Seismic Performance of Chlorinated Polyvinyl Chloride Sprinkler Pipes

A major concern about chlorinated polyvinyl chloride (CPVC) pipes is the large swing of branch lines during earthquake-induced motions. National Fire Protection Association (NFPA) 13 defines spacing requirements for braces and restraints, based on pipe-bending strength, but does not limit the swing. Shake table tests and numerical simulations show that the swing of CPVC branch lines can be limited to an acceptable level if the ends are braced and the spacing of restraints follows the NFPA 13 requirements for CPVC, or if restraint spacing is reduced to about half of that currently allowed in NFPA 13.