Field Survey of Compressor Train Case Study

Problem

The client hired KHE to investigate periodic high vibration in gas compressor train.

Solution

Using the integrated systems approach, KHE interviewed engineering, maintenance and operations personnel and performed vibration testing. Shortly after KHE became involved, the machine was shut down due to high vibration levels. Based on the data, KHE submitted a list of recommendations to be acted upon during the short shutdown, including piping support repairs, tightening of the anchor bolts, and realignment of the train, all of which the client completed. Following the shutdown, the machine did not exhibit the high swings of vibration levels noted during our vibration testing. However, while these changes improved the rotordynamic stability of the system, some problems remained. Although the machine, overall, did not exhibit the high swings in vibration prior to the shutdown, there were still high vibration levels at one bearing not previously inspected due to facility constraints. Subsequent rotordynamic analysis diagnosed specific problems with shaft dynamic unbalance. Therefore, the shutdown and repairs were necessary to isolate the root cause of the high vibration, which could not have been diagnosed until alternate causes were excluded.

Result

The dynamic unbalance was subsequently corrected. The compressor train did not develop the high vibrations. Subsequent vibration testing proved that the problem had been solved.