Flame Arresters in Piping Systems

API RECOMMENDED PRACTICE 2028 THIRD EDITION, FEBRUARY 2002

REAFFIRMED, JUNE 2020

Flame Arresters in Piping Systems

Downstream Segment

API RECOMMENDED PRACTICE 2028 THIRD EDITION, FEBRUARY 2002

REAFFIRMED, JUNE 2020

SPECIAL NOTES

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API is not undertaking to meet the duties of employers, manufacturers, or suppliers to warn and properly train and equip their employees, and others exposed, concerning health and safety risks and precautions, nor undertaking their obligations under local, state, or fed- eral laws.

Information concerning safety and health risks and proper precautions with respect to par- ticular materials and conditions should be obtained from the employer, the manufacturer or supplier of that material, or the material safety data sheet.

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Copyright ? 2002 American Petroleum Institute

FOREWORD

This recommended practice was prepared under the direction of the API Safety and Fire Protection Subcommittee. This third edition of API 2028 Flame Arresters in Piping Systems has been extensively rewritten and updated from the previous edition. Appendices to the doc- ument are intended to provide additional supplementary information.

This guide was prepared to help provide a basic understanding of ?ame arresters used in piping systems. The information presented is based primarily upon experience in the petro- leum industry. It is not intended to exclude or limit the use of other approaches of compara- ble merit. Because of the special nature of ?ame arresters, especially those used for detonation protection, this recommended practice strongly encourages dialogue with the equipment supplier and the use of sound engineering judgement in ?ame arrester selection and application.

iii

APPENDIX A BIBLIOGRAPHY 9

APPENDIX B GASES OR VAPORS WITH A MAXIMUM EXPERIMENTAL

SAFE GAP (MESG) < 0.90 MM 11

v

Flame Arresters in Piping Systems

SECTION 1—INTRODUCTION

1. PURPOSE

   This recommended practice is intended to inform industry about limitations of ?ame arresters installed in piping systems. Concerns about potential environmental effects of hydrocar- bon 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 materi- als, United States Coast Guard regulations require installation of ?ame arresters (suitable to interrupt a detonation) in vapor control piping. These USCG regulations speci?cally direct (in detail) where to install these ?ame detonation arresters in the vapor control systems. An independent laboratory must test detonation arresters installed to meet these regulations.

   The diversity of commercial ?ame arresters can lead to the installation of these arresters in piping systems where the con- ditions within the piping may be signi?cantly different from the conditions for which they were designed, or tested and listed by testing laboratories. Under certain conditions, ?ames propagating through piping systems can reach velocities and pressures at which detonation can occur. Unless a ?ame 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 ?ame arresters. The intent is to assist the user of this recommended practice in developing the awareness of review needs, and to encourage discussions with ?ame arrester manufacturers regarding speci?c applications and test results.

   
   

2. SCOPE

   The scope of this recommended practice is the use and lim- itations of ?ame arresters installed in piping systems in the petroleum and petrochemical industries. It provides a general

   overview of ?ame arresters currently in use and some poten- tial concerns or limitations. Applicable combustion and ?ame propagation parameters are discussed including the distinc- tion between arresting ?ames 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 ?ame arresters and combustion. Various standards, codes, and regulations are noted in the Section 2 references and in the Appendix A Bib- liography.

   
   

3. CONCEPT OF HAZARD VS. RISK

   Hazards are properties of materials with the inherent ability to cause harm. Flammability, toxicity, corrosivity, stored chem- ical or mechanical energy all are hazards associated with vari- ous industrial materials. Risk requires exposure. The

   ?ammability of a material transported in piping is an inherent hazard, but becomes a risk only when having access to an oxi- dizer and being exposed to an ignition mechanism. There is no risk of ignition when there is no potential for those exposures. Determining the level of risk involves estimating the probabil- ity and severity of exposure conditions that could lead to harm.

   
   

4. RETROACTIVITY

Any provisions in this recommended practice related to design are intended for reference when designing new facili- ties or when considering major revisions or expansions. It is not intended that any recommendations in this recommended practice be applied retroactively to existing facilities unless deemed appropriate based on facility review. Each facility must make their own determination regarding how to comply with any applicable regulations.

SECTION 2—REFERENCED PUBLICATIONS

The most recent edition or revision of each of the following standards, codes, and regulations are cited in this recom- mended practice. Additional references not speci?cally cited in this document are listed in the Bibliography, Appendix A.

API1

Std 2000 Venting Atmospheric and Low-Pressure Storage Tanks

1www.api.org

1

RP 2210 Flame Arresters for Vents of Tanks Storing Petroleum Products

ASTM2

F 1273 Standard Speci?cation for Tank Vent Flame Arresters

2American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, Pennsylvania, USA 19428. www.astm.org