Valero Energie’s Jean-Gaulin refinery, located in Lévis, Quebec, wanted to replace the main flare, erected in 2006 (54″ diameter x 300′ high). 

Norda Stelo’s mandate was to evaluate the various construction options, considering health and safety and the reliability of production operations, while limiting any potential inconvenience to the community. The three possible options were:  

1. Complete flare replacement during a planned shutdown 
2. Installation of a temporary flare to allow replacement during normal operation 
3. Installation of a second flare in parallel with the existing one 

Norda Stelo then carried out the detailed engineering for flare replacement during a planned shutdown (option 1). 

As the timeline was limited due to the expected time for the planned shutdown, our team coordinated the engineering and fabrication of the flare with the manufacturer and construction contractor to receive a complete piece of equipment that exactly fit the existing layout to ensure that the replacement was possible within the given timeframe.  

Some technical optimization improvements were incorporated into the replacement to modernize the plant. After analysis of the various options, the new flare was manufactured with a stainless steel lined section to improve its service life for the next cycle. 

Buildability and schedule: 

The Norda Stelo team had to plan the steps required to dismantle the existing flare and replace it, in collaboration with Valero and the contractor. The planning of the work was of strategic importance, as the period allowed to proceed was limited and time defined. The planned shutdown was scheduled for 32 days.  

All the work that could be done without disrupting regular production was carried out in the preparatory phase: structural verification, surveys and 3D scanning of new and existing equipment, coordination of flare engineering and manufacture with the manufacturer, coordination with hoisting crane crews, drawings and work instructions for dismantling the existing flare, and assembly of the new flare on the ground. 

Studies and calculations were carried out to reduce the time required to safely dismantle the existing flare stack. The original chimney had been built in five sections. To reduce the work and downtime schedule, Norda Stelo’s study confirmed that dismantling the chimney in two sections of 150 feet each was possible with special lifting measures. 

Natural gas consumption: 

For greater efficiency and to reduce the amount of natural gas consumed, Norda Stelo proposed improving the purge gas control logic by adding certain valves and instruments. With this change, gas consumption could be greatly reduced, 6 months a year.

Although option 1 represented a greater challenge to achieve in a short timeframe, and put the restart of the refinery after the major shutdown at greater risk, option 1 was chosen in conjunction with the customer because it was more socially acceptable in the community. Adding a 2e flare would have simplified scheduling issues and improved operational flexibility, but it would also have brought with it the management of a new risk with the community (noise & new flame close to neighbouring neighbourhoods). 

Detailed planning of the replacement process in collaboration with Valero and the contractor enabled the work to be completed within the planned shutdown period. Everything that could be done upstream, such as surveys, fabrication of the new flare, and civil engineering work for the lifting cranes, was completed on schedule.  

The flare replacement also included a change in nozzle technology, enabling Norda Stelo to optimize purge gas control by eliminating natural gas consumption at certain times of the year. This optimization resulted in a 5-6 fold reduction in annual natural gas consumption, from an average of 29,000 scfh to 5,000 scfh.

• Option study and detailed engineering for flare replacement. 

• Surveying and 3D scanning before and during construction. 

• Analysis of the constraints involved in dismantling the existing chimney in as few sections as possible to reduce shutdown time. 

• Analysis of concrete foundations for equipment and anchors, in accordance with the NBCC update. 

• Replacement of strategic equipment within a very limited timeframe. 

• Careful planning of replacement stages and material manufacture and delivery to eliminate time lost during replacement. 

• Work in collaboration with Valero and the contractor to optimize the stages of completion. 

• Virtually complete assembly of the new flare on the ground for erection in a single stage, speeding up the process and minimizing overlapping work. 

• Electricity
• Instrumentation, Controls and Robotics
• Processes
• Structure
• Civil Works
• Piping and Pressure Vessels