Electric Arc Holes in Corrugated Stainless Steel Tubing

Corrugated stainless steel tubing (CSST) has become a common product installed in new and retrofitted older homes. The ease of installation due to its flexibility and the need for fewer joints significantly lowers labor costs. Despite the advantages of lower cost and ease of installation, however, the thin wall of CSST presents an increased risk of perforation by both mechanical puncturing and electrical arcing from either household current or lightning strikes. In the course of forensic investigations of household fires, perforated tubing is occasionally identified as a potential cause. The metallurgical features of the perforated area are capable of distinguishing the cause of the hole as being from either lightning current or household current.