Refinery FCC Unit Abrasive Waterjet Cutting

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Refining - Abrasive Water Cutting
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A major refinery on the Gulf Coast had a very dangerous situation on its hands. One of the manway covers on its FCC tower was leaking hot gasoline and emitting H2S vapors – creating significant safety and environmental concerns. The refinery engaged a leak repair contractor and Veolia's Industrial Solutions & Services team in Port Arthur, Texas, to develop a permanent solution. 

The manway was over 100 feet in the air and accessible only by a vertical ladder. It is surrounded by a small walkway area that was the only available space to conduct the operation. The unit was operating at 150 degrees and 125 PSI, and although the plant had temporarily stopped the gasoline leak, the manway was still emitting LEL vapors, creating a significant ignition risk and danger to workers. 


Unwilling to expose its employees to such dangerous working conditions, Veolia needed to develop an alternative repair solution that would better protect worker safety, mitigate the environmental hazards, and permanently seal the manway cover to eliminate future leaks until the refinery's next FCC unit turnaround, which was several years away. The FCC unit remained online during the entire operation. 

Working in close coordination with the customer, Veolia proposed an alternative approach  that would involve the leak repair company first temporarily sealing the manway cover to achieve zero LEL emissions. The leak detection contractor used a wire wrap technique to seal off the hazardous emissions. At Veolia's request, they used studs with exposed threads that the contractor would utilize to mount a permanent clamp. After the leak repair company contained the leaking gasoline and H2S vapors, ignition risks were eliminated. A crane support with a man basket, personnel and abrasive waterjet equipment was raised up to the work area. The presence of the crane also created a secondary exit point from the work area to remove workers if the environment became dangerous during the repair. 

Veolia was able to begin safely performing abrasive water cutting to clear the area of structural brackets and an I-beam that obstructed mounting the permanent clamp on the manway without fear of sparks igniting a fire on the unit. 

Veolia's custom built shield for the FCC unit was positioned into the area between the vessel and the cutting points to protect the FCC unit from potential water cuts. Then one of Veolia's experienced water cutting operators performed four major cuts to clear obstructions for the permanent clamp to be installed by the leak repair company. 


With the water cuts complete, removing obstructions on the tower, the leak repair contractor was able to safely install the permanent clamp over the manway, and the repair project was successfully completed.

From the customer's perspective, Veolia's solution for this repair added value far beyond cost in three significant ways. Most importantly, Veolia designed this project's solution to keep workers out of harm's way by eliminating the emissions risk that could have resulted in an explosion and seriously damaged the refinery. Secondly, by helping the contractor permanently seal off the vapor emissions, the plant avoided any short or long-term environmental compliance issues related to the leak. And lastly, the repair work was completed while the FCC unit remained fully operational–helping the refinery avoid millions of dollars in unscheduled downtime.