Session: DA-01-02 Design and Analysis of Pressure Vessels, Heat Exchangers and Components-2

Paper Number: 155552

155552 - Inspection and Analysis of Pressure Vessel With Combined Cui and Wet H2s Damage 

Abstract: 

A debutanizer tower in a Coker gas plant was inspected for Corrosion Under Insulation as a part of a Risk Based Inspection program. External corrosion found in the upper section of the tower was further inspected for remaining wall thickness where internal wet H2S damage was found (from the outside). Overlaid inspection results identified areas where external corrosion and internal wet H2S damage were overlapping and a Level 3 Fitness for Service analysis was started. Detailed inspection scanning aided in separating the damaged area into multiple zones although blister proximity required larger fields to be grouped together. Due to the size of blister fields, non-Post Weld Heat Treat base metal, structural discontinuities, and external corrosion, the Fitness for Service analysis became challenging to complete and the decision was made to take the equipment out of service for repair. The original tower section was removed and replaced with upgrades in a short duration outage. The original tower section was cleaned and internally inspected with Wet Fluorescent Magnetic Particle Testing to validate Phased Array Ultrasonic Testing data. After completion of the internal inspection, the tower section was hydrotested to original conditions to evaluate Fitness for Service  modelling assumptions provided by Phased Array Ultrasonic Testing.

Presenting Author: Jackson Pennell bp Cherry Point Refinery

Presenting Author Biography: 10 years' refining experience on the owner/operator side providing technical support to Operations, Maintenance, Turnaround, Integrity, Project, and Central teams. BS in Mechanical Engineering from the University of Washington.

Authors:

Jackson Pennell bp Cherry Point Refinery
Kevin M. Haley The Equity Engineering Group, Inc.
Jason Morris bp Cherry Point Refinery