Rotork, with many global locations, including a number throughout the Americas, has assisted in meeting safety requirements on a Swedish bridge, by supplying GP, RCG and RC200 scotch-yoke actuators and control panels.
The Sundsvall Bridge in northern Sweden carries two 400 mm diameter district heating pipelines which are now protected by an emergency shut-off system incorporating Rotork pneumatic actuators. The spring-return heavy-duty GP actuators are fitted to DN400 ball valves installed on the main pipelines at each end of the bridge. In an emergency these actuators will shut the valves in one second.
To reduce the strain on the main lines when this occurs, bypass lines are fitted around the main pipeline ball valves. Valves on the bypass lines are fitted with RC260 compact double-acting actuators. Speed restrictors on these actuators increase their valve closing times to 40 seconds, minimizing the risk of excessive water-hammer in the pipeline system during an emergency shut-off.