Original Date: 08/26/1996
Revision Date: 01/18/2007
Best Practice : Vessel Assembly and Changeout Planning
WSC purchased a new furnace vessel for the Basic Oxygen Plant (BOP) in the third quarter of 1989. This vessel was needed to replace one of two existing vessels in the BOP, and was critical to operations which required two vessels to be continuously operated on an alternate, rotating basis. The fabrication specifications of this new vessel required that it be delivered to WSC for assembly with minimal fitting and welding requirements. To accomplish this and ensure a timely assembly and changeout of the old vessel without delaying plant operations, a team of WSC personnel was formed to develop a detailed process plan to identify every step of the operation required, from receipt to final assembly and changeover. This team represented all trades involved in the process. In addition to developing the process plan, individual team members performed as job leaders during their phase of the operation.
To document and manage the numerous steps involved in the assembly of the vessel as well as the changeout operation, the project team leader used the PC-based software package, Primavera. Use of this system helped to ensure that milestones and key events were accomplished as scheduled. This approach also allowed for the creation of historical data that can be used with photographs and videotapes for future vessel changeouts.
Appropriation for funding of this project was developed and approved in March 1992 for $3.1 million. The assembly phase started in April 1992 and was completed in November 1992. All work was accomplished by WSC personnel and was completed one day early and under budget.
Changeout of the old vessel began on December 26, 1993 and was completed by the end of January 1994. The team was divided into two teams to provide around-the-clock coverage. Twice-daily meetings were held by the teams to update the status and to ensure no roadblocks developed. Face-to-face turnover by the two teams each day ensured that every detail was clearly understood and acted upon as scheduled.
Since the new vessel has been put into service, there has been no measurable distortion between the trunnion ring and the body shell. This is an indication that the useable life of this vessel is well on its way to meeting the 25-year service life requirement.
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