| 摘要 |
PROBLEM TO BE SOLVED: To provide a synthetic resin flexible pipe stably securing flow passage cross-sectional area without narrowing a fluid flow passage at the inside by bending and crushing, although a flexible part by soft synthetic resin is provided in a part of the synthetic resin flexible pipe.SOLUTION: This flexible pipe is formed to a double-tube for piping by covering an outer periphery of an inner layer tube 11 having the fluid flow passage 12 at the inside and made of the soft synthetic resin having flexibility with an outer layer tube 13 made of rigid or semi-rigid synthetic resin. The outer layer tube 13 at a bent part of the double-tube is provided with a spiral cut line 21 for making the outer layer tube 13 flexible or many ring-shaped or partially ring-shaped cut lines. |
