Gorman-Rupp Pumps 06C1-GHH 1071445 and up - Manual (Page 22)

OM-03179 0 SERIES
OPERATION PAGE C - 4
Open the suction line, and read the vacuum gauge
with the pump primed and at operation speed.
Shut off the pump. The vacuum gauge reading will
immediately drop proportionate to static suction
lift, and should then stabilize. If the vacuum reading
falls off rapidly after stabilization, an air leak exists.
Before checking for the source of the leak, check
the point of installation of the vacuum gauge.
NOTE
Petroleum products are very sensitive to changes
in temperature. Warmer temperatures elevate the
product vapor pressure resulting in low vacuum
readings. Do not mistake temperature problems for
faulty pump installation or performance.
STOPPING
Never halt the flow of liquid suddenly. If the liquid
being pumped is stopped abruptly, damaging
shock waves can be transmitted to the pump and
piping system. Close all connecting valves slowly.
On engine driven pumps, reduce the throttle
speed slowly and allow the engine to idle briefly be­
fore stopping.
If the application involves a high discharge
head, gradually close the discharge
throttling valve before stopping the pump.
After stopping the pump, take precautions to en­
sure that the pump will remain inoperative.
Cold Weather Preservation
Normal freezing conditions will not damage the
pump. However, during extremely severe condi­
tions care should be exercised during start‐up, es­
pecially if the pump has been idle for more than a
few hours.
GEARBOX TEMPERATURE CHECK
The gearbox runs at higher than ambient tempera­
tures because of heat generated by friction and
churning of the lubricating oil. Temperatures of ap­
proximately 250
_
F (121
_
C) are considered normal.
During continuous operation, the oil temperature
can exceed 300
_
F (149
_
C).
NOTE
For continuous duty operation (when the pumping
period exceeds 30 minutes without a 20 minute
minimum cool‐down period between pumping
cycles), see Continuous Duty Pumping in MAIN­
TENANCE AND REPAIR, Section E for lubrication
instructions.
Checking gearbox temperatures by hand is inac­
curate. Place a contact‐type thermometer against
the housing and record this temperature for future
reference. The temperature of the lubricating oil
will be approximately 10
_
F (6
_
C) higher than the
housing surface temperature.
Gearbox components may be damaged
by excessive heat. Limit continuous opera­
tion to 30 minutes or less to prevent heat
build‐up. See Continuous Duty Pumping
in MAINTENANCE AND REPAIR, Section
E for specific lubrication instructions if the
pump is operated on a longer duty cycle.
A sudden increase in gearbox temperature is a
warning that the bearings are at the point of failing.
Make certain that the bearing lubricant is of the
proper viscosity and at the correct level (see LU­
BRICATION in Section E). Bearing overheating
can also be caused by shaft misalignment and/or
excessive vibration.
When pumps are first started, the bearings may
seem to run at temperatures above normal. Con­
tinued operation should bring the temperatures
down to normal levels within 20 minutes or less.