API RP 2028:2002 (R2010)

The scope of this recommended practice is the use and limitations of flame arresters installed in piping systems in the petroleum and petrochemical industries. It provides a general overview of flame arresters currently in use and some potential concerns or limitations. Applicable combustion and flame propagation parameters are discussed including the distinction between arresting flames versus arresting detonations. This recommended practice is neither a design manual nor a regulatory compliance document. It does provide reference to more detailed technical discussions of flame arresters and combustion. Various standards, codes, and regulations are noted in the Section 2 references and in the Appendix A Bibliography. PURPOSE This recommended practice is intended to inform industry about limitations of flame arresters installed in piping systems. Concerns about potential environmental effects of hydrocarbon and chemical vapor emissions have led to regulations requiring the installation of vapor control systems. In the United States, for marine transfer of oil or hazardous materials, United States Coast Guard regulations require installation of flame arresters (suitable to interrupt a detonation) in vapor control piping. These USCG regulations specifically direct (in detail) where to install these flame detonation arresters in the vapor control systems. An independent laboratory must test detonation arresters installed to meet these regulations. The diversity of commercial flame arresters can lead to the installation of these arresters in piping systems where the conditions within the piping may be significantly different from the conditions for which they were designed, or tested and listed by testing laboratories. Under certain conditions, flames propagating through piping systems can reach velocities and pressures at which detonation can occur. Unless a flame arrester has been designed and tested for a detonation, it may not stop the progression of a combustion wave in the piping. Guidance is provided concerning the important factors involved in the selection, installation and maintenance of appropriate flame arresters. The intent is to assist the user of this recommended practice in developing the awareness of review needs, and to encourage discussions with flame arrester manufacturers regarding specific applications and test results.