Capespan Namibia – NGC Bulk Water Supply Pipeline
New Bulk Water Supply Pipeline and River Abstraction Pump Station
The Project consisted of a new 800mm Diameter GRP Pipeline of 6km long with an elevation change of 132m. The design flow is 2800m³/h and is supplied by 4 x 450kW horizontal split casing centrifugal pump sets driven by Variable Speed Drives.
The challenge was to design for varying river levels. To achieve this the pumps were installed on trolleys that move up and down the river and connect to fixed T-pieces in a pipe installed in the stabilized and protected river bank.
During the flooding and for servicing the pumps, the trolleys can be moved all the way to the top to the overhead gantry. The Transient Surge Analysis was done in house and the Surge was reduced by installing a non-return valve and bypass two thirds along the line.