Rotork in valve actuation upgrade at Severn Trent site

London - Rotork has completed a major valve actuation upgrade at one of Severn Trent’s water treatment works. The project was part of an £8-million programme awarded to Interserve Project Services to upgrade the site, which serves the Cheltenham and Worcester areas.

Rotork’s Site Services Division fitted a total of 136 electric actuators to existing valves on rapid gravity (RGF) and granulated activated carbon (GAC) filter beds to provide a more reliable and low maintenance alternative to the hydraulically operated system originally installed.

“The actuators were specified for the upgrade application in line with the water industry’s preference for electric actuation, through Rotork’s framework agreement with Severn Trent," said Nikki Holden, Interserve senior agent at the water treatment works. "The choice of installer was the responsibility of Interserve as project manager and we selected Rotork Site Services for the work due to their specialist retrofitting skills and extensive experience of similar projects.”

Each of the 14 RGF and 20 GAC filter beds at the water treatment works has been retrofitted with Rotork IQ multi-turn actuators on 500 or 600mm inlet and outlet penstocks and IQT direct drive quarter-turn actuators on 200mm air scourer butterfly valves.

Rotork Site Services’ remit encompassed an initial valve survey, the design and manufacture of new screwed valve stems and pedestals for the penstocks and adaptors for the butterfly valves, actuator sizing, installation and commissioning. Butterfly valve adaptors were sourced from Valvekits, the Rotork Group’s dedicated valve accessory company.

Rotork IQ/IQT actuators feature ‘non-intrusive’ commissioning and data interrogation by means of a bi-directional infra-red link to a hand held setting tool. A data logger in each actuator stores historical valve operating data including torque profiles which can be downloaded and analysed using Rotork IQ-Insight software to minimise the requirement for routine valve maintenance.