Pipe liner and associated methods

A method of manufacturing a liner, the method comprising:

• extruding an inner polymer pipe;
• surrounding the inner polymer pipe with a barrier layer;
• and
• surrounding the barrier layer with an outer polymer pipe;
• wherein the inner polymer pipe is porous, having a plurality of pores or interstices which permit the passage of gas, such that the inner polymer pipe permits free movement of gas between the internal bore and the barrier layer, preventing accumulation of gases within the layers of the liner;
• wherein the inner polymer pipe is bonded to the barrier layer using an adhesive;
• and
• wherein the outer polymer pipe is non-porous.

A composite pipe comprising:

• a first polymer pipe;
• a barrier layer surrounding the first polymer pipe;
• and
• a second polymer pipe surrounding the barrier layer;
• wherein the first polymer pipe is porous, having a plurality of pores or interstices which permit the passage of gas, such that the first polymer pipe permits free movement of gas between an internal bore and the barrier layer, preventing accumulation of gases within the layers of the composite;
• wherein the first polymer pipe is bonded to the barrier layer using an adhesive;
• and
• wherein the second polymer pipe is non-porous.

A method of manufacturing a composite pipe comprising:

• extruding an first polymer pipe;
• surrounding the first polymer pipe with a barrier layer;
• and
• extruding a second polymer pipe over the barrier layer;
• wherein the first polymer pipe is porous, having a plurality of pores or interstices which permit the passage of gas, such that the first polymer pipe permits free movement of gas between an internal bore and the barrier layer, preventing accumulation of gases within the layers of the composite pipe;
• wherein the first polymer pipe is bonded to the barrier layer using an adhesive;
• and
• wherein the second polymer pipe is non-porous.