Method of lining a pipe
OwnerFrederick Scragg, Peter Marshmaninventors
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Abstract
A method and apparatus for lining a pipe, e.g. an aluminium pipe, with a thermoplastic material, in which either the inner surface of the pipe or the external surface of a tube of thermoplastic material is coated with an adhesive layer, the tube is inserted in the pipe, a purely radial force is applied to press the plastic tube against the inner surface of the pipe, and axially progressive heating is applied to render the thermoplastic material into a plastic state.
Claims7
A method of lining a pipe comprising applying a nontacky adhesive layer to the inner surface of the pipe, the adhesive being capable of being heat activated at a first temperature value, to cause it to become tacky, inserting in the pipe a film of thermoplastic material to overlie the nontacky adhesive layer on the inner surface of the pipe, applying a uniform purely radial force to said thermoplastic material, while the adhesive is still nontacky, heating the assembly in an axially progressive manner, by affecting relative axial displacement between the pipe and a source of heat to raise the temperature to a value below said first temperature value to render the thermoplastic film to a plastic state and then heating the assembly at least to said first value to activate the adhesive and cause it to adhere to the thermoplastic film.
The method of lining a pipe comprising coating one surface of a film of thermoplastic material with a nontacky adhesive, which is capable of being activated at a first temperature value, to cause it to become tacky, forming the thermoplastic material into a tubular film with the nontacky adhesive on the exterior, inserting the tubular film into the pipe to be lined, applying a purely radial force to the thermoplastic material, while the adhesive is still nontacky, heating the assembly in an axially progressive manner, by affecting relative axial displacement between the pipe and the source of heat to raise the temperature to a value below said first temperature value to render the thermoplastic material into a plastic state and then heating the assembly at least to said first value to activate the adhesive and cause it to adhere to the thermoplastic film.
Dependencies are inferred from the claim text.