1. The following should be considered in the design of pipelines, based on the requirements for intelligent pigging:
2. The internal diameter variations of main line sections should be limited. This may require the heavy wall sections of the pipeline (e.g. risers, road or railway crossings) to be specified based on the internal diameter, instead of the outside diameter normally used.
3. Where sections of different internal diameter are connected together, the chamfer angle at the transition should not exceed 14 degrees, measured from the axis of the pipe (i.e. a taper of 1:4).
4. The main line valves should be full bore, i.e. same internal diameter as the pipeline.
5. All main line bends should have a sufficient radius to allow passage of intelligent pigs.
6. Most intelligent pigs are able to pass 3-D bends for DN400 and above, 5-D bends for sizes between DN250 and DN400. For pipe sizes below DN250, the required bends depend on the pipe internal bore (7-D to 10-D). This is only indicative.
7. The Manufacturers/Suppliers of intelligent pigs should be contacted during the design stage, to ensure that the geometry of the pipeline, including the pig launcher and receiver, is adequate.
