OM--01936TSERIES
PAGE B -- 3INSTALLATION
Lines near the pump must be independently sup-
ported to avoid strain on the pump which could
cause excessive vibration, decreased bearing life,
and increased shaft and seal wear. If hose-type
linesareused,theyshouldhaveadequatesupport
to secure them when filled with liquid and under
pressure.
Gauges
Most pumps are drilled and tapped for installing
dischargepressureandvacuumsuctiongauges.If
these gauges are desired for pumps that are not
tapped, drill and tap the suction and discharge
lines not less than 18 inches (457 mm) from the
suction and discharge ports and install the lines.
Installation closer to the pump mayresult in erratic
readings.
SUCTION LINES
Toavoidairpockets whichcouldaffectpumpprim-
ing, the suction line must be as short and direct as
possible.Whenoperationinvolvesasuctionlift,the
line must always slope upward to the pump from
the source of the liquid being pumped; if the line
slopes down to the pump at any point along the
suction run, air pockets will be created.
Fittings
Suction lines should be the same size as the pump
inlet. If reducers are used in suction lines, they
should be the eccentric type, and should be in-
stalled withthe flat part ofthe reducers uppermost
to avoid creating air pockets. Valves are not nor-
mally used in suction lines, but if a valve is used,
install it with the stem horizontal to avoid air pock-
ets.
Strainers
If a strainer is furnished with the pump, be certain
touseit;anysphericalsolidswhichpass througha
strainer furnished with the pump will also pass
through the pump itself.
If a strainer is not furnished with the pump, but is
installed by the pump user, make certain that the
total area of the openings in the strainer is at least
three or four times the cross section of the suction
line, and that the openings willnot permit passage
of solids larger than the solids handling capability
of the pump.
Thispumpisdesignedtohandleupto3-inch(76,2
mm) diameter spherical solids.
Sealing
Since even a slight leak will affect priming, head,
and capacity, especially when operating with a
high suction lift, all connections in the suction line
should be sealed with pipe dope to ensure an air-
tight seal. Follow the sealant manufacturer’s rec-
ommendations when selecting and applying the
pipe dope. The pipe dope should be compatible
with the liquid being pumped.
Suction Lines In Sumps
If a single suction line is installed in a sump, it
should be positioned away from the wall of the
sump at a distanceequalto 1-1/2 times thediame-
ter of the suction line.
If there is a liquid flow from an open pipe into the
sump, the flow should be kept away from the suc-
tion inlet because the inflow willcarry air downinto
the sump, and air entering the suction line will re-
duce pump efficiency.
If it is necessary to position inflow close to the suc-
tioninlet, installa bafflebetween theinflow and the
suction inlet at a distance 1-1/2 times the diameter
of the suction pipe. The baffle will allow entrained
air to escape from the liquid before it is drawn into
the suction inlet.
If two suction lines are installed in a single sump,
theflowpathsmayinteract, reducingtheefficiency
of one or both pumps. To avoid this, position the
suction inlets so that they are separated by a dis-
tance equal to at least 3 times the diameter of the
suction pipe.
Suction Line Positioning
The depth of submergence of the suction line is
critical to efficient pump operation. Figure 2 shows
recommended minimum submergence vs. veloc-
ity.
