| 摘要 |
An insert is provided for insertion through an opening in the surface of a conduit, the insert comprising an insert body having find and second open ends defining an axis of !low therebetween The insert further comprises a valve flap connected to the insert body. The valve clap is moveable between a closed position, in which it creates a closure, thereby preventing flow along said axis, and an open position in which the valve flap allows flow along the axis. The valve (lap is arranged so that, when in the open position, it is substantially U-shaped in side cross-section and is oriented with respect to the insert body so that said U-shape articles over the axis of flow. |
