Wessex Water - Pipeline Cleaning and Descaling Sections of Critical Pipework

Wessex Water provides water and sewerage services to an area of south west England. It is responsible for providing water to Bath, Dorset, parts of Somerset and Wiltshire. As such it has multiple sites situated in the south west including 200 water sources and water treatment works, 200 pumping stations, 340 service reservoirs and more than 11,000 km of water mains.

The work involved descaling sections of critical pipework. Wessex Water removed a heavily scaled mixer tube with baffles and lifted it to an adjacent lay down area ready for descaling. This gave access to the inlet pipework which was also heavily scaled up.

RGL started with descaling the inlet pipe while insitu and undertook this work using a high pressure diesel powered jetting unit and rotating pipe cleaning head.

The jetting unit ran at a pressure of 600bar providing a flow of up to 30 litres of water per minute. The head was fitted with two 90 degree jets and two 45 degree rear facing jets. It was thus able to pull itself up the pipe whilst cutting the scale and flushing the removed debris simultaneously.

A lower pressure was selected on the mixer tube with baffles as the lining of the pipe had to be left intact. By using the safety lance the jet itself was closer to this lining than in the previous operation completed with the pipe cleaning nozzle. The descaling work was completed within 4 hours of RGL’s arrival in site, providing adequate time for the mixer baffle to be reinstalled to the clean waterline and for the plant to resume functionality before the closure of another site was implemented.