Can combustible gas probes and flame probes be connected directly to the DCS system?
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The combustible gas probe outputs a 4-20mA signal, while the flame probe provides a DI signal. Neither type of probe triggers any interlock actions when an alarm is triggered; from a technical perspective, there should be no problem with this. However, the design cannot be approved as it stands – it’s required to be integrated into the F&G system. But our expanded station doesn’t have such a system, so it would have to be incorporated into the SSS system, which implies the need to reinstall the lower-level programs. :( I wonder if there is any regulatory basis for such a requirement?
Technically, it’s definitely possible. It’s best to have the manufacturer provide installation services, so there’s no need to worry about anything, or at least get guidance over the phone
What system is SSS? I’m hearing about it for the first time.
Theoretically, there are no issues, but the algorithms and logic for combustion control are likely beyond the capabilities of ordinary DCS companies; it is necessary to entrust them to specialized firms to develop such subsystems
You’ve surely heard of safety shutdown systems, or safety instrumented systems, which are similar to ESD
Oh, both FGS and ESD actually use SIS safety instrument systems
:'(It’s GreenTech’s equipment: the flame sends a DI signal, while the combustible gas generates a 4-20MA signal; an alarm is triggered when this signal reaches a certain value. No algorithms are required at all. This design makes no sense. To reinstall the program in the SSS system, the system has to be reset, which results in the entire plant coming to a stop.)
There are regulations regarding this; must probes of this type be integrated into the safety instrumented system?
There is no strict requirement to design an FG (Flame Gas) system; the project we built last year had combustible and toxic gases fed into the DCS, while a separate fire panel was used for fire detection – no FG or SIS systems were installed. There is even no basis for entering SSS. But there is one thing you need to note: the power supply for the flame detector should not be 24VDC. If there is anything else you need to know, feel free to leave a message.
SH3063-1999 _ Design Code for Detection and Alarm of Flammable and Toxic Gases in Petrochemical Enterprises
Oh, thank you. But GreenTone’s flame probe supports 24V, which means that the fire control panel you have set up separately is actually also a DCS system? Our design is based on this principle; unless you have a dedicated fire panel, it’s necessary to use the Safety Instrumented System L – which involves issues related to higher safety factors Is it the designers who are afraid of taking responsibility, or what’s going on? It’s just for alarm purposes; aren’t DCS alarms and SSS alarms the same thing?……