Comparison between FF bus solenoid valves and A-SI bus solenoid valves.
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Please discuss the advantages and disadvantages of FF bus switch valves and A-SI bus switch valves. There are several projects where bus switch valves are intended to be used; please share your valuable insights! Thank you!
As for bus switch valves, I have never used them (I was involved in a project, but the switch valves there were all 4-20mA type). I can only share my own thoughts: the valves are actually all the same (in terms of materials, valve cores, seatings, etc.); what differs is that FF bus or other buses can be used for signal transmission. If a bus is used, it certainly won’t be the FF bus for optical switch valves; instead, bus signals will be used for all instruments or most of them, with the selection being made based on whether the signals go from the field instruments to the control system. To the best of my knowledge, among the domestic petrochemical plants that use the FF bus, SECCO and the Fujian refining and chemical integration project under construction utilize the FF bus; however, switch valves in these plants still use 4-20mA signals.
You may know relatively little about it. In China, it became useful in the 1990s; the FF bus is already widely used in the petrochemical industry. It’s only in recent years that switches and valves have used buses; several projects have also been carried out using FF and A-SI buses for such devices. It has been in use to this day, and it still works very well; its maintenance and wiring are both simple. However, the stability is slightly not that good. The on/off valve should be a discrete signal, not an analog signal.
Does a wiring box are required when using a bus system? What is the specific installation method? Thank you
Its wiring method is the same as that of the FF bus; there is no difference at all. One card, two ports; one port can support up to 64 points.