INTERCONTINENTAL TERMINAL COMPANY, LLC

Incident Narrative

AT 16:30 AN ACT ASSOCIATE WAS GAUGING OFF CHEM GRADE PROPYLENE PRESSURE VESSELS WHEN HE HEARD A NOISE ON TOP OF V-204. THE LEAD OPERATOR WAS IMMEDIATELY INFORMED VIA RADIO. THE LEAD OPERATOR AND ACT ASSOCIATE MET ON TOP OF V-204 TO INVESTIGATE FURTHER AND IDENTIFIED A LEAKING SAFETY VALVE. THE VALVE WAS ISOLATED AND THE LEAK STOPPED AT 16:35. IT WAS DIFFICULT TO INTERPRET THE ROOT CAUSE OF THE EVENT DUE TO A NUMBER OF VARIABLES THAT IMPACT THE PRESSURE ON V-204. THE MAIN METHOD OF ROOT CAUSE INVESTIGATION WAS THROUGH ELIMINATION. VESSEL TEMPERATURE IS HAND RECORDED ONCE PER DAY BY READING A LOCAL TEMPERATURE GAUGE PLUS IS RECORDED ANY TIME A TRANSFER INTO OR OUT OF THE VESSEL IS RECORDED. TANK GAUGED LEVELS ARE ALSO RECORDED AT THIS TIME. THERE IS NO CORRELATION BETWEEN MAXIMUM PRESSURE ON AUGUST 5 AND THE MAXIMUM TANK TEMPERATURE DURING THE 24 HOUR PERIOD OF AUGUST 5. PIPELINE PRESSURE OPERATES SIGNIFICANTLY HIGHER THAN THE 150-250 PSIG OF THE CHEM GRADE PROPYLENE BULLETS. WHILE THERE WAS A SMALL SPIKE IN THE PIPELINE PRESSURE AT THE TIME OF THE INITIAL RELEASE (≅1220 PSIG VS. 1200) IT WAS PROBABLY NOT THE CAUSE OF THE INCREASED BULLET PRESSURE. THERE WERE OTHER TIMES WHEN THE PIPELINE PRESSURE WENT UP TO 1220 PSIG WITH NO INCREASE IN BULLET PRESSURE. C2/LIGHTS CONTAMINATION IN THE CHEM GRADE PROPYLENE PIPELINE WAS ACTUALLY RUNNING LOWER THAN NORMAL AND MUCH LOWER THAN THE SPECIFICATION OF 1000PPM. LIGHTS WERE NOT A CONTRIBUTING FACTOR TO THE OVERPRESSURE OF THE PRESSURE OF V-204. V204 LIQUID LEVEL WAS AT THE UPPER END OF NORMAL WORKING RANGE LIMITS. THERE WERE OTHER TIMES BEFORE AND AFTER THE PRESSURE EXCURSION WHERE THE VESSEL LEVEL WAS HIGH BUT DID NOT OVERPRESSURE. THE HIGH LEVEL MAY HAVE BEEN A CONTRIBUTING FACTOR ASSUMING THE ROOT CAUSE WAS NON-CONDENSABLES (SUCH AS NITROGEN) IN THE VESSEL AND THERE WAS LESS AVAILABLE SPACE FOR AN ABNORMAL INERT IN THE SYSTEM CAUSING AN INCREASED PRESSURE. CONCLUSION: THE ROOT CAUSE OF INCREASED PRESSURE IN V-204 TO CAUSE THE RUPTURE DISC/JPV-3400 TO OPEN WAS INERTS/NON-CONDENSABLES COMING IN THROUGH THE CHEM GRADE PROPYLENE PIPELINE. ADDED 2/2/17 PER RUPTURE DISC ANALYSIS, RUPTURE DISC OPENED DUE TO OVERPRESSURE AS IT WAS DESIGNED TO OPERATE. NEW, REPLACEMENT RUPTURE DISCS FOR ALL PROPYLENE BULLETS ARE ON SITE, AWAITING OPPORTUNITY TO SCHEDULE INSTALLATION. FINAL UPDATE TO ACCIDENT REPORT BY TINA MURRELL, ITC