| 摘要 |
<p>PURPOSE:To make a drawing-in length longer by improving a property of tensile strength in a flexible pipe available at a time when a power cable or the like is laid under the ground in particular. CONSTITUTION:In a flexible pipe formed with a waveform in the axial direction of a pipe outer circumference, a rodlike tension member 12 with one or plural pieces of waveforms in the longitudinal direction is installed at both inner and outer sides of a waved pipe 10 so as to be projected in a finny manner.</p> |
