Refinery Pipeline Decontamination and Reuse

Refining - Pipe Decon Header

PIPELINE DECONTAMINATION REPURPOSES EXISTING FUEL LINE TO ENHANCE REFINERY OPERATIONS

Refining - Pipeline Decontamination and Reuse
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Veolia was asked to safely convert an existing fuel gas piping system into an instrument air piping system. The process required chemically cleaning the pipeline with foam-core scrubbing pig devices to decontaminate the pipe system so that it could be repurposed to power ancillary equipment. 


The above-ground, carbon steel pipeline was 850 feet long and 6 inches in diameter. Veolia was challenged to utilize air-propelled pig scrubbers to remove loose rust scale and residual LEL vapors in the line. The conventional method of heating and recirculating cleaning water through the pipeline could not be used due to the busy roadways surrounding the pipeline that prevented laying feed hoses on the ground. Instead, Veolia would have to rely on using scaffolding structures and fabricating and installing additional piping, valves and fittings to conduct the cleaning. 


SOLUTION

Veolia's team of five crew members began the project by fabricating and installing piping, valves and fittings as required to circulate the pigs and clean the pipeline. Veolia brought in a tanker of warm condensate at one end of the piping system where the pigs would be launched from. Next, Veolia mixed 1,500 gallons of water with a 3% of volume CC Eliminator solution in their mobile circulation unit.

Veolia loaded one 6’’ medium density wirefoam pig followed by one medium density bare foam pig into the system. Veolia propelled both pigs down the piping system at approximately 90 GPM, or one foot per second, using the chemical solution until the circulation unit was empty. The pigs and wastewater were recovered at the end of the pipeline system with a vacuum truck. This process was repeated, reaching completion after four cleaning passes. Next, two medium density foam pigs were propelled with a decontaminating surfactant through the system and the LEL level was checked at several high point vents in the system. Veolia hauled the resulting wastewater by vacuum truck to the refinery’s on-site treatment plant. 

RESULT

With employees working across two shifts, Veolia successfully decontamined the refinery’s pipeline, saving the customer hundreds of thousands of dollars that would have been required if they had to build an entirely new pipeline to transport the instrumentation air. The pigs utilized were able to compress and decompress to manuever through both 45-degree and 90-degree bends in the piping.  
 
The piping system was successfully converted from fuel gas to an instrument air line that will now deliver clean air to operate numerous calibrated instruments and ancillary equipment throughout multiple refinery units. In total, the project was completed successfully in only 19 hours (5 hours ahead of schedule) with zero accidents, injuries and disruptions to the refinery’s ongoing operations.

 "The cleaning project safely converted an existing fuel gas piping system into an instrument air piping system, eliminating the need to build a new, and very expensive, air pipeline."
- Gary Oberbroeckling, Product Development Manager, Veolia North America