Rotork in water works upgrade

27 March 2008

Severn Trent has upped reliability, while cutting costs and maintenance, with 136 valve actuators, part of an £8 million pound modernisation programme in the Cheltenham and Worcester areas. Interserve Project Services, the Reading based building group that won the contract, specified Rotork IQ and IQT range intelligent electric valve actuators for use in the project.

A Rotork engineer locally operates a newly installed Rotork IQT actuator during commissioning

The actuators, installed by Rotork’s Bath based Site Services Division, were fitted to existing valves on Rapid Gravity (RGF) and Granulated Activated Carbon (GAC) filter beds. This is claimed to be a more reliable, economical and low maintenance alternative to the hydraulically operated system originally installed.

Nikki Holden, senior Interserve agent at the water treatment works, said: ‘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.’

She continued: ‘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 twenty GAC filter beds at the water treatment works has been retrofitted with Rotork IQ multi-turn actuators on 500 and 600mm inlet and outlet penstocks and IQT direct drive quarter-turn actuators on 200mm air scourer butterfly valves. Rotork Site Services’ scope of supply encompassed an initial valve survey, the design and manufacture of new screwed valve stems and pedestals for the penstocks and adapters for the butterfly valves, actuator sizing, installation and commissioning. Butterfly valve adapters were sourced from Valvekits, the Rotork Group’s dedicated valve accessory company.

The IQ/IQT actuators feature ‘non-intrusive’ commissioning and data interrogation by means of a bi-directional infrared 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.