Respondent owned and operated a petroleum refinery and it’s RMP lists covered processes subject to Program 3 requirements, including the Ultracracker (ULC) unit which consists of three sixty-three-foot-tall pressure cylindrical reactors, each containing five individual catalyst beds. The hydrocracking reaction converts the larger hydrocarbon chains into smaller, more valuable hydrocarbons. On March 10, 2018, operators were returning the ULC to service after a turnaround that included maintenance (e.g. START-UP after maintenance) on the E-103 effluent exchanger. At 8:50 AM on March 10, 2018, a component of the E-103 effluent exchanger, the 127 J pump, tripped off. Operations personnel were able to restart the pump and return flow to normal rates, but the pump tripped off again at 9:10 AM and operations personnel were unable to return flow rate to normal. Operators decided to shut down the ULC process and depressured the unit to the flare at 9:59 AM. Operators identified a leak at the channel-to-cover plate flange on a component of the E-103 effluent exchanger, the I 03-CC2 exchanger.
The leaking gasket was a double rail gasket, the design of which requires the inner gasket to be the primary seal while the outer gasket serves as a spacer to optimize bolt loading and gasket stress. To work properly, the inner gasket must contact the closure plate first. Upon inspection of the flange, operators discovered that the outer gasket was approximately twenty millimeters (approximately 0.79 inches) too thick, which prevented the inner gasket from sealing.
Approximately 3,325 pounds of process materials were released during the leak, including 1,521 pounds of methane, 768 pounds of hydrogen, 306 pounds of propane, 288 pounds of ethane, 120 pounds of isobutane, 100 pounds of pentane plus, 91 pounds of hydrogen sulfide, 68 pounds of n-Butane, and 63 pounds of i-Pentane. Respondent determined that during the turnaround, operations personnel inadvertently measured the outer gasket’s width from the wrong location, resulting in the ordering, installation, and use of an inappropriately-sized outer gasket. Respondent asserts that when performing measurements, Respondent relied on deficient measurement instructions provided by the manufacturer of the double rail gasket.
Count 1, Failure to Assure Suitable Materials Pursuant to 40 C.F.R. § 68.73(f)(3), the owner or operator shall assure that maintenance materials, spare parts and equipment are suitable for the process application for which they will be used.
Respondent failed to assure that maintenance materials, spare parts and equipment are suitable for the process application for which they will be used by installing an incorrectly sized outer gasket in the I 03-CC2 exchanger.
Respondent’s failure to assure that its maintenance materials were suitable for the process application for which they were used constitutes a violation of 40 C.F.R. § 68.73(f)(3).
Accordingly, pursuant to Section 113(a)(3) of the CAA, it is agreed that Respondent, which has consented to the terms of this Order, shall comply with the general duties to identify hazards, design and maintain a safe facility so as to prevent releases, and mitigate releases that do occur as follows:
- Within 90 days of the effective date of this Order, Respondent shall:
- Certify that Respondent has created a management of change procedure for heat exchanger gasket design.
- Submit a plan and implementation schedule for re-measurement of outer gasket locations on all ULC high pressure exchangers using the dual rail gasket design. The implementation schedule submitted pursuant to this Order may be adjusted following submission to account for modifications to the corresponding turnaround schedule.
- Respondent will notify the double rail gasket manufacturer (Advanced Sealing) concerning the lessons learned from incident investigation report number I65228.
CLICK HERE for the report