Volume 8, Issue 7 (July 2011)
Environmental Stress Cracking of Commercial CPVC Pipes
A study has been made by the author to learn effects of single and of mixed glycols causing environmental stress cracking of CPVC pipes made by four different manufacturers from two different resin suppliers. The study has shown that a mixture of ethylene glycol and propylene glycol is more damaging to CPVC pipe than either of the glycols by itself in the same relative concentration in water. The study also showed that one pipe resin containing a “tail” of lower molecular weight resin is somewhat more susceptible to cracking than the other resin. A secondary study also shows that the test method is appropriate for quickly evaluating chemicals in anti-corrosion treatments on steel pipes in sprinkler systems that can be particularly damaging to CPVC pipe.