Failure analysis of oil immersed screw compressor with analytical ferrography and vibration

Sunil Tiwari, Manager Engineering Reliability, OPGC


High axial and radial vibrations in screw compressors , high air end outlet temperatures and failing of bearings of screw air compressors and motors bearings was critical problems.

Following Observations were noticed in oil analysis of screw air compressors
1. Service air compressors oil viscosity is increases up due to premature failing of lube due to thermal
cracking and in presence of extremely high moisture content . Lube is becoming thick/gaining viscosity.
Viscosity increase leading to viscous drag and lubrication delay on the compressor bearings which is
creating rotor imbalances and leads to severe bearing wear out

1. Effective preventive maintenance of the screw compressors with regular air filter replacement ,
bearing oil filter replacement , oil separator replacement and inspection and cooling of coolers.
2. Timely replacement of vibration isolating dampers.
3. Overhauling of screw compressors at regular interval at site

1. How to utilize multiple condition monitoring techniques to understand the failure modes.
2. Failure modes in oil screw compressors.
3. Analytical ferrography utilization for understanding the different failure mechanisms of rotating equipment.


Bachelors in Mechanical engineering and proficiency in Physical asset management, predictive maintenance and preventive maintenance. 10 years + experience in establishing preventive and predictive maintenance programs, contract management and implementation in large size coal based power plant and non metal industry. Hands on experience in vibration analysis , analytical ferrography ,motor current signature analysis of motors up to size 5400 KW, centrifugal and axial pumps, axial and radial fans, gearboxes and steam turbines.