Solenoid valves are generally classified into two types: normally open type and normally closed type. The normally open solenoid valve means that when the coil is de-energized, the solenoid valve is opened; when the coil is energized, the solenoid valve is closed. A normally closed solenoid valve means that when the coil is de-energized, the solenoid valve is closed; when the coil is energized, the solenoid valve is opened.
We can choose the normally closed or normally open type according to the length of the continuous working time.
1. When the solenoid valve needs to be closed for a long time, and the closing time is longer than the opening time, and the continuous opening time is not very long, you can choose the normally closed type.
2. When it is necessary to open for a long time, and the opening time is longer than closing time. We recommend the normally open solenoid valve for you.
3. For gas alarm system, it is necessary to use the normally open type gas emergency cut-off solenoid valve with manual opening.
4. However, some conditions that need to be applied to safety protection, such as furnace and kiln fire monitoring, cannot be selected as normally open, and should be selected for long-term energization type.
If you are still confused about it, please contact us directly and we will recommend the best product for you.
Post time: Jul-28-2021