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NFPA 56 (PS) provides for life safety during the internal cleaning of flammable gas piping systems in power plants and industrial/commercial applications.

This all-new Standard is issued in response to urgent recommendations by the U.S. Chemical Safety Board following a tragic incident at a power plant under construction. NFPA 56 (PS): Standard for Fire and Explosion Prevention During Cleaning and Purging of Flammable Gas Piping Systems provides minimum safety requirements for the cleaning and purging procedures of flammable gas piping systems for electric-generating plant, industrial, institutional, and commercial applications. Coverage of piping systems extends from the point of delivery to the equipment shutoff valve, including all valves, regulators, and other appurtenances.

Requirements were developed by an ANSI-balanced committee made up of industry experts.

NFPA 56 (PS) applies to all flammable gas piping systems, including those in electric-generating plants, refineries, petrochemical plants, and other commercial and industrial applications.

The 2012 edition of NFPA 56 (PS):

• Prohibits the use of flammable gas for internal cleaning of piping systems.
• Provides guidance for purge end-points of many common flammable gases used in industrial and fuel gas applications.
• Covers activities including cleaning new or repaired piping systems, placing piping systems into service, and removing piping systems from service.
• Requires development of written procedures and a safety validation of procedures by competent persons.

An informational example of a purge procedure provides users with valuable guidance in using the Standardand meeting the intent of the requirements. NFPA 56 (PS) is a critical reference for designers, operators, and contractors responsible for the design, construction, and commissioning of flammable gas piping systems.