Sanya Mathura of Strategic Reliability Solutions Ltd
A client wanted to extend the life of the oil in service by a further 6 months past the routine change date. This would allow them to complete their required level of productions to fulfill their customer’s orders. The extension of the oil life is carded to take place on their critical pieces of equipment for Train B (a series of 6 GE Frame 5 Gas turbines).
More background: The facility produces liquefied natural gas and has 4 trains each consisting of 6 or 7 GE Frame 5 turbines. Each train was commissioned separately and are treated as separate units with differing dates for end of service life. After seven years, each train is recommissioned with new turbines and a full overhaul completed on the entire train. For Train B, the time was approaching for the mandatory overhaul however, the company needed the extra capacity to fulfill customer orders. As such, it decided to extend the service life of the equipment on the train but needed to ensure that the lubricant could withstand the additional time and perform successfully.
Baseline samples were taken from each of the turbines (critical units) on the train to establish the current condition of the lubricant in service. The following tests were performed; MPC, RPVOT, RULER, Viscosity, TAN, Tests for contaminants (including ISO 4406), additive packages and wear metals. It was found that the wear metals were considerably low which indicated that there