How long does the valve open during the ignition sequence in a Direct Spark Ignition (DSI) system?

In a Direct Spark Ignition (DSI) system, the valve typically opens during the ignition sequence for a duration of 4 to 7 seconds. This time frame is crucial because it allows sufficient gas to flow to the burner, ensuring that there is enough fuel available to ignite when the spark occurs.

If the time were shorter, such as 2-5 seconds, it might not provide enough gas for a reliable ignition, potentially leading to unsuccessful lighting attempts. Similarly, if the time were extended to 8-10 seconds or beyond, it could increase the risk of gas accumulation, which poses a safety hazard. Hence, the 4-7 second window is optimized for both effective ignition and safety purposes in a DSI system.