (sec)
Flow (gph) = V (ml) x 60
3785 x T (min)
gph - gallons per hour
V - volume in milliliters
T - time in seconds or minutes
7. Note: Since stroke and speed may both be adjustable, it is recommended to select a stroke length convenient
for the application and to develop the calibration graph based on changes in the stroke speed. Additional
calibration graphs may then be developed for other stroke length settings repeating 25%, 50%, 75% and
100% of stroke speed for each stroke length tested.