Unit: Waukesha 7042GL – Worthington Super CUB 2 throw frame. Package designed for 1000 RPM operation.
Over the life of the machine, the field conditions changed and production demands increased. Based on manufacturer input, both the driver and the compressor frames are rated for 1200 RPM operation. Based on this information, the unit was sped up to 1200 RPM. Due to the increased speed and changes in operating pressures, acoustical issues were encountered where vibration levels spiked to dangerous levels on the 1st stage suction system.
This unit was on a regular condition based maintenance (CdM) program where vibration levels were measured along with various other parameters to quantify overall skid health and reliability. The EMSi analyst was able to evaluate the severity and have the issue addressed immediately. Operations was instructed to have the unit operating speed adjusted to reduce the levels to an acceptable range until a permanent solution could be devised. A subsequent completed vibration study was completed and the unit was modified to allow for the wider operating envelope desired.
Vertical Suction Bottle Vibration after changes in field conditions:
This is an example of potential results where changes in unit operating conditions can have a serious adverse effect on unit condition and reliability. By implementing a Condition Based Maintenance program, this client was able to avert a potential catastrophic failure on this piece of equipment that would have meant an entire plant site was down with two 1450 plus horsepower machines sitting idle while necessary repairs could be completed. Resulting damage could have been significant as this suction bottle sits less than two feet away from the engine turbochargers and the resultant damage from gas leakage due to a bottle failure may have been a total unit loss of property and potentially life of the operations staff.