Customer: Ineos Manufacturing France SAS
End User: Ineos Lavera Refinery
Location: Martigues, Bouches-du-Rhône, France
Project: K101/102B compressor anchor bolt replacement, and partial regrout of motor baseplate and back bearing.
Work Period: 16 June to 20 June 2008.
1. ORIGINAL CONDITIONS
The machine in question is a Cooper-Bessemer KM-4, 4-cylinder gas compressor, built by Thermodyn around 1995/6. The first anchor bolt on the right-hand side of the crankcase (looking from the motor end) was broken at approx 630 mm below the top of the concrete foundation.
This appears to have taken place early in the operation of the unit in September 1997, probably due to fatigue fracture, as a result of hammering the bolt during installation to correct some misalignment. Since the bolt was welded to a baseplate at the end of the sleeve, this was the weak point. A repair which had been attempted in 2005 had failed. A new anchor bolt had been grouted into the sleeve with epoxy adhesive, but had again broken, near the top of the bolt stud, since no stretch length had been allowed.
As a secondary result of the broken anchor bolt, there was more oil leaking from this corner of the compressor, which had soaked into the grout surrounding the motor baseplate adjacent. This corner of the baseplate was vibrating, and needed regrouting to stabilize it.
The motor outboard bearing pedestal is mounted on a steel framework in common with the motor itself, but this is not well grouted to the foundation, and lacks stiffness. Due to the probable misalignment of motor and compressor shafts, there is considerable axial force transmitted back through the shaft, and the pedestal was moving visibly fore and aft.
2. REPAIR CARRIED OUT
The grout surrounding the broken anchor bolt was chipped out by pneumatic chippers. The initial stages were quite difficult due to the epoxy grout which had been used to carry out the 2005 repair. The original “grout-loc” soleplate was removed, and cannot be effectively re-used.