Manhole riser having integral flexible waterlock for manhole covers and having a water tight seal for sealed manhole covers

摘要

A hollow, flexible, bendable, cylindrical-shaped, hat-like sleeve is water-tightly joined with the upper end of the riser section of a manhole structure. The free end of the sleeve is trimmed so that its upper edge fits beneath the shoulder of the frame supporting the manhole cover to prevent subsurface water from entering into the manhole interior through the regions between the manhole cover supporting frame and the top of the riser section, which is usually fitted with adjustment rings to bring the manhole cover frame up to grade. The sleeve is easily cut to any height to accommodate either a greater or lesser number of height adjustment rings. The sleeve flange is cast into the riser section. The sleeve may be folded into itself to significantly lower its profile to expedite handling, transportation and assembly. A plastic clamping band may be placed into the interior of the sleeve to water-tightly join the upper end of the sleeve to the manhole cover support frame.