CPC F16L 55/46 (2013.01) [B08B 9/0535 (2013.01); B08B 9/055 (2013.01); B08B 2209/045 (2013.01); B08B 2209/055 (2013.01); F16L 55/30 (2013.01); F16L 2101/12 (2013.01)] | 9 Claims |
1. An intervention drive pig comprising an umbilical comprising a first material of low density and wherein the umbilical comprises an external covering of a second material of low coefficient of friction, wherein the second material comprises polyvinylidene fluoride (PVDF) or molybdenum disulphide.
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