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US 5,992,897 AGranted
Joining lined pipe items
AssigneeBG plc
InventorsTom Hill, Robert James Cummings
Life of this patent
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AssigneeBG plc
InventorsTom Hill, Robert James Cummings
Estimating the term…
Steel pipe items such as pipes (10) are each joined by a girth weld (14) to tubular steel fittings (12) and the pipes (10) are each lined by pulling a polyethylene liner (30) through the pipe (10) and through the fitting (12). A ring (32) is forced into each fitting (12) to compress the liner (30) and force it into grooves (20) in the internal surface of the fitting (12). The grooves (20) are separated by castellations (22). The grooves (20) are in a corrosion-resistant cladding (18) deposited on the interior of each fitting (12). Alternatively, the whole of each fitting (12) is made of corrosion-resistant Duplex steel. The ends of the liners (30) are cut short of the ends of the fittings (12) and an annulus 940) of liner material is inserted in the gap. The annulus (40) has an external groove (42) accommodating a body (44) of heat insulation material. The ends of the fitting (12) are joined by a girth weld (15).
A method of joining two pipe items comprising joining to an end of each item a tubular metal fitting, each fitting having a free end and having an internal surface formed of corrosion resistant metal which extends to the free end of the fitting, said internal surface of said fitting having grooves separated by castellations, lining each of the pipe items and at least a portion of the fitting joined thereto with a thermoplastic liner, forcing a respective ring of corrosion resistant metal into the liner in each fitting to compress the liner and force it into the grooves of each fitting, and joining the fittings.
A method of joining two pipe items comprising joining to an end of each item a tubular metal fitting, each fitting having a free end and having an internal surface formed of corrosion resistant metal which extends to the free end of the fitting, said internal surface of said fitting having grooves separated by castellations, lining each of the pipe items and at least a portion of the fitting joined thereto with a thermoplastic liner, positioning a respective undersize ring of corrosion resistant metal in the liner in each fitting, and forcing the undersize ring outwardly to compress the liner and force it into the grooves of each fitting, and joining the fittings.
A method of joining two pipe items comprising joining to an end of each item a tubular metal fitting, each fitting having a free end, an external flange at said free end, and having an internal surface formed of corrosion resistant metal which extends to the free end of the fitting, said internal surface of said fitting having grooves separated by castellations, lining each of the pipe items and at least a portion of the fitting joined thereto with a thermoplastic liner, forcing a respective ring of corrosion resistant metal into the liner in each fitting to compress the liner and force it into the grooves of the fitting, and joining the fittings by bolting through the flanges.
A method of joining two pipe items comprising joining to an end of a first pipe item a tubular metal fitting, said fitting having a free end, an external flange at said free end, and having an internal surface formed of corrosion resistant metal which extends to the free end of the fitting, said internal surface of said fitting having grooves separated by castellations, lining the first pipe item and at least a portion of said fitting joined thereto with a thermoplastic liner, forcing a respective ring of corrosion resistant metal into the liner in said first fitting to compress the liner and force it into the grooves of the fitting and joining the fitting to a second pipe item made of corrosion resistant metal and having an external flange by bolting through the external flange of said fitting and the flange of said second pipe item, said second pipe item not having a linear or a ring.
Dependencies are inferred from the claim text.