Self-acting control valve?

Relevant links on the forum: 1. http://bbs.hcbbs.com/viewthread.php?tid=96651&highlight=%D7%D4%C1%A6%CA%BD%B5%F7%BD%DA%B7%A7%B9%A4%D7%F7%D4%AD%C0%ED 2. http://bbs.hcbbs.com/viewthread.php?tid=399888&highlight=%D7%D4%C1%A6%CA%BD%B5%F7%BD%DA%B7%A7 3. http://bbs.hcbbs.com/viewthread.php?tid=398286&highlight=%D7%D4%C1%A6%CA%BD%B5%F7%BD%DA%B7%A7 There are many more; simply use the forum’s “search” function and search for “self-acting control valve””

Oh, the forum also allows searching. Thanks

Typical control valves use signals related to temperature, pressure, or flow rate to make adjustments based on the difference between the set value and the measured value. They generally include a signal amplifier and an actuator (usually pneumatic) to regulate the process parameters; in other words, they operate relying on external signals. A self-acting control valve, on the other hand, operates using its own signals; for example, signals from before or after the valve are directly applied to the self-acting valve to drive it. I wonder if the original poster understands what is being said?

Self-acting control valves utilize feedback signals from the valve’s output side (pressure, pressure difference, temperature), which are transmitted via signal tubes to the actuator in order to drive the valve disc and adjust the degree of opening of the valve, thereby achieving regulation of pressure, flow rate, and temperature. Such control valves are further divided into direct-acting and indirect-acting types. The direct-acting type is also known as the spring-loaded type; its structure includes elastic elements such as coil springs, bellows, and bellows-type temperature sensors. Self-acting control valves have distinct characteristics in that they utilize the energy of the medium itself to drive the actuator, which in turn operates the valve, thereby enabling regulation of parameters such as temperature, pressure, flow rate, and liquid level. Depending on the control object, they can be divided into self-acting pressure control valves, self-acting temperature control valves, self-acting flow control valves, and self-acting differential pressure control valves. Its advantages are energy conservation and environmental protection; it can achieve automatic control without the need for external energy, which helps companies save costs. With increasingly tight energy supplies today, it is bound to have an ever broader range of application prospects. Self-acting control valves have a very wide range of applications; they are used in industrial equipment in sectors such as petroleum, chemicals, power, metallurgy, food, and textiles to reduce pressure, release pressure, and stabilize pressure for gases, liquids, and steam.