Polyethylene (PE) plastic pipe and fittings are the main materials currently used in new medium- and low-pressure natural gas distribution systems and to repair older steel and cast iron systems. While PE has many advantages over steel in terms of corrosion resistance and ductility, its use nonetheless carries risk, especially near joints.
As with steel, joining of PE pipe and fittings requires skilled workers following verified procedures. Unlike steel, PE under stress is known to have finite life as an unavoidable result of polymer physics. Accordingly, it is a fundamental design principle that the finite life must far exceed any reasonably anticipated service lifetime
Polyethylene pipes and fittings are widely utilized for gas (and water) distribution. Maintaining their integrity is critical to long-term use without incident. It is important to not only ensure that new products are fit for their intended use, but also to understand the effect of environmental factors during installation and use. We have found that contamination with compounds such as bentonite-based clay that is commonly used in horizontal-directional drilling mud can prevent effective joint fusion, potentially creating leaks with adverse ramifications.