Seismic response of pressurized fire sprinkler piping systems I: Experimental study

This first of two companion articles presents the results of an experimental program designed to evaluate the seismic behavior of fire extinguishing sprinkler piping systems. Three full-scale pressurized sprinkler piping specimens made of different materials and joint arrangements were tested with various levels of seismic bracing under dynamic loading on the University at Buffalo Nonstructural Component Simulator. All three fully braced specimens performed well under a Maximum Considered Earthquake (MCE) level of loading, validating current code-based requirements for bracing system design. However, unbraced systems, which are typically installed in low to moderate seismic regions or could exist in older construction in active seismic zones, did not perform as well as the fully braced systems. Damage to sprinkler heads, failures of vertical hangers, as well as a complete branch line fracture, were observed during the tests.