In my consulting I often hear engineers say, “I think I have too many detectors”.  They use their prescriptive rules, other rules of thumb, and basic engineering judgment to perform an initial layout and when the design is complete they look at the thousand or so detectors they’ve placed and determine that it just doesn’t feel right.

Unfortunately, in recent history and in many cases today’s design practices don’t give these engineers any objective criterion upon which to reduce the detector count, or even provide a rational yardstick to determine whether or not their count of detectors is reasonable given the type of facility that they are operating.

That has all changed.  Kenexis has been assisting our customers with performance based fire and gas designs for over 5 years now, and we have built up a significant library of studies from which we can pull statistics on what is typical of a “well done” design.  We have also now developed a methodology to review a facility very rapidly to develop a coarse (+/- 30%) count of detectors that are expected to be required if the facility were designed using the latest state-of-the art performance based fire and gas detection techniques.  Our process uses shortcut risk analysis methods that consider each major equipment item in terms of type, operating temperature, operating process, and composition of material contained in the equipment item, and determine whether or not we would expect that equipment item to require protection from an FGS.  We then apply a scaling factor (based on past experience) that ratios the number of expected detectors to the number of equipment items that are expected to require coverage by FGS.

Using this method we can quickly estimate the expected number of detectors of each type for a facility of almost any size, usually for less than $10,000 USD.  So whether you need an estimated number of detectors for FEED stage cost estimation purposes, a review of the design of an existing facility, or a sanity check of a proposed design of a new facility.  We can help in a quick and efficient manner.  Let us know how we can help you.