CYPRESS GAS PIPELINE COMPANY

Incident Narrative

AT 0200 PIPELINE CONTROL CENTER NOTICED A DROP IN PRESSURE ON BRW 1 PIPELINE NEAR THE BATON ROUGE GAS PLANT. PIPELINE CONTROL DISPATCHED A TECHNICIAN TO INVESTIGATE. TECHNICIAN ARRIVED ON SITE AT APPROXIMATELY 0310 AND FOUND A RELIEF VALVE RELIEVING TO ATMOSPHERE, VERIFIED PIPELINE PRESSURE WAS NOT EXCEEDING MAOP, AND CLOSED THE BLOCK VALVE UNDER THE RELIEF VALVE TO SECURE SITE. PIPELINE CONTROL CONTINUED MONITORING PIPELINE PRESSURE UNTIL A CERTIFIED TECHNICIAN ARRIVED TO MAKE REPAIRS. THE TECHNICIAN REPLACED THE PILOT ON THE RELIEF VALVE, SET NEW PILOT TO ESTABLISHED SETTING AND RETURNED THE SEGMENT TO NORMAL SERVICE. AT 0409 IT WAS DETERMINED THE VOLUME OF GAS RELEASED BY THE RELIEF VALVE EXCEEDED 3 MMSCF AND THE NRC WAS NOTIFIED AT 0419. VISUAL EXAMINATION OF THE RELIEF VALVE INDICATED FLUID BUILD-UP ON THE PILOT CAUSED IT TO RELIEF BELOW THE SET POINT. 48 HR. NRC NUMBER 1194628 INVESTIGATION OF THE RELIEF VALVE PILOT BY A THIRD PARTY VENDOR INDICATED THAT FLUID WAS PRESENT AND A FAILED O-RING SEAL WAS FOUND. THESE FACTORS CONTRIBUTED TO THE RELIEF VALVE LIFTING BELOW THE SET POINT. THE REPLACEMENT PILOT HAS BEEN OPERATING AS INTENDED FROM TIME OF INSTALLATION WITH NO ISSUES.