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The suction and discharge pipe/hose material should be compatible with the liquid being
pumped.
CAUTION!!!
If hose is used on the suction line it should be of the reinforced type to prevent collapse under
suction lift.
DANGER!!!
If a manual shut-off valve is installed in the discharge line, it must not be left closed during
operation, a closed manual shut off valve will cause overheating and possible explosive rupture
of the pump casing. Personnel could be severely injured!
DISCHARGE PIPING
Use a concentric taper on the discharge side to increase discharge pipe diameters. All valving
and additional fittings should be the same size as the discharge main-line. The discharge size
should be adequate to maintain reasonable velocities and reduce friction losses. It is strongly
recommended that a pressure relief valve is installed on the discharge piping.
SUCTION & DISCHARGE PIPE FLANGES
All piping is to be supported, braced and lined up square before connection to the pump
flanges. A flexible fitting is recommended on both suction and discharge, to eliminate
misalignment loads or stresses being transmitted to the pump.
NOTE: Flexible pipe couplings must be restrained so as not to transmit any strain to the pump
flanges when expanding or contracting under pressure. Unrestrained expansion fittings can
transmit enormous forces to the pump flanges.
SCREENING
Make provisions for the installation of a suction screen or strainer to prevent any debris from
clogging the impeller. The open area of the strainer should be equal to at least four (4) times
the area of the pipe. The screen should be rigid enough to prevent collapse when flow is
reduced due to clogging.
SUMP DESIGN
The submergence of the suction pipe into the liquid should be at least four (4) to five (5) times
the pipe diameter. If this is not possible then provide a baffle or a floating board. This is to
prevent any vortex action allowing air into the pipe. For best performance a bell mouth fitting
is recommended. Recommended pipe submergences for various flows as well as recommended
bell diameters are shown in the table below whose data was taken from ANSI/HI 9.8-1998.
FLOW (GPM)
SUBMERGENCE WITH BELL (FT)
Bell Diameter (in)
Submergence (FT)
500
1000
1500
2000
6.1
8.6
10.6
12.2
2.1
2.6
3.0
3.3
2500
3000
3500
4000
13.6
14.9
16.1
17.2
3.5
3.7
3.9
4.1
4500
18.3
4.3
7
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