GORMAN-RUPP OM--04760 User Manual

Page 17

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PAGE C -- 2

companying decals. Reverse rotation

could loosen the impeller and seriously

damage the pump.

If the pump is driven by an electric motor, consult
the operating manual furnished with the motor be-
fore 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-


Pump speed and operating points must be

within the continuous performance range

shown on the pump curve. (See the Parts

List Manual accompanying the pump.)

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
power source. Priming is indicated by a positive
reading on the discharge pressure gauge or by a
quieter operation. The pump may not prime imme-
diately because 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

Do not operate the pump against a

closed discharge throttling valve for

long periods of time. If operated against

a closed discharge throttling valve,

pump components will deteriorate, and

the liquid could come to a boil, build

pressure, and cause the pump casing to

rupture or explode.


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

Refer to the Specification Data sheet for the


mum liquid temperature for your specific pump.
Do not apply the pump at a higher operating tem-

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 cool before servicing it. Refill
the pump casing with cool liquid.

Allow an over-heated pump to com-

pletely cool before servicing


Do not re-

move plates, covers, gauges, or fittings

from an over-heated pump. Liquid with-

in the pump can reach boiling tempera-

tures, and vapor pressure within the

pump can cause parts being disen-

gaged to be ejected with great force. Af-