What are hydrocarbon resistant cables?

Hydrocarbons are organic compounds that are made of hydrogen and carbon atoms. They are notably found in crude oil and natural gas.

Hydrocarbons are either aliphatic or aromatic types, the difference between them is associated with the chemical bonding, with the two types reacting very differently.

Oil can be particularly damaging to cables. Two different processes can take place, either the plasticiser may migrate from the cable sheathing into the oil causing embrittlement and cracks in the cable sheathing. Alternatively, the oil may be absorbed by the cable sheathing and insulation materials causing swelling and softening of the material effecting their mechanical and electrical properties.

Hydrocarbon resistant cables, also referred to as MUD resistant cables, are particularly used in the marine industry where cables are manufactured to NEK606 standard, and oil and gas industry where they have traditionally been made with a lead sheathing layer such as the Type 3 BS5308 cables or the French standard NF M87 202 cables. The sheathing material serves as a barrier to moisture ingress and is resistant to hydrocarbons and many other chemicals. It should be noted that, where used, lead has many disadvantages, including environmental concerns, weight, cost and the requirement for large bending radii.