Plastic pipe with structure having improved critical pressure

摘要

A pipe for fluid transportation is made up of a first layer of material with a first desired critical pressure PC1 and a second layer of material with a critical pressure PC2<0.4PC1. Thickness of the first layer is between 0.1% and 25% of total pipe thickness but not less than 0.3 mm and preferably 0.5-1 mm). Surprising it is observed that a pipe made in this manner has a critical pressure CP near the first desired critical pressure PC1 despite the low thickness of the first layer.