ROCLA’S HDPE vertical cast pipes were specified for two phases of the Polokwane Wastewater Treatment Project, which ran from 2018 to the end of December 2020.
The project, which was subdivided into three phases, is based in the Seshego area in Polokwane. It was initiated to upgrade existing sewerage system, to meet the increased requirements of the Seshego local communities. Each phase of the project had a separate starting point with a common joining at a single point.
Rocla, Regional Sales Manager, Andrew Kruger said the project was commissioned by the Polokwane Municipality to upgrade a now outdated sewerage system which no longer met the local community’s requirements.
“We worked closely with site contractor Safcrete Construction so that the quality of the pipes would be to the standard required and delivery scheduling would be as seamless as possible,” Kruger said.
The pipes were 2.5m Silica Rolling Joint Pipe, comprising a 3mm sacrificial layer. Five sizes of pipe were required — 900mm, 1000mm, 1200mm, 1400mm and 1500mm – and, according to Kruger would stretch over 19km if placed end-to-end.
“The placement of each pipe required the insertion of a rubber ring and the welding of a ‘capping strip’ on the inside of each individual joint to ensure proper sealant.”
He said advantages of Rocla’s HDPE lining for water and sewer projects advantages included the fact that it is much smoother than concrete, enabling the use of smaller internal diameter piping. The long-term pullout strength of the lining anchors is able to cope with a ground water pressure in excess of 10m.
“In order for our Polokwane factory to manufacture the various sizes of pipes and the required quantities, Rocla Polokwane underwent an overhaul in terms of the manufacturing sections needed to accommodate the upgraded equipment.
“We also made use of special Vertical Cast (VC) moulds which were required for use with the insertion of the sacrificial layer within the pipes. It was these changes that enabled us to meet the quantities of HDPE pipes required for the Polokwane Wastewater Treatment Plant projects as they enabled us to increase our production schedules and deliver to site timeously,” Kruger said.
Rocla is part of the ISG which also includes Technicrete.