Marine growth retarding hose

#This invention relates to flexible hose and in particular, though not exclusively, to flexible hose suitable for the transportation of a corrosive fluid such as crude oil under high pressure.

#According to the present invention there is provided a flexible hose which comprises as its outermost layer a water-impermeable elastomeric composition having a thickness of at least 0.5 mm containing 0.1% to 10% by weight of particulate copper having a size equivalent to BS 100 mesh or smaller.

#By flexible is meant able to be bent to form an arc with a radius less than 20 times the diameter of the bore of the hose. Flexible hoses are easier to lay on the seabed from a barge and for some applications the hose will need to be flexed in use or bent through tight arcs to couple adjacent components of oil rig equipment. To be suitable for use in a flexible hose the elastomeric outermost layer must be suitably elastic. The copper dust-containing elastomer has an elongation at break of at least 200%, and exhibits virtually complete recovery from elongations of 100%. The elastomer should be chosen from a group which excludes those adversely affected by copper and its compounds, for instance, natural rubber is unsuitable, while modified ethylene-propylene, chlorinated polyethylene and chlorosulphonated polyethylene are suitable.

#One embodiment of the present invention will now be described, by way of example, with reference to the accompanying diagrammatic drawing which is a longitudinal cross-sectional view of part of a hose in accordance with the present invention.

#The hose comprises a liner assembly 11 including a polymeric material such as elastomeric polyacrylate disposed between a radially inner support layer 12 and a radially outer support assembly 13.

#The inner support layer 12 is formed from a single double folded helically wound strip 14 arranged with successive turns thereof in interlocked relationship.