Controlled-Volume Pigging (CVP) is a highly effective pipe and tube cleaning method that outperforms flex lancing, hydro blasting and conventional pipe pigging.
It uses engineered cleaning pigs propelled by water with precisely controlled volumes, pressures and flow characteristics.
CVP removes gummy, sticky polymers and other tough foulants from the full circumference and length of a line.
The process is safe, efficient and requires only a fraction of the time of other cleaning methods.
CVP cleans and decontaminates pipes and tubes in a wide range of refinery, chemical and petrochemical plant applications.
It is effective with carbon steel or stainless steel pipes and tubes from ½ inches to 8 inches ID.
CVP removes the most challenging foulants, including:
- Gumming materials
- Rust scale
- Tar materials
- Resid from RHU units
- Waste water sludges
Safe, Environmentally Responsible
CVP is safe for crew members and does not harm customer equipment. A technician executes the process with remote controls from a position away from the inlet and opposite the exit point of flushed materials. Other crew members are stationed safely away from pressurized water and maintain clear communication with one another during the process.
No chemicals are used in the procedure. Pressures are carefully regulated to protect customer equipment.
The operation is self-contained to minimize water requirements, typically using approximately half the volume of water needed for ordinary hydro blasting.
System and Procedure
CVP uses a precisely regulated, low volume of water (40 gpm) and low pressures (≤10,000 psi) to convey engineered cleaning pigs through a pipe or tube to dislodge and push out fouling material.
A special water inlet nozzle creates a vortex that not only propels the pig but increases the cleaning and flushing action of the water.
CVP pigs successfully navigate bends and 90 degree elbows, enabling the process to clean the full circumference and length of the line. CVP can completely clean U-bundles in a single pass.
Pig application is custom-engineered for each project, including the number of pigging cycles performed and the size, geometry, material and features of pigs used throughout the project. To complete the process, swabbing pigs are propelled through the line using plant air or nitrogen to completely dry interior surfaces.
The CVP system is compact, highly mobile, rigs up quickly and occupies a small area on the job site.
Major components include a trailer-mounted pump, pressure control system, pig launcher and receiver.
Special valving controls fluid flow and conserves water by recirculating it back to the pump when the system is not in use.