Gorman-Rupp Pumps 83B52-GX390 1324570 and up - Manual (Page 14)

OM−04738 80 SERIES
OPERATION PAGE C − 2
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
engine. Priming is indicated by a positive reading
on the discharge pressure gauge or by a quieter
operation. The pump may not prime immediately
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.
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 pumpcompletely 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.
As a safeguard against rupture or explosion due to
heat, this pump is equipped with a pressure relief
valve which will open if vapor pressure within the
pump casing reaches a critical point. If overheating
does occur, stop the pump immediately and allow
it to cool before servicing it. Approach any over-
heated pump cautiously. It is recommended that
the pressure relief valve assembly be replaced at
each overhaul, or any time the pump casing over-
heats and activates the valve. Never replace this
valve with a substitute which has not been speci-
fied or provided by the Gorman-Rupp Company.
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