Preventive maintenence of roots, diffusion and vane pump

1. Preventive measures for
pumps
By :
M. Mohsin Raza
Senior Engineer

2. What is maintenance ?
 Maintenance refers to a set of processes and
practices which aim to ensure the continuous
and efficient operation of machinery,
equipment, and other types of assets of
industry. Diligence in implementing an
effective maintenance program is essential to
the successful performance and longevity of
machinery, assets, facilities, and entire
industry.

3. What to do in maintenance?
Functional
Checks
Servicing
Repairing
Replacing
Devices
Equipment
Machinery
Infrastructu
re
Supporting
Utilities

4. MAINTENANCE STRATEGIES

5. PREVENTIVE MAINTENANCE
 Preventive maintenance is the act of
performing regularly scheduled
maintenance activities to help prevent
unexpected failures in the future. Put
simply, it's about fixing things before they
break.

6. WHY PM IS SO IMPORTANT ?
1. Lengthen asset lifespan
2. Lower risk of breakdowns
3. Increase efficiency
4. Decrease unplanned downtime
5. Promote health and safety
6. Boost customer satisfaction
7. Save money

7. PREVENTIVE MAINTENANCE OF VACUUM PUMPS
 Roots pump
 Vane pump
 Diffusion pump
 Dry screw pump

8. WHAT TO DO FOR PM OF VACUUM PUMPS
 Be Organized and Document Everything
 Oil Changes and Inspection
 Oil Leakage
 Drive Belts and Couplings
 Ultimate Vacuum Test
 Bearings
 Internal Inspection and Cleaning

9. BE ORGANIZED AND DOCUMENT EVERYTHING
 Generate a checklist
 Incorporate a maintenance log
 Arrangement of spare part

10. CHECK LIST FOR MAINTENANCE OF VACUUM PUMP

11. OIL CHANGES AND INSPECTION
 Oil contamination with vapor/condensate
 Hydrocarbon based /silicon based oils
 Oil change interval/level
 Indicators of the oil to be changed
 A dark appearance with or without the evidence of
particulates
 Inability of the pump to reach its ultimate vacuum with the
inlet valve closed
 A milky appearance, an indicator of water/moisture
present in the system

12. OIL LEAKAGE
 Differentiate oil films vs oil leakage
 Common sources for oil leakage
 shaft seal
 oil level windows
 drain valve/cap
 Especial importance to shaft seal

13. DRIVE BELTS AND COUPLINGS
 Examine for cracks, always with the pump
turned off and locked out
 The belt surfaces should be dry and free of
oil Inspect the interior of the belt guards for
dust generated by belt wear. If the belt is oily,
this can indicate a leaking shaft seal

14. ULTIMATE VACUUM TEST
 Close the inlet valve, operate the pump and
check the pressure between the valve and
the pump
 This will be the ultimate vacuum, and is a
good overall check of the pump condition
 Checking the amperes on closed valve
condtion
 Keep record for this test run for future
references and root cause analysis.

15. BEARING
 Gradual wear may allow a shaft position to
change slightly until rubbing develops
between the screws or rotors, or the impeller
and pump housing causes spot heating
 Sudden bearing failure is usually more
serious
 extensive general damage to casing and
gears is likely to occur immediately after the
bearing fails

16. INTERNAL INSPECTION AND CLEANING
 Vacuum pumps should be dismantled and
inspected after every 3000 hours of operation
 Vane pump should be checked for vane
crack/wear tear. If required should be changed
as entire set.
 Diffusion pump should be checked for
contamination of nozzles and build up of
deposits.
 Common industry practice for cleaning diffusion
pumps is to use acetone and then an isopropyl
alcohol rinse to clean internal pump components

17. CHECK VANES FOR DAMAGE/CRACK

19. SPECIFIC PREVENTIVE MAINTENANCE CHECKS FOR
ROOTS BLOWERS
 Required pressure achievement
 Current (amp) consumption is normal
 Noise
 Temperature of chasing
 Vibration
 Lubrication

20. PERIODIC CHECKS FOR ROOTS BLOWERS