Back in 2015, I posted a discussion here in EE365 on the “hidden” Safety Instrumented System (SIS) in your legacy control system. Back then, I posed the question – is there a SIS “hidden” in your legacy process control system you are modernizing? Earlier this year I presented at a local Emerson user meeting about modernizing a Burner Management System (BMS) and I like to pose a similar question – is there a Safety Instrumented System (SIS) in your old BMS?
Before we delve into that, let’s recap what is a Burner Management System (BMS) is. A BMS is a critical component of every combustion process whether it be a boiler, heater, kiln, dryer, thermal oxidizer, incinerator or other unit. This is the system that protects against hazardous firing conditions, which could result in harm to the process equipment and any personnel around it. BMS’s come literally in all shapes and sizes and modernizing a legacy BMS to comply with today’s process safety standards and codes can be a challenge.
So back to the question – is there a SIS in your BMS? Legacy BMS’s can come in the form of proprietary “black boxes”, hardwired relays, old Programmable Logic Controllers (PLCs) and even embedded in legacy process control systems (as I have suggested before).
My answer is – it depends ... just as BMS’s come in various shapes and sizes, so do the codes and regulations that users choose or are regulated to employ to govern their BMS installation. In the US for example, a significant portion of BMS’s are designed and manufactured around the prescriptive National Fire Protection Association (NFPA). In addition to the NFPA, there are other “Authorities Having Jurisdiction” like insurers/underwriters to consider. In other World Areas, there are National Standards and Authorities that govern for each country so the answer there is even more complex.
With that in mind, a best practice for BMS modernization to overcome this would be conduct a process hazards analysis (PHA) to determine what the current risks and hazards are. Burner equipment may have been updated and/or changed overtime. Replacement In Kind is definitely not recommended. Again, always have an up to date PHA as part of your BMS modernization project.
Once you have conducted a PHA, you will have a better idea of what you are dealing with from an SIS implementation perspective. I would advocate that, whenever possible, modernize your legacy BMS with an SIS.
Why modernize a BMS with a SIS? With a modern state-of-the-art SIS’s, you will get the benefits of:
Emerson offers the broadest and deepest SIS modernization solutions in the market, from sensors, to logic solvers to final elements, that enables compliance to process safety standards and codes, supports safe operation while also allowing improved reliability and availability.
Share your thoughts on BMS modernization with me on EE365. Better yet, come visit with the Systems Modernization Team at Emerson Global Users’ Exchange 2018 at San Antonio, Texas October 1 – 5. We look forward to discussing BMS modernization with you.