Pipe Coating Process (Patent No: 733462)

Inventor: Boyce, James J.

Location: Edmonton

Comments: N/A

Description:

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method of coating elongated metal goods with a resin which comprises the steps of heating at least the surface to be coated to a temperature above the melting point of the resin, coupling said heated metal goods together in axial alignment, horizontally passing said coupled metal goods axially through a coating zone, applying the resin in a dispersed particulate form in the coating zone to the heated surface of the metal goods such that said resin will adhere, melt and coalesce on the surface to form a continuous layer, and cantilevering said coupled goods through a cooling zone for cooling said coated surface to a temperature below the melting point of the resin to convert the liquid resin coating into an impermeable and continuous coat bonded to said surface.

2. A method of providing a corrosion resistant coat of a synthetic resin to metal rod, pipe and tubular goods which comprises the steps of cleaning the surface to be coated, heating at least the surface to be coated to a temperature above the melting temperature of the synthetic resin, coupling said heated metal goods together in axial alignment, passing said coupled metal goods axially through a coating zone, impelling the resin in a dispersed particulate form in the coating zone on to the heated surface of the metal goods such that the resin will adhere to the surface, melt and coalesce to form a continuous coating, and cooling the coated surface to a temperature below the melting temperature of the resin to convert the liquid resin coating into an impermeable coat and effect bonding of said coat to said surface, said coupled metal goods being cantilevered for unsupported horizontal travel through the coating and cooling zones.
















3. A method for continuously coating elongated metal goods with a corrosion resistant synthetic resin which comprises the steps of blasting the surface to be cleaned with an abrasive for liberating impurities attached to said surface, washing said surface with a fluid to remove said liberated impurities, heating said surface to a temperature above the melting point of said resin, coupling said heated metal goods together in axial alignment, passing said coupled metal goods axially through a coating zone and a cooling zone by cantilevering said goods for unsupported horizontal travel, applying said resin in a dispersed discrete form with a gaseous medium to the heated surface to be coated in the coating zone such that said resin adheres, melts and coalesces on said surface, and cooling said coated surface to a temperature below the melting point of said resin in the cooling zone by quenching said surface with a coolant converting said resin coating into an impervious, continuous skin securely bonded to said surface.




4. A method of coating the exterior of pipes with a synthetic resin which comprises the steps of blasting the exterior surface of the pipes with an abrasive material to provide a primary cleaning of said surface and washing said surface with an acid to provide a secondary cleaning of said surface, heating at least the surface of said pipes to a temperature in the range from about 400°F. to about 600°F., coupling said heated pipes together in axial alignment, passing said coupled pipes axially through a coating zone and a cooling zone contiguous to said coating zone by cantilevering said goods for unsupported horizontal travel, applying the synthetic resin in a discrete dispersed form carried by a gaseous medium to the pipe surface in the coating zone such that the resin adheres, melts and coalesces on said surface to form a continuous coating or a thickness at least about 10 thousandths or an inch and cooling said coated pipes by spraying the pipes with a coolant to convert the resin coating into an impermeable continuous coat integrally bonded to the pipe surface.
5. A method or coating the exterior or metal tubular goods and rods with an epoxy resin which comprises the steps of blasting the exterior surface or the tubular goods and rods with an abrasive material for liberating impurities attached to said surface, removing said impurities from the said surface, heating said surface to a temperature about 415°F. to about 430°F., coupling said heated tubular goods and rods together in axial alignment, passing said coupled tubular goods and rods axially through a coating zone and a contiguous cooling zone by cantilevering said goods for horizontal unsupported travel, applying said resin in a particulate form dispersed in a gaseous medium to the heated surface to form a continuous resin coating having a thickness or about 10 thousandths of an inch and cooling said surface to normal temperature by spraying said pipe with a coolant to convert said resin coat into an impervious, continuous skin integrally bonded to said surface.

