Study of the effect of temperature on failure behaviour of locality manufactured PVC pipes

Abstract

An experimental investigation of the effect of testing temperature on the internal pressure sustaining capacity of locally manufactured polyvinyl chloride (PVC) pipes is presented in this thesis. An experimental set-up consisting of a constant temperature bath, temperature control devices and a pressurizing device is designed, fabricated and installed for the investigation. It is observed from the experimental results that there is significant effect of temperature on the mean failure pressure characteristics of the PVC pipes. With the increase of the temperature, the failure pressure decreases remarkably. For a wide range of temperature, from 10°C to 50°C, the experimental investigation is carried out. At each temperature, a reasonable number of samples .for the study is considered and the mean failure pressure is calculated. An empirical relation between mean failure pressure and temperature is also introduced. Two types of failures such as brittle failure and ductile failure are observed in the study. At low temperature failure of pipes occurs with almost no swelling of the pipe due to their brittle nature,. while as the temperature rises, the ductility of pipe material rises and the failure of pipes occurs with swelling effect. The calculated values of mean hoop stress obtained from the experimental data for the PVCpipes are shown with the available results of hoop stress for high density polyethylene ( HDPE ) pipes.