External pipe coatings for a reinforced pipe
AssigneeBritish Gas Corporation
InventorDavid Gray
Life of this patent
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Abstract
Metal pipes are protected from corrosion by externally coating the pipe with a layer of coal tar and wrapping the pipe with at least one extensible material which is porous to allow the coal tar to pass through to form a layer on the outside. This type of wrap avoids any cracking of the protective materials during the commissioning and operation of the pipe.
Claims6
In a metal pipe for the transmission of a fluid under pressure, the exterior of said metal pipe being coated with a reinforced protective layer comprising coal tar for corrosion protection reinforced with a layer of reinforcement fiber, the improvement wherein resistance to cracking and failure of the protective layer due to strain on the metal pipe are increased by utilizing, as the reinforcement fiber, a layer of longitudinally extensible porous synthetic organic polymer tissue and a layer of longitudinally extensible glass based fabric, both of said layers of reinforcement fiber being wrapped around the pipe in contact with said coal tar layer whereby the coal tar passes freely through to form a second layer of coal tar on the outside of said organic polymer tissue.
Dependencies are inferred from the claim text.