Basic knowledge of valves
Thread Content
Valves are control components in pipeline fluid transportation systems; they are used to change the cross-sectional area of the flow path and the direction of fluid flow, and have functions such as guiding flow, shutting off flow, regulating flow, throttling, preventing backflow, diverting flow, or relieving pressure through overflow. *Valves used for fluid control range from the simplest globe valves to various types of valves employed in highly complex automated systems; there is a great variety of such valves, with nominal diameters ranging from the extremely small sizes of instrument valves to those of industrial pipes with diameters up to 10 meters. Valves can be used to control the flow of various types of fluids, including water, steam, oils, gases, muds, various corrosive substances, liquid metals, and radioactive fluids. The operating pressure of valves can range from 1.3×10^7 MPa to ultra-high pressures of 1000 MPa, while the operating temperature can range from extremely low temperatures of -269°C to high temperatures of 1430°C. Valve control can be achieved through various actuation methods, such as manual, electric, hydraulic, pneumatic, worm gear, electromagnetic, electro-hydraulic, electro-pneumatic, pneumatic-hydraulic, spur gear, bevel gear drive, etc ； It can operate according to predetermined requirements in response to signals from pressure, temperature, or other sensors, or it can simply open or close without relying on such sensors. The valve uses driving or automatic mechanisms to cause the moving parts to move up and down, slide, swing, or rotate, thereby changing the size of its flow passage and thus fulfilling its control function. ‑The purpose of the y2}JN‑B I valve )v1\} {6] is to serve as a piping accessory; it is a device used to change the cross-sectional area of the flow path and the direction of fluid flow, thereby controlling the movement of the medium being transported. It has functions such as guiding flow, shutting off flow, regulating flow, throttling, acting as a check valve, splitting flow, or releasing pressure through overflow. Specifically, valves have the following uses: 1.1 Shut-off valves: to connect or disconnect the fluid in various sections of a pipeline. Such as gate valves, globe valves, ball valves, plug valves, diaphragm valves, butterfly valves, etc. nu;BP3
II Classification of Valves ZsZfGYfQu – There are a wide variety of valves, and as the processes and performance of various types of complete equipment continue to improve, the number of valve types is also increasing. Generally speaking, however, they can be divided into two main categories: \=2m4+
III Classification by main parameters 0: 3.1 Classification by pressure: 7< +VGXr 3.1.1 Vacuum valves – valves that operate at pressures below standard atmospheric pressure, with an absolute pressure of less than 0.1 MPa (i.e., 760 mm of mercury), as well as valves that can function at 450°C. EA~eMEFP 3.2.4 Bottom temperature valve – a valve for temperatures ranging from -100℃ to -40℃. SXkZN;4>: 3.2.5 Ultra-low temperature valves -- t
It’s recommended to attach a file; it’s a bit messy.
Exactly. And there’s also some garbled text; it would be great if that garbled text could be edited before pasting it