Timely trip of a LDPE hyper compressor

Hyper compressor plunger with markings caused by metal chips from packing

Machine data

Secondary high pressure compressor (Hyper) in Ethylene service for LDPE production

K12 Hyper compressor

Sequence of events

  • On March 29, the Hyper compressor was tripped by the PROGNOST system due to high plunger vibration on cylinder 2A
  • Vertical position  lead LDPE unit for total shut down
  • The Maintenance group, with the help of PROGNOST Systems Customer Support, analysed the data and recommended to open the cylinder for inspection
Trend over 60 minutes of plunger position Peak-to-Peak values

Findings

  • Chips of packing ring material were found in the plunger path way
  • The packing has made a heavy marking on the plunger at the large contact area
  • The packing cup was found to be damaged
Damaged packing of Hyper compressor
Hyper compressor plunger with markings caused by metal chips from packing

Conclusion

The PROGNOST system tripped the hyper compressor at the right time and avoided the costly consequences of secondary failures