T.G. Meyering

Bio: T.G. Meyering is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

The Durability of a Low-pressure Gas Distribution System of Ductile PVC

Abstract: One of the options for a low-pressure gas distribution system is the use of ductile PVC pipes and joints. The long-term performance of ductile PVC pipes has been reported in a number of previous studies. In this paper the long-term performance of the socket joints, in which elastomeric (NBR) sealing rings are used, is evaluated. The long-term quality of socket joints in ductile PVC pipeline systems has been determined by various tests on a number of excavated joints, which have been in operation for more than 20 years. Leak tightness determined according to the present specifications did fulfil all requirements. The quality of the rubberrings , established by e.g. tensile testing and hardness tests, was also still at the level of new rubberrings. The socket joints started only to leak at deflections of the pipes far exceeding the deflection levels met in field practice. The compression set of the excavated samples was also rather low and extrapolated to long times will not exceed a maximum required value of 70 % before 50 years. These results once again show that ductile PVC pipe systems for low-pressure gas distribution exhibit an excellent (long-term) performance.

Physical Ageing of uPVC Gas and Water Pipes

Abstract: The kinetics of physical ageing of un-plasticized P VC was investigated using Differential Scanning Calorimetry. A quantitative model was set up that describes the influence of ageing time and temperature on the well-known endothermic ageing peak. The activation energy for physical ageing of 116 kJoule/mole is very close to the literature value (115 kJoule/mole). Physical ageing of uPVC pipes leads to a decrease i n impact resistance and may ‐ for uPVC water pipes ‐ decrease the water hammer resistance. To study this, Rapid Crack Propagation measurements were performed, to assess the Critical Pressure. Crack initiation was always performed where the wall was at its thickest. Thus, RCP data was obtained with about 80% less scatter than usual. Excavated uPVC gas and water pipes have absorbed varying concentrations of water (maximum uptake 0.6 %) and carbon dioxide, which both act as plasticizer. Along with physical ageing these phenomena may affect impact performance.