Prepared by the Earthquake-Actuated Automatic Gas Shutoff Systems Standards Committee of the Codes and Standards Activities Division of the Structural Engineering Institute of ASCE

This standard provides current minimum functionality requirements for earthquake-actuated automatic gas shutoff devices. These devices contain both a means of sensing seismic activity and a way of shutting off the flow of gas. Applicable to systems carrying natural gas and propane, the devices are used in piping, equipment, and the appliances typically found in structures of three stories or less.

Topics include:

• An overview of applicability, operation, marking, and warranty for these devices;
• Construction issues, such as equipment and data to be provided by the manufacturer, corrosion and chemical resistance, instructions, and continued operation;
• Performance issues, including rigidity of mounting, deflection limits, test specimens, ruggedness, performance requirements, and durability;
• Definitions and references; and
• Detailed commentary with explanatory and supplementary information.

The seismic performance requirements established in this standard are based on dynamic testing of current devices and in-depth examination of data on ground motions, structural damage, fire initiation, and actuation of existing earthquake shutoff devices. This new edition, which updates the previous Standard ANSI/ASCE/SEI 25-06, provides greater transparency regarding the performance of these devices.

Standard ANSI/ASCE/SEI 25-16 is a primary reference for structural and mechanical engineers incorporating gas shutoff devices and systems into a design. It also will be of interest to manufacturers, inspectors, insurers, and owners in seismically active areas.