(and where picking safety integrity levels on burner management systems makes sense)
Safety is always a primary concern at any industrial site, and for good reason. But how much should you pay for that safety? While that question may have seemed blasphemous in days gone by, in today’s highly competitive business environment, unnecessary costs of any kind cannot be tolerated – and that includes safety instrumented systems, of which burner management systems are one type.
Businesses want to optimize every dollar spent and maximize every dollar in return. A right sized safety system delivers the right amount of protection that a facility needs, requiring only the amount of money that can deliver the most risk reduction. This line of thinking becomes especially relevant when trying to identify the correct amount of risk reduction for a legacy burner management system. Selection of an overly conservative replacement system following prescriptive standards can have significant cost impact often without significant additional risk reduction over a BMS that is chosen based on valid safety integrity level selection techniques. The costs associated with upgrading according to prescriptive requirements typically originate from the significant mechanical rework that is required. Sometimes the cost is so high that it doesn’t get management approval.
This is where the red flags in the executive suites can start to rise as they start sensing unjustified cost escalations or unmitigated risk exposure. Yes, they want safety, but they want it in context of what they need – enough safety that makes the risk tolerable for the business.
“Right sizing” your BMS starts from a good targeted risk assessment of the BMS and fired equipment operation. A good assessment is the one that has a reasonably accurate estimate of likelihood and consequence. If the estimated likelihood is too frequent, or the consequence too severe, the safety integrity level (SIL) target may be set too high. This will result in an overly conservative and unnecessarily expensive system.
On the other hand, if the consequence or likelihood is judged too low, the facility’s risks may not be adequately reduced. This also exposes the business to risks that could be ruinous; risks that the business is trying to mitigate.
At the same time, the system design also needs to be consistent for similarly situated, similar types of fired equipment. The current prevalent techniques of assessing risk needs to be paired with the right amount of empirically backed experience to achieve this. This is where it pays to have a competent engineering partner that can help calibrate and deliver a right sized solution.