A drainage sealing device for sealing a drainage opening at the lower end of a manhole shaft

摘要

A seal base unit 42 for a manhole shaft 2 comprises first and second sections 46a and 46b which together form a side flange for abutting a side wall 49 of the manhole shaft 2 and a support flange 48 for supporting a closure 44. The closure 44 may comprise a drainage sealing device, the device comprising first and second elements 22, 24 each having a first edge. The first and second elements 22,24 are pivotally connected about their respective first edges 25 for movement between a first position in which the first and second elements 22, 24 are aligned, and a second position in which the first and second elements 22, 24 are no longer aligned and the first and second elements 22, 24 may be placed in position or removed from the drainage opening (see Figs 3A, 3B and 3C).