Gas riser apparatus and method

A method of assembling a metal-to-plastic transition assembly, the assembly comprising a pipe fitting, adaptor sleeve, tube, and stiffener, the method comprising the steps of:

• inserting a first end of the adaptor sleeve into the pipe fitting;
• securing the fitting to the adaptor sleeve;
• inserting the stiffener into a first end of the tube;
• advancing the first end of the tube and stiffener into a second end of the adaptor sleeve until the stiffener and said first end of the tube are adjacent securing means on an inner surface of the adaptor sleeve;
• and,
• passing a mandrel through the tube, past the first end of the tube, past the stiffener and adaptor sleeve, and past the pipe fitting, thereby outwardly deforming the insert and urging the tube into sealing engagement with the securing means on the inner surface of the adaptor sleeve.

An assembled metal-to-plastic transition joint comprising:

• a metal pipe fitting;
• an adaptor sleeve having a first end and a second end and an adaptor sleeve flange therebetween, the adaptor sleeve having grooves in an inner surface thereof, and an internal stop surface, the first end of the adaptor sleeve received within the pipe fitting, the pipe fitting being welded to the adaptor sleeve flange;
• and,
• a plastic tube having a first end abutting the internal stop surface, and outer surface of said tube near said first end deformed into engagement with the grooves.

A method of assembling a gas riser having a pipe nipple, outer casing, adaptor sleeve, and tube, said method comprising the steps of:

• inserting a first end of the adaptor sleeve into the pipe nipple;
• inserting a second end of the adaptor sleeve into a first end of the outer casing;
• securing the pipe nipple and the first end of the casing to the adaptor sleeve;
• subsequently advancing a first end of the tube into a second end of the outer casing until the tube first end is adjacent securing means on an inner surface of the adaptor sleeve;
• and,
• deforming said tub into sealing engagement with the securing means of the adaptor sleeve.

A method of assembling a gas riser having a pipe nipple, casing, adaptor sleeve, tube, and stiffener, said method comprising the steps of:

• inserting a first end of said adaptor sleeve into a second end of the pipe nipple;
• inserting a second end of said adaptor sleeve into a first end of the casing;
• securing the pipe nipple and the first end of the casing to the adaptor sleeve;
• inserting the stiffener into a first end of the tube;
• advancing the first end of the tube into a second end of the casing until the stiffener and tube first end are adjacent securing means on an inner surface of the adaptor sleeve;
• and,
• passing a mandrel through the tube, past the stiffener and adaptor sleeve, and out a first end of the pipe nipple, thereby outwardly deforming the insert and deforming the tube into sealing engagement with the securing means of the adaptor sleeve.

A method of assembling a gas riser having a tube and a metal pipe, the metal pipe having first and second ends and grooves on an inner surface thereof, said method comprising the steps of:

• passing a first end of an associated rod through the pipe;
• passing the rod first end through an annular insert;
• passing the rod first end through the tube;
• attaching a mandrel to the rod, an outside diameter of the mandrel being greater than an inside diameter of the annular insert;
• inserting a second end of the annular insert into a first end of the tube;
• pushing the tube first end into the pipe first end until the annular insert and the tube first end are positioned adjacent the grooves on the inner surface of the pipe;
• and,
• passing the mandrel through the tube, out of the tube first end, and out of the pipe second end, thereby outwardly deforming the annular insert and the tube first end into sealing arrangement with the grooves on the inner surface of the pipe.

An assembled plastic-to-metal transition joint for use in gas risers, said joint comprising:

• a metal pipe fitting;
• a metal casing;
• an adaptor sleeve having first and second ends and a set of grooves defined in an inner surface thereof, the first end of the adaptor sleeve being received within the metal pipe fitting and the second end of the adaptor sleeve being received within a first end of the casing, the pipe fitting and the casing first end being welded to said adaptor sleeve;
• and,
• a plastic tube generally coaxially disposed within the casing, an outer surface of the tube near the first end being deformed into locking engagement with the grooves, the engagement preventing axial movement of the tube within the casing.

A gas riser comprising:

• a pipe nipple;
• an adaptor sleeve having first and second ends, the first end being received within the pipe fitting;
• and means attaching said first end to said pipe nipple;
• a casing having a first end receiving the second end of the adaptor sleeve;
• and means attaching said second end to said casing,
• a tube having a first end received within and sealingly engaging the adaptor sleeve by deformation of a portion of the tube into at least one groove in the adaptor sleeve.

A gas riser comprising:

• a pipe nipple having first and second ends, the first end being threaded for engagement with an associated gas meter manifold;
• an adaptor sleeve having first and second ends interconnected by an inner wall extending through the adaptor sleeve, and a series of grooves defined on the inner wall, the first end of the adaptor sleeve being received within the second end of the pipe nipple and means attaching said first end to said second end of said pipe nipple;
• a casing having first and second ends, the first end of the casing receiving-the second end of the adaptor sleeve and means attaching said first end of said casing to said second end of said adaptor sleeve;
• a tube having first and second ends, the first end of the tube being received within the casing and the adaptor sleeve, the second end of the tube extending beyond the second end of the casing and adapted for attachment to an associated pipe;
• and,
• a stiffener received within the first end of the tube, the stiffener being plastically deformable outwardly against the interior surface of the tube, thereby plastically deforming the first end of the tube into sealing engagement with the grooves on the inner surface of the adaptor sleeve.