Where are door engine magnet valves located in a subway system?

The placement of door engine magnet valves in a subway system is critical for their operation. These valves are typically located above the doors. This positioning allows them to effectively control the opening and closing of the train doors. By being situated directly associated with the door mechanisms, the magnet valves can operate efficiently, ensuring that doors are secured during travel and only opened when appropriate, such as at stations for passenger boarding and alighting.

The other locations suggested would not serve the intended purpose. For instance, if the valves were under the seats, they would be too far from the door mechanisms to function properly and could lead to safety issues or delays. Similarly, a location near the control panel would not provide the necessary proximity to the doors for immediate responsiveness during operations. Finally, having the valves at the front of the train would also delay their operation concerning the door mechanisms, further complicating the process of managing door functionality.