GHC SERIES
OM-05845
PAGE C-2
OPERATION
manufactured to rotate in one specific di
rection. If rotation is to be changed, the
pressure relief valve must be re‐installed
with the cap pointing toward the suction
port. Additionally, if the discharge presure
is greater than the shaft seal rating (consult
your Gorman‐Rupp distributor), the pres
sure relief plugs in the back of the housing
must be switched (see
Housing Assem
bly
under
PUMP REASSEMBLY
, Section
E).
STARTING
Start the drive unit as indicated in the manufactur
er's instructions and observe the suction and dis
charge gauges. If the pump does not deliver liquid
within one minute, stop the drive unit.
Do not
oper
ate the pump more than one minute without liquid
in it; dry operation will damage or destroy the
pump.
Although this pump is self‐priming, never
operate it dry. Dry operation could cause
galling, seizing, damage to the seal or ex
cessive wear of rotating parts.
Review the previous steps outlined in
PRE‐OP
ERATION
and review
TROUBLESHOOTING
,
Section D. If everything appears normal, add liquid
to the pump housing to assist priming and start the
driver again.
If the pump does not deliver liquid, stop the pump;
it may be necessary to vent the discharge line until
liquid begins to flow.
If the pump still does not deliver after consulting
TROUBLESHOOTING
and venting the discharge
line, contact your local Gorman‐Rupp Rotary Gear
Distributor or the factory.
OPERATION
NOTE
If the pump malfunctions or does not meet operat
ing specifications, refer to
TROUBLESHOOTING
- Section D
.
A change in operating noise when liquid first enters
the pump is normal. After the pump is fully opera
tional, monitor it for any unusual noises or vibra
tion; if either occurs, shut the pump down immedi
ately.
Liquid Temperature
Do not install the pump in a service with higher liq
uid temperatures than what it was designed. Intro
ducing hot liquid into a cold pump will expand
parts unevenly, causing excessive wear, pump fail
ure, and operation may be affected. This thermal
shock can be reduced by gradually heating the liq
uid being introduced into the pump. If it is not pos
sible to heat the liquid, use heat tape and/or insula
tion to heat the pump.
High temperature bushings as well as optional
jackets which may be used to heat or cool the
pump are available options for many models.
Overheating
Overheating can occur if the pump is operated with
valves in the suction or discharge lines closed. Op
erating against closed valves could bring the liquid
to a boil, build pressure, and cause the pump to
rupture or explode. If overheating occurs, stop the
pump and allow it to completely cool before servic
ing.
Do not remove plates, covers, gauges,
pipe plugs or fittings from an overheated
pump. Vapor pressure within the pump
can cause parts being disengaged to be
ejected with great force. Allow the pump to
completely cool before cooling.
Checking Gauges
Monitor vacuum and pressure gauge readings to
ensure that the pump is operating within normal
range and delivering full flow.
Strainer Check
If a strainer has been installed in the suction line,
monitor vacuum gauge readings to detect block
age. Check the strainer if flow rate begins to drop.
