Abstract
Results are presented from an international collaboration project called EVOPE. The aim of the work was to develop a lifetime model for PE-gas pipes. The lifetime of a plastic pipe depends on material, environmental and loading factors. Plastic pipes are exposed to chemical and mechanical degradation. The EVOPE project deals with the mechanical failure mechanisms exclusively since chemical degradation is not a matter of concern during normal service conditions. According to field failure statistics from France and the United States, 84% of all field failures occurred in welds in PE-gas pipes. In general rapid crack propagation is favoured by large pipe diameters, large wall thickness, low temperature and high internal overpressure. Slow crack growth (SCG) is the predominant failure mechanism for brittle long term failures. The SCG-testing with notched specimens was done using dead loaded notched specimens or notched pipe specimens with a constant internal overpressure. Data show that SCG testing with notched specimens reduces the time to brittle failure twenty times compared to hydrostatic pressure testing of un-notched pipes if the specimens are not chemically degraded during testing. Lifetime estimation was possible within a testing time of 30-6000 h (depending on the pipe material) by using SCG-testing at 80
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Citation Formats
Traenkner, T, and Ifwarson, M.
EVOPE - Evaluation of polyethylene pipes for gas distribution. Final report; EVOPE - Utvaerdering av polyetenroer foer gasdistribution. Slutrapport.
Sweden: N. p.,
1994.
Web.
Traenkner, T, & Ifwarson, M.
EVOPE - Evaluation of polyethylene pipes for gas distribution. Final report; EVOPE - Utvaerdering av polyetenroer foer gasdistribution. Slutrapport.
Sweden.
Traenkner, T, and Ifwarson, M.
1994.
"EVOPE - Evaluation of polyethylene pipes for gas distribution. Final report; EVOPE - Utvaerdering av polyetenroer foer gasdistribution. Slutrapport."
Sweden.
@misc{etde_10114446,
title = {EVOPE - Evaluation of polyethylene pipes for gas distribution. Final report; EVOPE - Utvaerdering av polyetenroer foer gasdistribution. Slutrapport}
author = {Traenkner, T, and Ifwarson, M}
abstractNote = {Results are presented from an international collaboration project called EVOPE. The aim of the work was to develop a lifetime model for PE-gas pipes. The lifetime of a plastic pipe depends on material, environmental and loading factors. Plastic pipes are exposed to chemical and mechanical degradation. The EVOPE project deals with the mechanical failure mechanisms exclusively since chemical degradation is not a matter of concern during normal service conditions. According to field failure statistics from France and the United States, 84% of all field failures occurred in welds in PE-gas pipes. In general rapid crack propagation is favoured by large pipe diameters, large wall thickness, low temperature and high internal overpressure. Slow crack growth (SCG) is the predominant failure mechanism for brittle long term failures. The SCG-testing with notched specimens was done using dead loaded notched specimens or notched pipe specimens with a constant internal overpressure. Data show that SCG testing with notched specimens reduces the time to brittle failure twenty times compared to hydrostatic pressure testing of un-notched pipes if the specimens are not chemically degraded during testing. Lifetime estimation was possible within a testing time of 30-6000 h (depending on the pipe material) by using SCG-testing at 80 degrees C in air. Of the three resins investigated within EVOPE the Swedish gas pipe material had the longest failure time at 80 degrees C in air. SCG testing is a good method for lifetime estimation and ranking of different PE-materials. 19 refs, 18 figs, 8 tabs}
place = {Sweden}
year = {1994}
month = {May}
}
title = {EVOPE - Evaluation of polyethylene pipes for gas distribution. Final report; EVOPE - Utvaerdering av polyetenroer foer gasdistribution. Slutrapport}
author = {Traenkner, T, and Ifwarson, M}
abstractNote = {Results are presented from an international collaboration project called EVOPE. The aim of the work was to develop a lifetime model for PE-gas pipes. The lifetime of a plastic pipe depends on material, environmental and loading factors. Plastic pipes are exposed to chemical and mechanical degradation. The EVOPE project deals with the mechanical failure mechanisms exclusively since chemical degradation is not a matter of concern during normal service conditions. According to field failure statistics from France and the United States, 84% of all field failures occurred in welds in PE-gas pipes. In general rapid crack propagation is favoured by large pipe diameters, large wall thickness, low temperature and high internal overpressure. Slow crack growth (SCG) is the predominant failure mechanism for brittle long term failures. The SCG-testing with notched specimens was done using dead loaded notched specimens or notched pipe specimens with a constant internal overpressure. Data show that SCG testing with notched specimens reduces the time to brittle failure twenty times compared to hydrostatic pressure testing of un-notched pipes if the specimens are not chemically degraded during testing. Lifetime estimation was possible within a testing time of 30-6000 h (depending on the pipe material) by using SCG-testing at 80 degrees C in air. Of the three resins investigated within EVOPE the Swedish gas pipe material had the longest failure time at 80 degrees C in air. SCG testing is a good method for lifetime estimation and ranking of different PE-materials. 19 refs, 18 figs, 8 tabs}
place = {Sweden}
year = {1994}
month = {May}
}