Gorman-Rupp Pumps RD2A31-BAR All serial numbers - Manual (Page 18)

RS AND RD SERIES PUMPS OM-03989
PAGE C - 4 OPERATION
The product recirculates through the return tube
assembly “C” to the pump suction flange. The liq­
uid pressure equalizes the priming pump spring
pressure and the priming pump slides into neutral.
At this point the pump is fully primed.
In neutral position the priming pump circulates a
small amount of liquid through the discharge tube
to the float chamber through the return tube and
back into the suction flange.
If air or vapor enters the suction piping during the
pumping operation, again the discharge line
check valve will close, and the priming pump will
again evacuate the air through the Air Release
Valve.
STARTING
Consult the operations manual furnished with the
power source.
Before connecting a motor to the incoming power,
check that the electrical service available matches
the pump motor requirements stamped on the mo­
tor nameplate. Check that the motor speed meets
pump specifications. The pump is designed to be
driven at a maximum full load speed of either 1750
RPM (RS Series) or 3450 RPM (RD Series).
Rotation
The correct direction of pump rotation is indicated
by an arrow on the pump body or accompanying
decals. The pump could be damaged and per­
formance adversely affected by incorrect rotation.
If pump performance is not within the specified lim­
its (see the curve in the Parts List Manual on page
1), check the direction of rotation before further
troubleshooting.
Consult the operating manual furnished with the
power source before attempting to start the power
source.
If an electric motor is used to drive the pump, re­
move V‐belts, couplings, or otherwise disconnect
the pump from the motor before checking motor
rotation. Operate the motor independently while
observing the direction of the motor shaft, or cool­
ing fan.
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
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 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
ter the pump cools, drain the liquid from
the pump by removing the casing drain
plug. Use caution when removing the
plug to prevent injury to personnel from
hot liquid.