PURPOSE: To apply a lining to the inner surface of an existing pipe easily and in high reliability, by contracting the size of an impermeable tube having sef-restoring capability by applying external force, inserting the contracted tube into the pipe to be lined, and expanding the size of the tube by its own restoring force.
CONSTITUTION: A wire 6 is introduced into an existing pipe 1 having bends and changes in size through its opening by a fluid flow process. An impermeable tube A having self-restoring capability, and having a restored size of equal to or slightly larger than the inner size of the pipe 1, is inserted into a flexible sheath 7, and connected to the wire 6. The tube is introduced enteriely into the pipe 1, the contractive external force applied to the tube A is removed by taking out the sheath 7 from the pipe 1, thereby expanding the tube A by its own restoring force. By this method, an impermeable lining layer can be applied all over the inner surface of the pipe 1. The tube can be smoothly inserted into the pipe without abrasion and damage, and the restrictive conditions about the strength of the tube are reduced enabling the free selection of the material having most suitable physical properties
IMOTO NAMIO
NISHINO MASUSHI
