Where is the double cylinder regulating valve used?
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Dear teachers, have you ever used a dual-cylinder regulating valve? How is the positioner air circuit connected? Any pictures? Is it because the diameter of the regulating valve is too large that the manufacturer made it double cylinder?
Double-cylinder regulating valves are often used in places where precise flow control is required, such as industrial production, equipment maintenance, etc. The connection of the positioner air circuit mainly depends on the specific configuration of the positioner and actuator, which usually includes input signal, air supply, positioner, actuator and other parts. Sorry, I can't provide image information. The dual-cylinder design is not entirely due to the large diameter of the regulating valve. The main purpose of this design is to provide greater power for faster and more precise flow regulation. Of course, if a system requires a larger flow adjustment range, it may be necessary to use a larger diameter regulating valve. In this case, a dual-cylinder design may also be used. Different systems and application scenarios may require different configurations and designs. Therefore, there are multiple designs such as dual cylinders and single cylinders. .
This is the first time I saw a double diaphragm regulating valve: lol
. The two diaphragm head output shafts of this double diaphragm head pneumatic diaphragm actuator are rigidly connected (can be regarded as one shaft). When connecting the air path, you only need to install a tee on the pneumatic signal (positioner output) to directly distribute the pneumatic signal to the two diaphragm heads. When adjusting, you can only look at the lower membrane head and operate it as a single membrane head. It is not necessary to use double membrane heads. But this has certain advantages: A larger thrust can be obtained with the same diaphragm head diameter. ； Occupies a small area in a certain direction ； The stroke of the diaphragm head will be slightly larger than that of the diaphragm head with the same diameter or thrust. ； To a certain extent, the two membrane heads can back up each other. Personal experience using double diaphragm head pneumatic diaphragm actuator: It is more suitable for installation on pipelines that require frequent switching or where multiple control valves are installed in concentrated locations. ； The failure rate of diaphragm and shaft seal diaphragm is higher than that of ordinary single diaphragm head. ； If possible, a stop valve (ball valve) can be installed at the gas signal inlet of the two membrane heads, which will help determine which membrane head has a problem and provide mutual backup (when thrust is not considered, cutting off the signal of one membrane head will not affect the stroke).
At first glance, it is our Sichuan Yi valve. It is mainly used in places where the space is small and requires a large torque. I use this kind of double membrane head:lol:lol:lol
The diaphragm type adjustment effect is good, the closing pressure difference of a single diaphragm head is small, and the closing pressure difference of a double diaphragm head is large. The valve on site should be a single-seat plunger. If it is a cage type, there is no need to use two heads: D
“The statement "double-cylinder regulating valve" is wrong. The double-diaphragm actuator requires large thrust!
The double membrane head actuator requires large thrust! Many double-acting cylinders of on-off valves are also dual-cylinders connected in series, which saves space and provides high thrust!
I can see the locator, it’s from Sichuan Instruments: lol, I’ve also used that locator.