Plastic liner sections define a drainage channel when placed end to end.
Each end has a stiff, double walled flange at each side of the end
adapted to butt up to a similar flange at the adjacent end of the next
sections. The double walled construction of the flanges stiffens the ends
significantly reducing the risk of deformation by the hydrostatic forces
produced by wet concrete during installation. A groove is formed inwardly
of the flanges on a female end of the liner section and receives a
sealing ring, which is held in place by a lip formed on a male end.