KIRLOSKAR 65-DSM 315M, Instruction On Installation, Operation And Maintenance

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FOOT VALVE
It is advisable to install a foot valve to facilitate priming. The foot valve should have sufficient clear
passage for water. Care must be taken to prevent foreign matter from being drawn into the pump or
choking the foot valve and for this purpose an efficient strainer should be provided.
STUFFING BOXES AND PACKING
Stuffing boxes should be carefully cleaned and the packing placed in them. Be sure that sufficient
packing is placed at the back of the water seal cage. If the water to be pumped is dirty or gritty,
sealing water should be piped to the stuffing boxes from clean outside source of supply in order to
prevent damage to the packing and shaft. In placing the packing, each packing ring should be cut to
the proper length so that ends come together but do not overlap. The succeeding rings of packing
should not be pressed too tight as it may result in burning the packing and cutting the shaft. If
stuffing box is not properly packed, friction in stuffing box prevents turning the rotor by hand. On
starting the pump it is well to have the packing slightly loose without causing an air leak, and if it
seems to leak, instead of putting too much pressure on the gland, put some heavy oil in the stuffing
box until the pump works properly and then gradually tighten up the gland. The packing should be
occasionally changed.
BALL BEARINGS
Correct maintenance of ball bearings is essential. The bearing manufacturers give the following as a
guide to relubrication periods under normal conditions.
Three monthly when on continuous duty.
Six monthly when on eight-hour per duty.
The bearings and housings should be completely cleaned and recharged with fresh grease after 2500
hours or the nearest pump overhaul time.
PRIMING
No pumping action occurs unless the pump casing is filled with liquid. Pump casing and suction pipe
must therefore be completely filled with the liquid and thus all air removed before the pump is started.
Several different priming methods can be used depending on the kind of installation and service
involved.
(1) Liquid level above pump level
Pump is set below liquid level of source of supply so that liquid always flows to pump under positive
head.
(2) Priming with foot valve
(a) When pump is installed on suction lift with foot valve at the end of suction line, fill pump
with water from some outside source till all air is expelled and water flows through air
vent.
(b) When there is liquid under some pressure in the discharge pipe, priming can be effected
by byepassing the pressure liquid around the check and gate valve. Of course, the initial
priming must be effected from some outside source.
NOTE: in this case, the foot valve must be capable of withstanding pump pressure and
possible surge.
(3) Priming by ejector: An ejector operated by steam, compressed air or water under pressure and
connected to air vent on top of casing can be used to remove air from and prime the pump on
suction lift installations.
(4) Priming by dry vacuum pump : a hand or power pump sucks in all the air from the casing and the
suction pipe, and thus primes the system.
STARTING
The pump must not be started without being primed. Be sure that the driver rotates in the proper
direction as indicated by a direction arrow on the pump casing.
RUNNING
On account of its simple construction, the centrifugal pump requires practically no attention while
running. Lubrication of the bearings and manipulation of the glands are the only things that need
attention from the operator.
STOPPING
Before stopping the pump, close the gate valve. This will prevent water hammer on check valve.
STUFFING BOXES
Do not tighten the glands excessively. A slight dripping of water from the stuffing boxes when pump
is running keeps packing in good condition.
CASING RINGS
Casing rings are fitted in the casing to reduce the quantity of water leaking back from the high
pressure side to the suction side. These casing rings are fitted to maintain a small clearance and
depend on the water in the pump for lubrication. When they are worn out, the clearance becomes
greater and more water passes back into the suction. They must be replaced from time to time to
restore the pump efficiency to its normal value.