Plastic Pipes Conference Association # 2010 Vancouver
E.Nezbedova
The service life for HDPE (PE 80, PE 100) materials used in plastic pipes application covers a time span of up 50 years. The new type of PE 100 (PE 100 RC) should achieve the life time over 100 years. Conventional hydrostatic pressure test to qualify a new resin must last 104 hours (ISO 1167). In the last twenty years two accelerated tests that produce the same type of brittle fracture that occurs in pipes after long time in service were developed and standardized (PENT and FNCT tests). In contrast to FNCT, PENT enables to follow the kinetics of slow crack growth (SCG) and estimates some relevant parameters (time for SCG initiation, rate of SCG and time to failure). These experimentally data, which can be described by exponential relationship in combination with numerical simulation of slow crack growth enable to described the part of time to rupture curve that is responsible for service lifetime. This procedure can substitute time consuming and expensive testing.
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