Gorman-Rupp Pumps 11 1/2A3-E2 1P 1045642 and up - Manual (Page 16)

OM-04091 10 SERIES
OPERATION PAGE C - 2
Consult the operating manual furnished with the
pump motor before attempting to start the motor.
If rotation is incorrect on a three‐phase motor, have
a qualified electrician interchange any two of the
three phase wires to change direction. If rotation is
incorrect on a single‐phase motor, consult the lit­
erature supplied with the motor for specific instruc­
tions.
OPERATION
Lines With a Bypass
Close the discharge throttling valve (if so
equipped) so that the pump will not have to prime
against the weight of the liquid in the discharge
line. Air from the suction line will be discharged
through the bypass line back to the wet well during
the priming cycle. When the pump is fully primed
and liquid is flowing steadily from the bypass line,
open the discharge throttling valve. Liquid will then
continue to circulate through the bypass line while
the pump is in operation.
Lines Without a Bypass
Open all valves in the discharge line and start the
motor. Priming is indicated by a positive reading on
the discharge pressure gauge or by a quieter op­
eration. The pump may not prime immediately be­
cause the suction line must first fill with liquid. If the
pump fails to prime within five minutes, stop it and
check the suction line for leaks.
After the pump has been primed, partially close the
discharge line throttling valve in order to fill the line
slowly and guard against excessive shock pres­
sure which could damage pipe ends, gaskets,
sprinkler heads, and any other fixtures connected
to the line. When the discharge line is completely
filled, adjust the throttling valve to the required flow
rate.
Leakage
No leakage should be visible at pump mating sur­
faces, or at pump connections or fittings. Keep all
line connections and fittings tight to maintain maxi­
mum pump efficiency.
Liquid Temperature And Overheating
The maximum liquid temperature for this pump is
160
_ F (71_C). Do not apply it at a higher operating
temperature.
Overheating can occur if operated with the valves
in the suction or discharge lines closed. Operating
against closed valves could bring the liquid to a
boil, build pressure, and cause the pump to rup­
ture or explode. If overheating occurs, stop the
pump and allow it to completely cool before servic­
ing it. Refill the pump casing with cool liquid.
Do not remove plates, covers, gauges,
pipe plugs, or fittings from an over­
heated pump. Vapor pressure within the
pump can cause parts being disen­
gaged to be ejected with great force. Al­
low the pump to completely cool before
servicing.
Strainer Check
If a suction strainer has been shipped with the
pump or installed by the user, check the strainer
regularly, and clean it as necessary. The strainer
should also be checked if pump flow rate begins to
drop. If a vacuum suction gauge has been in­
stalled, monitor and record the readings regularly
to detect strainer blockage.
Never introduce air or steam pressure into the
pump casing or piping to remove a blockage. This
could result in personal injury or damage to the
equipment. If backflushing is absolutely neces­
sary, liquid pressure must be limited to 50% of the
maximum permissible operating pressure shown
on the pump performance curve (see Section E,
Page 1).
Pump Vacuum Check
With the pump inoperative, install a vacuum gauge
in the system, using pipe dope on the threads.
Block the suction line and start the pump. At oper­
ating speed the pump should pull a vacuum of 20
inches (508,0 mm) or more of mercury. If it does
not, check for air leaks in the seal, gasket, or dis­
charge valve.