INITIAL STARTING. All external surfaces of
the pump should be carefully cleaned before the pump
is started. If the factory assembly has not been dis-
turbed, it will not be necessary to dismantle the unit
for cleaning. The interior of the pump was coated with
a special rust-preventive compound after the factory
test. The removal of this compound is effected com-
pletely without any harmful results in the normal
operation of the unit.
Make sure that the shaft packing has been in-
stalled and that the gland nuts are only fingertight.
Before you start the pump, prime it by filling the
pump case and as much of the suction line as possible
with oil. If the air is not removed from the suction line,
the performance of the unit will be erratic, or it will not
pump at all. If no priming connection is provided, use
the plug on the suction connection of the pump.
Open the suction, discharge, and vent valves and
start the motor. If the pump is moving the oil satisfac-
torily, the vent valve may be closed after a few min-
utes of operation. Allow the shaft packing to leak
freely for the first 15 minutes of operation; then,
tighten the gland nuts with your fingers until there is
only a slight leakage past the packing.
If the pump fails to discharge after starting, stop
the motor, prime the pump again, and restart the
pump. If it still does not pickup oil immediately, there
may be a leak in the suction line, or the trouble may
be traced to excessive suction from an obstruction,
throttle valve, or other causes. Connecting a gage at
several points along the suction line, while the pump
is operating, helps locate the trouble. An obstruction
in the suction line causes an observable drop in pres-
sure at the point of obstruction, the lower pressure
being on the pump side.
Operating the pump without oil causes
rapid wear of the housing and bearings; there-
fore, checks for trouble must be made quickly
ROUTINE STARTING. Open the suction and
discharge valves and start the motor. Ensure that oil is
being pumped and that there is a slight leakage past
the shaft packing. Read the gages that indicate the
suction and discharge pressures for the pump, and
make sure the pump is operating normally. If it is not
pumping, follow the instructions for initial starting.
OPERATION. After the pump is in service, it
continues to operate satisfactorily with little or no
need for maintenance except normal PMS. The suc-
tion and discharge pressures should be checked at
least every 10 minutes to verify the performance of
the pump. Once each day, the shaft packing should be
inspected to see that it is properly adjusted. Any un-
usual conditions should be noted and investigated.
SECURING. Stop the motor and close the suc-
tion and discharge valves.
De Laval pumps require very little attention in
normal usage. Unless they are operated without oil or
with oil containing abrasive particles, their operation
without major overhaul is virtually unlimited.
The pump is equipped with a relief valve to pre-
vent excessive oil-pressure buildup. The relief valve
also seals the metallic packing against air leakage
during suction lift conditions.
There is a set of packing located in the packing
box end cover (fig. 6-3). The four flexible, metallic
packing rings are installed with the joints of abutting
rings staggered, and they are held in place by a pack-
ing gland. This packing gland is split to allow packing
replacement without disturbing the other elements of
the pump. The two sections of the packing gland are
held together with two screws, and the gland pressure
is adjusted with two gland nuts. This adjustment
should be sufficient to allow a slight amount of leak-
age past the packing for lubrication of the packing.
An inspection made while the pump is operating
discloses any leakage between the end covers and
case or in the piping connections. If leakage is ob-
served, it may be due to foreign matter on the gaskets,
defective gaskets, or loose nuts and bolts. Replace the
gaskets or tighten the nuts and bolts as required.
The pump does not require any lubrication, since
the oil being pumped lubricates all the moving parts.
Driving-unit lubrication instructions are provided
with each unit.