Gorman-Rupp Pumps 81 1/4A3-X.50 3P 794462 and up - Manual (Page 14)

80 SERIES OM−00783
OPERATION PAGE C − 2
OPERATION
Lines With a Bypass
Since this pump does not have a suction check
valve, the discharge end of the bypass line must be
submerged in order to maintain suction.
Close the throttling valve in the discharge line and
open the shut-off valve in the bypass line so that
the pump will not have to prime against the weight
of the liquid in the discharge line. Start the motor.
When the pump has primed and liquid is flowing
steadily through the bypass line, close the bypass
shut-off valve and open the discharge throttling
valve.
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
rate.
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.
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 operat-
ing 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 completely cools, drain the
liquid from the pump by removing the
casing drain plug. Use caution when re-
moving the plug to prevent injury to per-
sonnel from hot liquid.
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