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Estimates of the Operational Reliability of Fire Protection Systems.


pdf icon Estimates of the Operational Reliability of Fire Protection Systems. (923 K)
Bukowski, R. W.; Budnick, E. K.; Schemel, C. F.

Fire Protection Strategies for 21st Century Building and Fire Codes Symposium. EXTENDED ABSTRACTS. Proceedings. Society of Fire Protection Engineers and American Institute of Architects. September 17-18, 2002, Baltimore, MD, 111-124 pp, 2002 AND International Conference on Fire Research and Engineering (ICFRE3), Third (3rd). Proceedings. Society of Fire Protection Engineers (SFPE), National Institute of Standards and Technology (NIST) and International Association of Fire Safety Science (IAFSS). October 4-8, 1999, Chicago, IL, Society of Fire Protection Engineers, Boston, MA, 87-98 pp, 1999, 2002.

Keywords:

fire research; fire protection engineering; fire protection; evaluation; fire detection; fire suppression; reliability; literature reviews; uncertainty; smoke detectors; sprinklers; sprinkler systems

Abstract:

Fire protection strategies are designed and installed to perform specific functions. For example, a fire sprinkler system is expected to control or extinguish fires. To accomplish this, the system sprinklers must open, and the required amount of water to achieve control or extinguishment must be delivered to the tire location. A fire detection system is intended to provide sufficient early warning of a fire for occupant notification and escape, fire service notification, and in some cases activation of other fire protection features (e.g., special extinguishing systems, smoke management systems). Both system activation (detection) and notification (alarm) must occur to achieve early warning. Construction compartmentation is generally designed to limit the extent of fire spread as well as to maintain the building's structural integrity as well as tenability along escape routes for some specified period of time. In order to accomplish this, the construction features must be fire "rated" (based on standard tests) and the integrity of the features maintained. The reliability of individual fire protection strategies such as detection, automatic suppression, and construction compartmentation is important input to detailed engineering analyses associated with performance based design. In the context of safety systems, there are several elements of reliability, including both operational and performance reliability. Operational reliability provides a measure of the probability that a fire protection system will operate as intended when needed. Performance reliability is a measure of the adequacy of the feature to successfully perform its intended function under specific fire exposure conditions. The former is a measure of component or system operability while the latter is a measure of the adequacy of the system design. The scope of this study was limited to evaluation of operational reliability due primarily to the form of the reported data in the literature. In addition to this distinction between operational and performance reliability, the scope focused on unconditional estimates of reliability and failure estimates in terms of fail-dangerous outcomes. A discussion of these terms is provided later in the paper. This paper provides a review of reported operational reliability and performance estimates for (1) fire detection, (2) automatic suppression, and to a limited extent (3) construction compartmentation. In general, the reported estimates for tire detection are largely for smoke detection/fire alarm systems; automatic sprinklers comprise most of the data for automatic suppression, and compartmentation includes compartment fire resistance and enclosure integrity. It should be noted that in some cases the literature did not delineate beyond the general categories of "fire detection" or "automatic suppression," requiring assumptions regarding the specific type of fire protection system.