Leevers, Henderson, Pereira
# 2006 Washington DC
Laboratory-scale S4 tests have been used to determine whether it would be possible, at any realistic working pressure, for a loosely-fitted PE liner within a rigid host pipe to fail by Rapid Crack Propagation (RCP). The standard ISO 13477 S4 method was modified by replacement of the containment ring cage by a rigid, closed sleeve having one of three predefined clearances. 125 mm SDR 11 and SDR 17.6 PE80 pipe at 0°C — within which RCP is normally possible — was tested within three rigid containments of different gap sizes, as well as with the usual S4 containment cage. For pipe having an unpressurised clearance down to 2% or so of the diameter, the RCP critical pressure was increased by about 50% for both SDRs; for smaller clearances, by progressively more.