摘要 |
<p>PURPOSE:To prevent the change of the propulsion direction by providing many protruded stripes protruded outward from a pipe main body and extended in the axial direction at an interval in the peripheral direction on a collar coupled on the outside of the coupling section of a buried pipe. CONSTITUTION:Many protruded stripes 22 protruded outward and continuously extended in the axial direction are arranged at an interval in the peripheral direction on the outer periphery of a cylindrical main body section 21 made of synthetic resin to form a collar 20. Coupling sections 11 at the tips of mating buried pipes 10 are butted against each other, and the collar 20 is coupled on the outside of the coupling sections.</p> |