Precast concrete manhole ring for sewerage - has bench invert and inset sleeves plus seal for connection incoming pipes

摘要

The precast concrete manhole ring (1) forms a benched invert (2) of the manhole. It may be deployed in sewerage works, and includes encastre pipe-coupling sleeves (3). A sleeve (3) is provided at each pipe inlet or outlet incorporated in the ring (1), is furnished with a compression seal (4), and accepts a spigot from the terminal pipe of ingoing or outgoing pipe runs. The sleeves (3) are set back inside the external barrel of the ring (1) and may be connected by a length of pipe (5) which is suitably shaped to benching requirements.