External manhole chimney seal

摘要

A cylindrical elastomeric seal is disclosed for externally sealing a manhole assembly against surface water infiltration between the manhole casting and the supporting structure and through the supporting structure. The seal has a first sealing section adapted to receive the edge of the flange of a manhole casting, a second sealing section adapted to be received by the external surface of the manhole chimney or cone, and an intermediate section, joining the two sealing sections, that spans the vertical distance between the casting and the chimney or cone. Sealing means hold the two sealing sections in place against the casting and chimney or cone, creating watertight seals. An extension skirt increases the area the seal can cover, allowing the entire supporting structure to be sealed in the case where the chimney height is too great to be spanned by the intermediate section of the seal alone. The seal can be used on old or new construction and does not interfere with normal use of the manhole.