Common valves: Gate valves, globe valves, ball valves, butterfly valves – comparison and selection
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I ask experts to compare common valves such as gate valves, globe valves, ball valves, butterfly valves, etc., in terms of their structural features, manufacturing processes, costs, prices, and precautions, so that everyone can have a proper understanding of them and make informed choices: handshake
Comparison is necessary to make distinctions: hug: These are all commonly used valves, so it makes sense to do this; I earnestly ask all fellow users to participate actively! The question might be too broad; it’s not necessary to compare everything, just some parts. . . :lol
The globe valve is the most widely used type of shut-off valve in chemical production. Unlike the three other types of shut-off valves mentioned earlier, it does not open and close by rotating its closing element; instead, it uses the upward and downward movement of the valve stem to move the circular valve disc (valve head) connected to it, thereby changing the distance between the valve disc and the valve seat to control the opening and closing of the valve. Features: The upper part of the globe valve consists of a handwheel and a valve stem; the middle part includes threads and a packing seal section. In the case of small valves, butterfly valves use a disc that can rotate around an axis to control the opening and closing of the pipeline, with the degree of rotation indicating the extent to which the valve is open. Features: Butterfly valves have advantages such as a simple structure, rapid opening and closing, low fluid resistance, and easy maintenance. However, they cannot be used in high-temperature and high-pressure environments, nor in pipelines for large-diameter fluids such as water, steam, air, and oils where the PN value is less than 1.6 Mpa and the temperature is less than 120 degrees Celsius. Ball valves and plug valves are of the same type of valve; the only difference is that their closing element is a sphere with a hole through it, and the sphere rotates around the axis of the valve stem to achieve opening and closing. Features: Simple valve structure, reliable operation; suitable for pipelines with bidirectional flow of media, low fluid resistance, and good sealing performance ； Disadvantage: The medium can easily leak from the valve stem area.
Butterfly valves with metal seals, triple-eccentric design, and torque sealing can be used not only in high-temperature and high-pressure conditions but also in extreme cold, low-temperature environments as well as in applications requiring large diameters. Moreover, there are many different materials from which to choose