Throttle device pressure tapping port
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A throttling device is equipped with two transmitters, one of which feeds data to the DCS and the other to the SIS. Question: Must the pressure tapping ports of two transmitters be independent? Can a pair of pressure taps be used together?
This can be handled with a transmitter that feeds directly into the SIS and then communicates with the DCS; there’s no need to set up two systems, right? I’ve only been in this field for a short time, and that’s how it’s always been done in the examples I’ve seen
It is best to be independent, which facilitates maintenance and system security.
If there are too many process connection joints, it increases the failure rate. Why not use the same transmitter and a one-input two-output signal distributor to solve this issue?
The pressure tapping points of the two transmitters must be independent
I’ve encountered a case where two transmitters were installed at the pressure tapping point (I’ve seen this happen once or twice in my three or four years in the instrumentation industry); it might work. If it doesn’t work, could it be that the pressure is dispersed to the two transmitters after being taken from the pressure tap, which affects the transmission of pressure and leads to errors? I’m not very familiar with automated instruments – is it possible for one transmitter to output two signals? I think it should be possible.
The pressure tapping point is installed downstream of the throttling device; it is recommended to consult the relevant standards first, namely the «Code for Design of Safety Instrumentation in Petrochemical Industries – GB_T50770-2013»
A transmitter with two signal channels will do. . . Doing so much of this
Preferably, DCS and SIS should have separate pressure tapping points as well as separate root valves. As a secondary option, share a pair of pressure taps, but keep the root valve separate. Note: Do not use it if the material is suspected of blocking the pressure guide tube. @jiaguoyun @Big Horse with Big Bow
One set of pressure tap pipes and one transmitter are sufficient; then the one-input two-output safety barrier can be connected to the DCS and SIS. It’s not a case of needing triple redundancy, so there’s no need for such waste