NFPA 56:2023

Chapter 1 Administration 1.1 Scope. 1.2 Purpose. 1.3 Coordination. 1.4 Retroactivity. 1.5 Equivalency. Chapter 2 Referenced Publications 2.1 General. 2.2 NFPA Publications. 2.3 Other Publications. 2.4 References for Extracts in Mandatory Sections. Chapter 3 Definitions 3.1 General. 3.2 NFPA Official Definitions. 3.3 General Definitions. Chapter 4 General Requirements 4.1 Piping System Construction. 4.2 Temperature and Pressure. 4.3 Cleaning and Purging Procedures. 4.4 Safety Validation. 4.5 Management of Change. 4.6 Documentation. 4.7 Notification of Hazards. 4.8 Evacuation of Affected Area. 4.9 Segment Cleaning. 4.10 Hangers and Supports. 4.11 Nonflammable Atmosphere. 4.12 Utility Coordination. 4.13 Restricted Access.Chapter 5 Training Requirements 5.1 Training. Chapter 6 Cleaning 6.1 Cleaning of Flammable Gas Piping. 6.2 Cleaning Media. 6.3 Temporary Power/Fuel Supply. 6.4 Temporary Piping (Including Hose Assemblies). 6.5 Pig Cleaning. 6.6 Target. 6.7 Isolation and Protection of Clean Piping Systems or Segments. Chapter 7 Purging into Service 7.1 Charging Piping System with Flammable Gas. 7.2 Discharge of Purged Gases. 7.3 Detection Equipment. Chapter 8 Purging out of Service 8.1 When to Purge out of Service. 8.2 Isolation. 8.3 Charging with Inert Gas. 8.4 Discharge of Purged Gases. 8.5 Detection Equipment. Annex A Explanatory Material Annex B Purge End Points for Common Flammable Gases Annex C Sample Purge Procedure Annex D Human Factors Considerations Annex E Informational References

This standard shall apply to ƒre and explo‐sion prevention during cleaning and purging activities for new and existing …ammable gas piping found in electric-generating plants, process plants, and industrial, institutional, and commercial applications.