Thermal Expansion/Contraction

GF Harvel EnviroKing®UV piping will expand and contract with changes in temperature. This issue must be addressed with appropriate system design—and during installation—to prevent damage to the piping system. The change in length generated as the result of temperature changes must be calculated based on the anticipated change in temperature that the system will be exposed to. The coefficient of linear expansion for GF Harvel EnviroKing®UV pipe is 3.9 x 10-5 in./in./°F. The rate of expansion or contraction can be calculated as follows:

ΔL = 12 yL (ΔT) where:
ΔL = expansion or contraction in inches
y = 3.9 x 10-5 (coefficient of linear expansion)
L = length of piping run in feet
ΔT = temperature change °F
(T max. - T@ installation)

In many cases the movement caused by thermal expansion/contraction must then be compensated for by the construction of appropriately sized expansion loops, offsets, bends, or the installation of expansion joints. These configurations will absorb stresses generated form the movement, thereby minimizing damage to the piping. The effects of thermal expansion and contraction must be considered for systems involving long runs, and particularly piping systems exposed to environmental temperature extremes (i.e., exposed outdoors, summer to winter). Additional detailed information pertaining to thermal expansion/contraction can be found here or by contacting GF Harvel Technical Services at 610-252-7355.