Many plants must contend with outdated burner management systems (BMSs) on all sorts of equipment — boilers, process heaters, thermal oxidizers, incinerators, reformers, vaporizers, dryers, ovens, sulfur recovery units, kilns, calciners, furnaces, etc. Some of these brownfield installations may date back 40 years or more. Most systems originally were designed according to prescriptive standards, almost a “cookbook” approach. Numerous logic systems in use still are based on relays or other technologies that are becoming obsolete and difficult to support. Many older fuel-train-valve arrangements are non-redundant, yet current standards mandate double-block-and-vent valves. Myriad existing systems require a variety of changes and upgrades — but trying to bring all systems up to current standards is both problematic and potentially very costly.
For example, some systems have 40 or more fuel lines. Installing extra block-and-vent lines (per current codes) would be cost prohibitive, especially considering that many companies have numerous such systems at multiple sites.
However, some interesting things have happened with standards in the last ten years. Back when the ISA 84 committee started working on the technical report for BMSs, most of the prescriptive BMS standards in industry — such as those from the National Fire Protection Association (NFPA) and American Petroleum Institute (API) — had not embraced or invoked the safety lifecycle. As of 2015, all the BMS series of NFPA standards (85, 86 and 87) have invoked the safety lifecycle. For brownfield installations with perhaps dozens of very similar systems that may require upgrades, this represents a significant opportunity.