Thermal expansion & contraction

Like all piping material, Flowline CPVC expand when heated and contract when cooled. CPVC piping (regardless of pipe diameter) will expand about 1 inch per 50 feet of length when subjected to a 23 degree Ftemperature increase, therefore, allowances must be made for this resulting moliement. However, laboratory testing andinstallation experience have demonstrated that the practical issues are much ‘smaller than the coefficient of thermalexpansion would suggest. The stresses developed in CPVC pipe are generally much smaller than those developed in metalpipe for equal temperature changes because of the difference in elastic modulus.

Expansion is mainly a concern in hot water lines; generally, thermal expansion cab be accommodated with the changes indirection. However, a long straight run may require an offset or loop. Only one expanpion loop, properly sized is required in anysingle straight run, regardless of its total length. If more convenient, two or more smaller expansion loops, properly sized, canbe utilized in a single run of pipe to accommodate the thermal movement. Be surelto hang pipe with smooth straps that willnot restrict movement.