Abstract:

A leak tightness experiment was performed for the steel-plastic-transition joint parts with different structures after tensile tests. The results indicated that that wall thickness of the joint parts had an influence on the leak tightness between the steel and high-density polyethylene （PE-HD） after tensile loading. When the wall thickness in the PE-HD part became smaller， the joint was more easily subject to yielding， pulling-out， rupture， or leakage. Meanwhile， the low?height anti-pulling-out gear structure of the steel part was more easily subject to pulling-out and leakage on the transitions with larger sizes. The transitions made from injection?molded PE-HD parts or PE?HD pipe segments with higher standard dimension ratios were found to exhibit better performance than those made from common PE?HD pipe segments. The first two types had higher safety margins and better stability at a low temperature and under the creeping process of PE?HD with extreme circumstances.

Key words: high density polyethylene, steel-plastic-transition, leak tightness, pipe