Fig. No.
21
Subject to flow meter manufacturer’s recommendations.
16
of
46
Subject to change without prior notice
INSTALLATION OPERATION AND MAINTENANCE INSTRUCTIONS
FIRE PUMPS - NF-VTP SERIES
Ref. No. NFVTP-IOM/
2016
/V.
02
5.11. Operating instructions of flow meter
The flow meter arrangement of NAFFCO pump set is built as per flow meter manufacturer’s instructions. The
operating guidelines are following (See Fig. No.
21
also):
1
.
Close the system OS&Y valve.
2
.
Open OS&Y test line valves (shown in the Fig. No.
21
) or butterfly throttle valve (according to- system
requirement).
3
.
Purge meter located on venture as follows:
-
Open shut off valves and air vent valves.
-
When a steady stream of water is passing through each plastic hose, the meter is purged of
air.
-
Close air vent valve after purging.
4
.
Open the air release valve provided upstream of the flow meter.
5
.
Start fire pump, read meter in gpm.
6
.
Refer to pump flow requirement and adjust throttle valve.
7
.
After test, open system valve and close system test line and throttle valves.
5.12. Pressure sensing line
»
For all pump installations, including jockey pumps, each controller shall have its own individual pressure sensing
line.
»
The pressure-sensing line connection for each pump is made between that pump’s discharge non- return valve and
discharge control valve.
»
This line has
½
” non return valve with
2
.
4
mm hole in the clapper and will be connect in opposite direction.
»
The end of pressure sensing line is connected with ball valve to drain the water.
»
The pressure sensing line is intended to control automatic starting of the pump motor and the running cycle of
the fire pump.
»
The pressure sensing line shall be brass, rigid copper pipe or stainless steel pipe or tube, and the fittings shall be
of
½
in. (
15
mm) nominal size.
»
The use of soft copper tubing is not permitted for pressure sensing line because it is easily damaged.
