Operation and Maintenance Manual
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2.3.3. Gauges
For the operation control, it is recommended to provide a compound gauge on the suction pipe line and a pressure
gauge at the pump casing or close to the casing on the discharge pipe line.
These gauges shall be able to indicate the pressure equivalent to about 150% of the maximum operating pressure.
Also, connect a gauge cock to each of these gauge.
When handling liquid containing suspensions or solid, attach suitable strainers. Further, to prolong the life of the
gauges, open the gauge cock only when reading pressure gauge, in other words, keep it closed all the times except
when reading the pressure.
2.3.4. Bearing
The pump shaft is supported with two single row deep ball bearings (3210, 63 series), which are srinkage-fitted in
the shaft and housed in the bearing case. These bearings are lubricated with high-grade bearing grease.
Periodic maintenance and inspection of the bearing is not required.
The maximum allowable temperature of the bearings is either 75
°
C on the outside wall of the bearing housing of
the room temperature plus 40
°
C.
3. Dismantling and Reassembling
3.1. General
Before overhauling, be sure to check that the pump is in absolutely unstable condition.
In addition, check without fail that the both suction and discharge line sluice valves keep full-close position, the
pump casing is normal in its temperature and no pressure is loaded to the pump casing (that is, the casing is empty).
When overhauling, maximum possible effort must be made to avoid accidental trouble. Also, good care must be
exercised to protect the pump components / parts from impact and flaw in handling of them.
3.2. Dismantling
For dismantling the pump, follow the disassembling sequence given below with reference to 3.5 “Exploded View”
and parts names listed therein.
(1) Remove any small piping if any.
(2) Remove the coupling guard.
(3) Remove the coupling and then remove the prime mover from the common bed.
(4) Unscrew off the nuts for casing cover and the bolts fixing support foot (1830) to the common bed.
(5) Pull out the casing cover and the bearing housing with rotating elements as assembled. In the case of large
size pump, hoist up the casing cover end or support it with a proper means to prevent the assembly parts from
turning a side.
(6) When some parts require replacement or repair according to their condition, take out those from the pump
shaft. When removal of such parts is difficult because of long term use of the pump, penetrate well-known
penetration oil or use a special tool. In any case, don’t hammer them.
(7) Follow “Exploded View“ for disassembling the parts / components. (Refer to 3. 5)
(8) When replacement of the ball bearings is required upon inspection, pull out the pump shaft with bearings fitted
on from the bearing case in direction to the prime mover and heat up the bearing only by acetylene gas. And
the bearing can be taken out from the shaft.
(9) After overhauling, check that various gaskets on the sealing surface are free from flaw and break, and replace
them with new one when required.
3.3. Reassembling
Reassemble the overhauled components and parts in the reverse sequence of the overhauling with reference to
“Exploded View“. For normal running of the pump, specially follow the precautions given below.
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