In our GE Fram 5 unit we found out after lap analysis that some liquid fuel has been leaking inside of the lube oil tank. We drained the tank and checked the inner parts of the tank, especially the drain box for any cracks and everything was OK. We made sure that all of flanges and sealed and tightened.

Any help with be appreciated

 

ibrahimdowa,

Typically there aren't any liquid fuel lines running through the L.O. Tank--just to prevent this kind of problem (contaminating the L.O. with liquid fuel). So, it should be possible to follow all liquid fuel lines outside of the tank and see that none enter/exit the tank.

Having said that, there are a couple of places where it might be possible (not likely, but possible) for liquid fuel to somehow get into the L.O. system. One would be the hydraulically-operated Liquid Fuel Stop Valve. It might be possible for the valve seals to leak and possibly allow liquid fuel to enter the hydraulic oil drain line--not likely, but a distant possibility.

And, the liquid fuel bypass valve; it might be possible for leaky seals to allow liquid fuel to get into the hydraulic oil drain line.

You need to review all of the piping and components to see if there's any possibility for liquid fuel to leak into the oil system (such as the liquid fuel stop valve and the liquid fuel bypass valve). I believe most high-pressure liquid fuel pumps have their own L.O. sump and don't use turbine L.O. for lubrication--but that doesn't mean some packagers haven't used turbine L.O. for high-pressure liquid fuel pump lubrication. If any of the liquid fuel piping enters/exits the L.O. tank that needs to be checked; porous welds have been known to leak small amounts of liquid over time.

However, I've seen more than one site use empty oil drums for storing liquid fuel and for a well-meaning person to unintentionally pump liquid fuel from one of these oil drums--which wasn't properly labeled/marked and left in the oil drum storage area!--into the L.O. tank when topping off the L.O.

Please write back to let us know what you find.