What is the difference between a programmed control valve for pressure swing adsorption and a regular shut-off valve?
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During the pressure swing adsorption process, the programmable valve simply serves to open and close the pipeline; it opens the air supply through a solenoid valve and then closes it by reversing the direction of airflow. What is the difference between this and a regular pneumatic shut-off valve? Why is it called a programmable control valve, and why are there so many applications for it in chemical processing plants? I would appreciate it if you could share your insights. Thank you!
There are many of them, also known as cut-off valves; they use solenoids to control the intake and exhaust of air in the cylinder, thereby controlling whether the valve is fully open or fully closed.
In pressure swing adsorption, a programmable valve is a valve whose on/off state is controlled by a program. Compared to ordinary shut-off valves, it operates frequently, needing to be switched within just a few seconds, which means higher requirements are placed on such valves than on ordinary shut-off valves.
Pneumatic globe valves can also be controlled via a program, and other shut-off valves can be controlled in the same way. Then why aren’t pneumatic globe valves called programmable valves?
The biggest difference is that a programmable valve has only two states: fully closed and fully open. In contrast, the opening degree of a regular cut-off valve can be adjusted arbitrarily
Can a pneumatic globe valve be used as a programmable valve? If not, please explain the reason. Thank you
Ordinary cut-off valves are also operated frequently; the pneumatic switching speed is generally within 5 seconds, and such valves can also be controlled via a program. So can’t they be distinguished in this case? ?
A regular cut-off valve can only have its opening degree adjusted arbitrarily when equipped with a positioner. So, can the valve position also be adjusted arbitrarily if a programmable valve is equipped with a positioner as well?
A programmable valve, as the name suggests, is a valve that is controlled by a program; it is operated under centralized control by a PLC. It opens and closes frequently, which means that very high performance requirements are placed on such valves in pressure swing adsorption systems. The packing used in these valves differs from that of other shut-off valves, and strict requirements are imposed on the sealing mechanism of the valve body to prevent air leakage during operation. The power source for these valves can be pneumatic or hydraulic, with the appropriate type being selected depending on the specific operating conditions
Are there only two states? The adsorption time is controlled programmatically, with full operation within a certain time range
The solenoid valve is used to control the intake and exhaust of the cylinder, thereby controlling the valve to be fully open or fully closed