6. A method of coating the exterior of elongated metal goods with a polyester resin which comprises the steps of blasting the exterior surface of the goods with an abrasive material for liberating impurities attached to said surface, removing said impurities from the surface, heating said pipe to a temperature about 600°F., coupling said heated metal goods together in axial alignment, passing said coupled metal goods axially through a coating zone and a contiguous cooling zone by cantilevering said goods for horizontal unsupported travel, applying said resin in a particulate form dispersed in a gaseous medium to the heated surface in the coating zone to form a continuous resin coating having a thickness of about 10 to 12 thousandths of an inch, and cooling said goods to normal temperature by spraying said surface with a coolant to convert said resin coat into an impervious, continuous skin integrally bonded to said goods.

7. A method of coating the exterior of elongated metal goods with a polyethylene resin which comprises the steps of blasting the exterior surface of the pipe with abrasive material for liberating impurities attached to said surface, removing said impurities from the surface, heating said surface to a temperature about 400°F., coupling said heated metal goods together in axial alignment, passing said coupled metal goods axially through a coating zone and a contiguous cooling zone by cantilevering said goods for horizontal unsupported travel, applying said resin in a particulate form dispersed in a gaseous medium in the coating zone to the heated surface to form a continuous resin coating having a thickness of about 30 thousandths of an inch, and cooling said surface to normal temperature by spraying said surface with a coolant to convert said resin coat into an impervious, continuous skin integrally bonded to said surface.


8.


A method of coating the exterior of elongated metal goods with a synthetic resin which comprises the steps of blasting the exterior surface of the goods with an abrasive material to scour impurities from the surface, washing said surface with an acid and water to clean said surface, heating said surface in a primary heater to about 250°F. and heating said surface in a secondary heater to a temperature between the range from about 400°F. to about 600°F., coupling said heated metal goods together in axial alignment, passing said coupled metal goods axially through a coating zone and a contiguous cooling zone by cantilevering said goods for horizontal unsupported travel, spraying said heated surface with the solid resin in a particulate dispersed form in the size range of from 6 to 300 microns in the coating zone such that the resin particles adhere, melt and coalesce on said surface to form a liquid coat having a thickness of at least about 10 thousandths of an inch, and cooling said liquid resin coat by passing said coated goods first through cooling air and second through a spray of coolant to convert the sprayed resin coat into an impermeable and corrosion resistant coat integrally bonded to the exterior surface of the goods.


9. An apparatus of the type used for continuously coating the exterior of a plurality of elongated metal goods with a resin which comprises, in combination, means for blasting the surface of said goods with an abrasive material to effect a primary cleaning, means for washing said abraded surface to effect a secondary cleaning, furnace means for heating at least the surface or said goods to a temperature above the melting point or said resin, coupling means for connecting said goods for unsupported horizontal travel, coating means for spraying the resin in a discrete dispersed form onto the exterior surface or said goods such that said resin adheres, melts and coalesces on said surface to form a continuous coating, and means for cooling said coated goods consisting or cantilevering means for passing said goods through unsupported travel in an air gap in a spray or coolant in a quenching tunnel.


10. An apparatus for continuously coating the exterior of elongated metal goods with a resin which comprises, in combination, means for abrading the surface of said goods to effect a primary cleaning, means for washing said abraded surface to effect a secondary cleaning, furnace means for heating at least the surface of said goods to a temperature above the melting point of said resin, coupling means for connecting said goods and cantilevering means for horizontally advancing said goods axially through a span for unsupported travel, coating means at the commencement of unsupported horizontal travel for spraying the resin in a discrete dispersed form onto the exterior surface of said goods such that said resin adheres, melts and coalesces on said surface to form a continuous coating and cooling means consisting of a spray of coolant in a quenching tunnel at the opposite end of the span for cooling said coating.


11. In an apparatus as claimed in claims 9 or 10, said means for cantilevering said coupled metal goods comprising at least one pair of rollers adapted to receive the metal goods therebetween, said rollers being spaced apart relative to the axis of the goods.