A Study of the Freezing Phenomena in PVC and （的研究在PVC和冻结现象）.pdf

A Study of the Freezing Phenomena in PVC and CPVC Pipe Systems Javier Cruz, Bruce Davis, Paul Gramann, Antoine Rios The Madison Group Madison, WI 53711 Abstract Ice Formation in a Piping System Residential and commercial piping systems often As water undergoes a phase transition from liquid to solid experience complex failures from freeze events. In this the density decreases. The orientation of molecules in ice paper the freezing failures are studied by replicating pipe results in a structure that occupies more volume than freezing conditions in a laboratory setting. Testing was liquid water. According to the phase transition into ice, as performed on ½ inch (12.5mm) PVC and CPVC pipes. water freezes a net expansion in volume of approximately Pressure and temperature during the freeze event were 9% occurs. This net expansion in volume ultimately monitored and the fracture modes of failed pipes were causes the bursting of plastic pipes. However, failure examined. Freeze events result in excessively high often occurs at a remote section of pipe through an pressures. It has been shown that during a freeze event, indirect mechanism generated by the actual phase change the properties of plastic pipes are advantageous over other expansion at the freeze point. more rigid piping systems. In this study, it was observed that PVC and CPVC pipes were able to sustain over thirty