Material Selection and Working Principle of Pipeline Pigs

Pipeline pigs are specialized projectiles used in pigging systems to evacuate or recover residual media inside pipelines. Their working principle involves inserting an elastic sphere or cylinder (slightly larger than the pipeline’s inner diameter) into the pipe and propelling it using compressed gas or liquid (e.g., cleaning fluid). As the pig moves through the pipeline, it effectively removes residual media, ensuring cleanliness and smooth flow.

Material Selection

Pigs are typically made of rubber, polyurethane, or other elastic materials, available in various shapes such as spherical or cylindrical. Different materials offer distinct performance characteristics:

• Modified Polyurethane: Offers excellent flexibility and wear resistance, suitable for long-term operation.
• Fluorubber (FKM): Provides superior corrosion resistance along with high wear resistance, though at a higher cost.
• EPDM Rubber: More cost-effective but with slightly lower wear resistance compared to the above options.

The choice of pig material depends primarily on the composition of the pipeline’s transported media. For highly corrosive media, fluoroelastomer (FKM) pigs are preferred, while EPDM rubber pigs are a cost-efficient solution for less corrosive environments.

Working Principle

During pigging operations, the pig is propelled by fluid pressure, moving through the pipeline. Its slightly oversized diameter ensures tight contact with the pipe wall, effectively scraping off deposits, scale, or other contaminants. This design enhances cleaning efficiency, extends pipeline service life, and reduces maintenance costs.

By selecting the optimal pig material and refining its working mechanism, VP pigging systems deliver efficient and reliable pipeline cleaning solutions for various industrial applications.

JingSheng Gou

General Manager | Senior Technical Expert | Industrial Automation Specialist. Graduated from USTB, I served as an executive & technical expert at Beijing Shougang Electronics before becoming General Manager of BJVP Machinery in 1996. My expertise covers industrial automation and custom solutions including automated lubricant systems, pipeline pigging/launching, process control, precision weighing, and pump automation.