Retrofit increases valve efficiency at Dutch water treatment plant

Amsterdam – Waternet has installed Rotork modulating electric valve actuators as part of an efficiency upgrade project at a large water treatment works serving Amsterdam.

The Waternet facility at Vogelenzang has a daily water treatment capacity of 180,000 cubic metres, using a regime comprising pre-screening, carbon filtration, ozone injection and sand filtration.

Waternet covers the entire water cycle, from the treatment of waste water and provision of drinking water to cleaning and maintaining levels of surface water. These services are performed on behalf of the Regional Public Water Authority - Amstel, Gooi and Vecht - and the City of Amsterdam.

Reliability problems had arisen with the electric actuators on the carbon filtration plant at Vogelenzang, which were failing to cope with the modulating valve duties required for efficient filtering and backwashing operations.

Rotork’s solution was to remove the old actuators, install IQTMPro quarter-turn modulating actuators directly onto the affected butterfly valves and connect to the existing power and control cabling. This work was performed by Rotork Site Services, the company’s division for retrofitting, site maintenance and repair activities.

The site wiring interface with the old actuators was by means of plug-and-socket connections. In order to retain these, Rotork engineered a separate plug-and-socket housing, locally sited by each new actuator and connected to the actuator terminal compartment. This, said Rotork, has speeded up installation and enabled the new actuators to be retrofitted with minimal modification to site wiring.

On completion of the project, a total of 120 IQTM1000 actuators had been installed on DN350 and DN400 butterfly valves.

Rotork has also been awarded a ten-year maintenance contract for the actuators, involving tri-annual inspections and functional testing.