CSSBI SSF 19-05: Explosion Venting for Steel Frame Buildings

Executive Summary The aim of this fact sheet is to advocate an alternative solution for the Steel Industry in regards to restrictive code provisions for explosion venting that are now mandated by the Ontario Fire Code (OFC). Due to a September 2000 amendment of code provisions dealing with explosion venting in the OFC, explosion vent designs were required to be in conformance with NFPA 68, the National Fire Protection Association’s (NFPA) Guide for Venting of Deflagrations. NFPA 68 gives a prescriptive solution that has upper bound limits on size and mass of an explosion vent panel, which the Steel Industry finds are too small to be practical. The Canadian Steel Construction Council (CSCC) investigated this problem and identified an alternate design guideline from the Factory Mutual Insurance Company’s (FM) Property Loss Prevention Data Sheets, numbered 1-44 and entitled “Damage Limiting Construction”. FM’s 1-44 Data Sheets can be used to develop an alternate solution for explosion venting that exceed the size and mass limits of the NFPA 68 prescriptive solution, and can be submitted for approval under the Compliance Equivalency provisions in the OFC. With the introduction of an objective based National Building Code Canada (NBCC) in 2005 followed by Provincial code adoptions in 2006 it would be worthwhile to establish a precedent through the Compliance Equivalency provision in the OFC. Once a precedent setting case occurs, the “acceptable solution” or “compliance alternative” would go on record and aid in resolving subsequent proposals for Compliance Equivalency, and also support a future technical change in the OFC. The CSCC by way of this fact sheet would advocate this alternative solution for the Steel Industry when designing explosion vent panels in steel framed buildings.