Gorman-Rupp Pumps 81 1/2P47A-B 801848 and up - Manual (Page 10)

80 SERIES OM-02163
PAGE B - 3 INSTALLATION
mum use of elbows and fittings, which substan­
tially increase friction loss. If elbows are necessary,
use the long‐radius type to minimize friction loss.
Flexible connectors are required on suction and
discharge connections in order to prevent piping
loads.
The suction and discharge lines must be
supported and connected to the pump
with flexible connectors in order to prevent
piping loads. The pump warranty will be
voided if flexible connectors are not
used.
Connections to Pump
Before tightening a connecting flange, align it ex­
actly with the pump port. Never pull a pipe line into
place by tightening the flange bolts and/or cou­
plings.
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
lines are used, they should have adequate support
to secure them when filled with liquid and under
pressure.
Gauges
Most pumps are drilled and tapped for installing
discharge pressure and vacuum suction gauges.
If these gauges are desired for pumps that are not
tapped, drill and tap the suction and discharge
lines not less than 18 inches (457,2 mm) from the
suction and discharge ports and install the lines.
Installation closer to the pump may result in erratic
readings.
SUCTION LINES
To avoid air pockets which could affect pump prim­
ing, the suction line must be as short and direct as
possible. When operation involves a suction lift, 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.
The suction line should not exceed 20 feet (6 me­
ters) in length.
Fittings
The use of plastic fittings to connect suction and
discharge lines to the pump is recommended. Use
a good grade of pipe sealant on the threads of the
fittings. Draw the fittings up hand tight, then give
them one full turn with a wrench.
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 with the flat part of the 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
to use it; any spherical solids which pass through a
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 will not permit passage
of solids larger than the solids handling capability
of the pump.
This pump is designed to handle up to 9/16 inch
(14,3 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