In this post I want to share several examples of fail-safe position selection of control valves. I posted about this topic a long time ago. You can also check the post.
A control valve consists of valve body, trim, or stem, plug and seat, and an actuator. The valve body consists of an orifice through which the manipulated variable passes. The trim or stem is connected to the diaphragm and the valve plug that can be in the form of a ball, a disk, or a gate. The valve seat offers a tight seal for a valve shutoff position.
