Classification of valves
Thread Content
I just saw a post on the forum asking for photos of valves; everyone was eager to contribute, but after seeing those photos I felt very worried, so I’m posting this to encourage everyone to share their opinions! I. Valves can be classified by control method as follows: 1. Automatic – and based on the type of actuator, they can be pneumatic, electric, or hydraulic. 2. Manual – and depending on the structure of the manual operating device, they can be those with a assisting mechanism or without one. II. Based on their structural design, valves can be categorized as single-seat, double-seat, cage-type valves, ball valves, butterfly valves, gate valves, and plug valves. III. According to the way in which they open, valves can be divided into straight-stroke and rotary-stroke types. In our field of automatic control, we usually deal with valves that come equipped with actuators; therefore, companies such as BIFFI, Rotork, and BETTIS mentioned in that post are manufacturers of actuators, not valves. To identify a valve brand, we should look at the markings on the valve body, rather than the label on the actuator. Also, the two pictures of butterfly valves mentioned in that post are actually manual gate valves, not butterfly valves. I don’t mean anything by it; I just hope our forum becomes more professional and that there are no conceptual misunderstandings!
There are many ways to classify control valves; based on the actuator, they can be divided into pneumatic control valves, electric control valves, and hydraulic control valves； Classified by flow path, there are straight-through valves, three-way valves, angle valves, etc ； Classified by the throttling element, they include single-seat valves, double-seat valves, ball valves, butterfly valves, cage valves, diaphragm valves, etc ； Based on the movement mode of the valve stem, there are linear stroke control valves and rotary stroke control valves; there are also other classification methods. 、