Strip for helically winding to form pipe

摘要

The strip comprises a narrow flat body with a joining rib at one edge perpendicular to the str p and longitudinally continuous, and a socket at the other edge to receive the rib. A second rib slants outwardly from the lower part of the socket, and soft elastic packing is located between the connection between socket and second rib and body and first rib so that it is compressed when strip turns are joined. - There may be a reinforcing rib perpendicular to the strip body, longitudinally continuous and at a fixed distance from the first rib, so that when the first rib is inserted into the socket the second rib engages the reinforcing rib and is stopped by it. The strip is e.g. of PVC.