3. MAINTENANCE AND INSPECTION
3.1 General
(1) During operation, the temperature will rise corresponding to the compression ratio due to compression
heat. However, if the temperature rise is local and the outside coating scorched, it is abnormal.
It may be because of the improper Cooling water supply or Cooling water cut-off, interference of Screw
with casing or the pump has sucked in some foreign material. Therefore, stop the operation immediately
to check the condition.
In some case, the Screws and the casings might have corroded through a long time operation, which will
make the clearance between these parts larger and return discharge gas to suction side in large
quantities, the pumping capacity of the pump becomes decrease than it was initially planned as a result.
In such cases, the air quantity will be decreased in due course. Then, stop the pump and take
measurements of the clearances for any consideration of corrective action to take.
(2) Abnormalities can be noted immediately by making routine checks on bearing temperature, vibration or
noise. Therefore, utmost care should be necessary for daily inspection.
(3) Interference between Screws or between Screw and casing can be noted be listening to any sound
through stethoscope applied against the casing. So, make checks from time to time.
(4) In winter, in cold regions, whenever the pump is stopped, let cooling water drained. Freezing of water
could damage the jacket.
3.2 Periodical Inspection
●
Daily
①
Oil-Level Gauge : Excess or short lubricant can damage gears and bearings.
②
Check that the amount of cooling water is adequate.
③
Check the temperatures of Grease cover and Front End Cover.
Use of a suitable thermometer or a surface thermometer will be convenient.
④
Check the suction and discharge pressures. To check these pressures, make sure that the operation
of the pump is within plan specifications.
⑤
Check a load on the motor.
Be noted that an increase in the motor load indicates some kind of abnormality.
●
Monthl y
①
Check tension of V-belt.
②
Check lubricant color.(If, Oil color is dark, replace lubricant).
③
Check Oil level. If Oil disappear severely, check Mech. Seal.
●
Quarterly
Check Cooling water flow & color. If something wrong, clean water jackets and water piping.
Check grease in the Rear End Cover. Refill grease, if necessary.
●
Every 6 Months
①
Check pipe supports for the pump.
②
Replace lubricant in the Front End Cover.
③
Replace grease in the Rear End Cover.
●
Yearl y
①
Check Mech. seals
②
Check inner surface of Screws and casings.
Disassemble the piping on suction side to check the inner surface of Screws and casings.
③
Check the gears - Remove the Front End Cover to check the gear.
