Rubber Bladder Puncture - A case Study

In this paper, oil analysis program was set up to monitor a 500 kV rubber bladder sealed reactor unit, belonging to Salto Grande (Uruguay). The unit filled with paraffinic uninhibited oil was in service for 35 years. Oil sample analyses, including dissolved gas analyses (DGA), acidity, interfacial tension (IFT), dielectric losses, breakdown voltage, moisture content, furans content, color, particle content and oil temperature were periodically performed to monitor the condition of the unit. Even though nitrogen (N
₂
) concentration on phase B of the unit indicated leakage, the oxidation indicators did not show any sign of degradation. The results indicate a 5 years delay between N
₂
/air ingress and acidity increase. Accurate monitoring is therefore recommended close to the theoretical design life of the bladder.