3-26. RAW WATER FLOWMETER.
a. General. The RAW WATER FLOWMETER shows the rate which raw water IS entering the ROWPU. This
paragraph describes test and inspection of the RAW WATER FLOWMETER.
b. Removal. If necessary, remove raw water flowmeter assembly in accordance with paragraph 2-69.
Be sure to attach water source to inlet port of meter, which is
marked IN. Running water backwards, into the outlet port, can
Pipe leading to meter inlet (IN) for test must be straight for at
least 20 inches (50 cm) before entering meter. Otherwise, test
will not be accurate.
(1) Attach inlet port of meter to a straight pipe at least 20 inches (50 cm) long, leading to a metered water
source. The source must have an output range of 5 to 40 gpm (19 to 151 Ipm).
If no metered source is available, run the source into a
graduated tank for 1 minute to determine exact flow rate.
(2) Run water through meter at rate of 5 gpm (19 Ipm). If meter reading varies from flow rate by more than
0.15 gpm (0.6 Ipm), discard meter.
(3) Run water through meter at rate of 20 gpm (76 Ipm). If meter reading varies from flow rate by more
than 0.60 gpm (2.3 Ipm), discard meter.
(4) Run water through meter at rate of 35 gpm (132 Ipm). If meter reading varies from flow rate by more
than 1 gpm (3.8 Ipm), discard meter.
(1) Inspect dial crystal for cracks or scratches.
(2) Inspect dial face for legibility. Make sure needle can move freely.
(3) During test, check meter body and dial for leaks.