We recently experienced a small fire in/around the exhaust system insulation box adjacent to cylinder A4 while the engine was operating. It continued on for about 15 minutes after the engine was tripped while being fought with a fire extinguisher. Wartsila tech determined it is likely a glycol fueled fire due to O-ring failure on a vertical support for A bank gas pipe. On an engine retest a mist was observed coming from the vertical support. We have pulled the vertical supports on A bank and over 50% look flattened or deteriorated, has anyone had a failure issue like this one?