Method and apparatus for porting lateral connections in lined pipelines

A method of cutting an opening in a liner installed in a conduit at a location where the liner covers openings in the conduit where a lateral pipe is coupled to the conduit, comprising:

• cutting a first hole in the liner at the region covering the lateral opening;
• inserting cutting means including water cutter means for cutting the liner with a jet of fluid through the hole to the lateral side of the liner with the water cutter means facing towards the liner;
• urging the cutting means against the inside surface of the lateral pipe;
• advancing the cutting head along the inside surface of the lateral pipe and using the inside surface as a guide;
• cutting a lateral opening through the liner corresponding to the original shape of the opening in the conduit from the lateral side of the liner by projecting a jet of fluid at the liner from the water jet cutter.

An apparatus for cutting lateral opening in an installed conduit having a liner therein covering the lateral openings in the conduit for connecting the conduit to the laterals, comprising:

• location and positioning means for locating the side openings in the conduit;
• drill means for cutting a hole in the liner;
• insertion means for inserting a cutting device from the conduit through the hole in the liner to the lateral side of the liner;
• and
• cutting means including water cutter means for cutting the liner with a stream of fluid adapted to face toward the outside of the liner for advancing along the inside surface of the lateral pipe and cutting the liner in the shape of the opening in the conduit from the lateral side of the liner as the cutting means advances.

A method for cutting an opening in a liner installed in a conduit at a location where the liner covers openings in the conduit where a lateral pipe is coupled to the conduit, comprising:

• feeding water cutter means for cutting through the liner through a lateral pipe towards the covered opening;
• urging the water cutter means against the inside wall of the lateral pipe;
• and
• displacing the water cutter means around the inside wall of the lateral pipe while cutting through the liner from the lateral pipe side of the liner by use of a stream of fluid from the water cutter means and forming an opening in the liner that is the same shape as the connection of the lateral pipe and the conduit.

An apparatus for forming an opening in a liner of a conduit to make a lateral connection at the location where the installed liner covers side openings in the conduit to lateral pipes, comprising:

• a first arm and a second arm having two ends with a first end pivotally connected to the first arm;
• cutting means for cutting through the liner pivotally connected to the second end of the second arm;
• separation means for urging the first arm apart from the second arm and for urging the cutting means apart from second arm so that the cutting means is pressed against an inner wall of the lateral;
• advancing means for displacing the cutting means around the inside surface of the lateral pipe to cut the liner to the shape of the side opening in the conduit.

A method of forming an opening in a liner installed in a conduit at a location where the liner covers an opening in the conduit where a lateral pipe is coupled to the conduit, comprising:

• forming a first hole in the liner at the region covering the lateral opening;
• inserting a cutting device through the first hole, the cutting device at the end of a jointed member which doubles back towards the liner after insertion through the first hole;
• urging the cutting device against the inside surface of the lateral pipe by spreading apart the jointed member;
• advancing the cutting device along the inside surface of the lateral pipe and using the inside surface as a cutting guide and forming a lateral opening through the liner corresponding to the original shape of the opening in the conduit, from the lateral side of the liner.