The design philosophy of pipeline cleaning using bi-directional [bidi] disc pigs, also known as scrapers or mandrel pigs, lies behind the need to pig in both directions. The design of bi-directional [bidi] relies upon support or guide discs typically 1% or 2% less than that of the internal diameter [ID] of the pipeline and sealing discs, which are larger than the internal diameter [ID] termed “interference”.
Standard bi-directional pigs [bidi pigs] include four sealing discs, which are used for high performance sealing as well as drive discs together with two support discs in two packages to ensure equal support. This design provides the most stable performance to assist in the removal of light deposits from pipe walls. This can be further enhanced in terms of cleaning ability by the addition of brushes.
iNPIPE PRODUCTS™ bi-directional pigs can also incorporate extended sealing/pig body lengths to overcome extended sealing requirements due to extended lateral features such as wye junctions, subsea connection features or various combinations of tee connections, including sphere and barred tee options.
Benefits of Bi-Directional or Bidi Pigs
- Stable and centralised operation
- High performance sealing
- Can travel in either direction within the pipeline
- Polylast AAA abrasive resistant systems mean that these pigs can withstand up to 1,000km distances
- Can be designed to accommodate multi diameter pipelines
- Successful design for removing light deposits from the pipe wall
- High strength neodymium magnetic cleaning for removal of ferrous debris
- Radial and spring mounted brush options
- Spring mounted plough blades for wax or scale removal
- Pipeline gauging and data logging options
- Articulated dual module bi-di options to traverse all pipeline features
- Check valve design options
- Spring mounted support wheels
- Magnetic, acoustic, electro-magnetic and radioactive source tracking options