SUNOCO PIPELINE L.P. — Hazardous liquid — incident on 2015-01-14

Hazardous liquid incident in BEAUMONT, JEFFERSON County, TX. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 30 HVL OR OTHER FLAMMABLE OR TOXIC FLUID WHICH IS A GAS AT AMBIENT CONDITIONS released, $597,569 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20150046.

Operator ID: 18718.

Reported incident date: 1/14/2015 16:20.

Location detail: 10229+08.4

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: ON 1/14/2015 A 30 BBL RELEASE OF PROPANE OCCURRED AT THE WEST PORT ARTHUR RD. MLV SITE ON THE MARINER SOUTH SYSTEM. A LOSS OF LINE PRESSURE WAS IDENTIFIED VIA SCADA IN THE CONTROL CENTER. THE LINE WAS IMMEDIATELY SHUT DOWN AND MLV'S ON EITHER SIDE OF THE AFFECTED SEGMENT WERE CLOSED REMOTELY BY THE CONTROLLER. FIELD PERSONNEL WERE DISPATCHED TO THE LOCATION TO INVESTIGATE. WHEN THE FAILURE LOCATION WAS IDENTIFIED AT A 3/4' PIPE NIPPLE THAT HAD CRACKED AT THE THREADED CONNECTION TO AUXILIARY PIPING AT THE MLV SITE IT WAS DETERMINED THAT THE LINE SEGMENT WOULD HAVE TO BE PURGED TO AFFECT PERMANENT REPAIR. PURGE WAS ACCOMPLISHED AND PERMANENT REPAIRS WERE COMPLETED AND THE LINE WAS RETURNED TO SERVICE ON 1/22/15. INVESTIGATION REVEALED THAT THE NITROGEN SUPPLY SYSTEM REGULATOR FOR THE PNEUMATICALLY OPERATED MLV FAILED WHICH CAUSED HIGH NITROGEN PRESSURE TO BE EXERTED ON THE PNEUMATIC ACTUATOR. THE HIGH PRESSURE ON THE ACTUATOR CAUSED IT TO FAIL AND IMPACT THE ADJACENT AUXILIARY PIPING AT THE MLV SITE. THIS IMPACT BENT THE PIPING ASSEMBLY AND ULTIMATELY CAUSED THE CRACK OF A 3/4' PIPE NIPPLE AT THE THREADED CONNECTION. THIS CRACK WAS THE SOURCE POINT OF THE RELEASE OF PROPANE. THE PERMANENT REPAIRS INCLUDED INSTALLATION OF A DUAL REGULATOR AND A PRESSURE SAFETY VALVE (PSV) IN THE NITROGEN SUPPLY SYSTEM FOR THE PNEUMATICALLY OPERATED MLV. THIS CONFIGURATION WILL RELIEVE NITROGEN PRESSURE SHOULD THE REGULATOR FAIL THUS PREVENTING A REOCCURRENCE OF THIS FAILURE SCENARIO.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: EQUIPMENT FAILURE — MALFUNCTION OF CONTROL/RELIEF EQUIPMENT.

PHMSA indexed costs: $670,000 reported total cost, $336,116.773 in 1984 dollars, $827,752.167 in current-year dollars.

PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.