CHAPTER
12
Manual No. 016-0159-925 Rev. F
77
Chapter 12
Flow Meter
Maintenance &
Adjustment Procedure
Note:
Thoroughly bleed nurse tank hose and all other system lines prior to disassembling the flow meter,
fittings, or hoses.
1.
Remove flow meter from the vehicle and flush with clean water to remove any chemicals.
2.
Remove flange bolts or clamp from the flow meter.
3.
Remove the turbine hub and turbine from inside flow meter.
4.
Clean turbine and turbine hub of metal filings or any other foreign material, such as wettable powders.
Confirm that the turbine blades are not worn. While holding the turbine hub in your hand, spin turbine. The
turbine should spin freely with very little drag inside the hub.
5.
If transducer assembly is replaced or if turbine stud is adjusted or replaced, verify the turbine fit before
reassembling. Hold turbine hub with turbine on transducer. Spin turbine by blowing on it. Tighten turbine
stud until turbine stalls. Loosen turbine stud 1/3 turn. The turbine should spin freely.
6.
Re-assemble flow meter.
7.
Using a low pressure (5 psi) [34.5 kPa] jet of air, verify the turbine spins freely. If there is drag, loosen hex
stud on the bottom of turbine hub 1/16 turn until the turbine spins freely.
8.
If the turbine spins freely and cables have been checked per
page 70, but flow meter still is not metering properly, replace flow meter transducer.
Procedure to Recalibrate Flow Meter:
1.
Press METER CAL and enter a value of 10 [38].
2.
Press TOTAL VOLUME and enter a value of 0.
3.
Place the master switch and all boom sections in the OFF position.
4.
Remove a boom hose and place it into a calibrated 5 gallon [19 liter] container.
5.
Toggle the master switch and the boom switch corresponding to the hose that was placed in the container.
Pump exactly 10 gallons or 38 liters.
6.
Press TOTAL VOLUME. The reading displayed is the new meter cal value. This value should be within
+/- 3% of the calibration number stamped on the tag of the flow meter.
7.
Repeat this procedure several times to confirm accuracy (Always “zero out” the total volume display before
retesting).
Note:
For greatest precision, set meter cal to 100 [378] and pump 100 gallons (378 liters) of water.
8.
To verify the flow meter calibration, the fill applicator tank with a predetermined amount of measured liquid
(i.e. 250 gallons).
Note:
Do not rely on graduation marks molded into the applicator tank.
