A new service from USA DeBusk called Controlled-Volume Pigging™ (CVP) is rapidly becoming a preferred method for cleaning pipes, tubes and process equipment. The service is extremely safe and effective at removing the most challenging foulants. Better still, it has shown to be substantially faster than other cleaning techniques. This time-saving method not only reduces overall project costs, but can also mitigate safety risks by minimizing contractors’ time on-site and quickly restore processes that generate revenue for the plant.
The advantages of CVP were recently demonstrated in a major Gulf Coast petrochemical plant. The plant periodically experiences severe plugging in its recycle cooler. Previous cleaning techniques used by the plant took up to 12 hours or longer to complete. CVP successfully completed the project in under five hours.
Applications
CVP cleans carbon steel or stainless steel pipes and tubes as small as a 1/2 inch ID up to 8 inches ID in refinery, chemical plant and petrochemical plant equipment. It is effective in removing a broad range of foulants, including high-density polyethylene, low-density polyethylene, linear low-density polyethylene, wax, styrene, gumming materials, rust scale, tar materials, resid from Resid Hydrotreating Units and waste water sludges. CVP is an ideal alternative for applications where flex lancing is slow or ineffective.
Process
In pigging, special tools (pigs) are conveyed through a line to dislodge and push out fouling material. CVP uses water to propel the pig in a sealed system in which water volume, pressure and pig technology are precisely managed to achieve the desired cleaning results, all while protecting the pipe itself. CVP pigs can successfully navigate bends and 90-degree elbows, enabling the process to clean the entire 360-degree circumference for the full length of the line.
In CVP, water volumes can be relatively low (40 gpm) while operating pressures may be as high as 10,000 psi. Operating conditions are established in advance, with pressures never exceeding 60 percent of burst pressure for the pipe or tube. A regulator valve controls pressure throughout the process, and a rupture disc can be added to the system if desired.
Pig application is custom-engineered for each project, including the number of pigging cycles performed and the size, geometry, material and features of the pigs used throughout the project. A special water inlet nozzle creates a vortex and flushing effect that supplements cleaning during pig runs and when flushing material from the line. To complete the process, swabbing pigs are propelled through the line using plant air or nitrogen to completely dry interior surfaces.
Safe, effective and compact
CVP equipment is highly mobile, rigs up quickly and occupies a small footprint on the jobsite. Major components include a pump, pressure control system, pig launcher and receiver. Special valving controls flow and conserve water by recirculating it back to the pump when the system is not in use.
During cleaning, CVP crew members are not exposed to high-pressure water and are positioned away from the pig receiver where material is safely expelled. No chemicals are used; and the self-contained operation minimizes water requirements, making it environmentally friendly.
For more information, visit www.usadebusk.com or call (844) 243-5557.
