Rotork, a manufacturer of electric, pneumatic and hydraulic valves and actuators, with branches in North and South America, recently received a large order for their high temperature specification Rotork RC200 scotch-yoke pneumatic actuators. The actuators will provide a vital fire safety duty in new subway tunnels under construction for the Istanbul Metro.
The Istanbul subway system in Turkey is undergoing a significant expansion program involving 900 km of new routes that are due for completion by 2023. Tunnels on the new routes are fitted with ventilation dampers in sizes up to 2 m2. To meet stringent safety standards, the actuators operating these dampers needed the ability to rapidly close them and shut the airflow in the event of a fire.
Rotork RC200 pneumatic actuators were selected for this application due to their compact design, fast operating capability, long-term reliability and minimum maintenance requirement. In addition, the actuators had to pass the stringent temperature and cycling tests required to meet the high level of safety demanded by the application. These included heating the actuator from -5ºC to +250ºC in only 20 seconds and then confirming reliable operation with no air leakage for a minimum period of one hour at the maximum temperature.