Application

- Thomasen piston compressor
- 2 throws, 2 stages
- Medium: Hydrogen
- Capacity control: HydroCOM
The compressor has a „Free Floating Piston“ system with non-lubricated cylinder (for lifetime optimization of rider rings) and a mini-lube stuffing box seal. This machine combines the Free Floating Piston system with a Hoerbiger HydroCOM flow regulation. Since the initial compressor start, the piston rings of both stages reached only short operation lifetimes of 1,500 hours and with a decreasing tendency:
Lifetimes before replacement of piston rings of the 1st stage
- 1,850 hrs
- 707 hrs
- 891 hrs
- 801 hrs
- 1,607 hrs
Lifetimes before replacement of piston rings of the 2nd stage
- 3,773 hrs
- 4,006 hrs
Preliminary PROGNOST® data analysis: Detection and location of the problem


- Expansion and compression lines of the p-V diagrams of stage 2 HE (head end) and CE (crank end) are different from normal patterns
- Stage 2 CE side: Breakthrough suction pressure is earlier than expected and Re-expansion and compression lines are steeper than normal
- Stage 2 HE side: Breakthrough suction pressure is later than expected and Re-expansion line is steeper than normal and compression line is flatter than normal
→ On the CE side: Possible suction valve leaking; possible piston ring leakage
→ In the HE side: Possible piston ring leakage from the CE side
Findings

