Reported incidents of fires resulting from lightning strikes near structures containing corrugated stainless steel gas piping have resulted in a debate within both the lightning protection and CSST industries about the level of risk associated with the use of CSST.
CSST consists of a continuous, flexible, stainless steel pipe with an exterior PVC covering. More than 150 million feet has been installed in residential, commercial and industrial structures since 1989.
According to representatives of the lightning protection industry, the relative thinness of CSST tubing compared to black iron, copper or aluminum gas pipes presents an unknown risk of the effects of a lighting strike on or near structures.
The lightning protection industry says it has noted some issues related to fire damage caused by lightning strikes affecting CSST systems, but does not currently have adequate data to provide definitive answers, according to Jennifer Morgan, a lightning safety education coordinator with the Lightning Safety Alliance.
“We're not sure how big a problem it is. No research was done on CSST and how it relates to fire before (CSST) went into the market,” Morgan said.
The manufacturers of CSST, including industry-leading Omega Flex Inc., strongly refute the warnings issued by the Lightning Safety Alliance. Their products present no greater risk than alternative gas piping materials, according to Kevin Hoben, president and CEO of Omega Flex.
“This product has been on the U.S. market since 1989. No one has been able to attribute a death or an injury to lightning strikes affecting CSST. We would not be in business if the product was vulnerable to lightning,” Hoben said.
Major manufactures of CSST include Omega Flex, Parker-Hannifin Corp., Titeflex Corp. and Ward Manufacturing Inc. All four were included in a class action lawsuit filed in the Circuit Court of Clark County, Ark.
A settlement was reached in March 2007 that made vouchers available for owners of structures containing CSST to pay for lightning protection systems and/or make bonding and grounding connections to certain systems in the structure. The deadline for property owners to enter a claim under the settlement passed in September 2007.
Hoben said Omega Flex was forced by the class action lawsuit to conduct both internal and independent research on the fire risk to structures with CSST resulting from nearby lightning strikes.
“We submitted our entire research history to the Consumer Product Safety Commission in Washington, D.C. Their conclusion was our product was safe, and they didn't want to do any further research or action on the product,” Hoben said.
According to Mitchell Guthrie, an independent lightning protection consultant based in North Carolina, the thinness of CSST walls and its ability to hold up against a lightning strike are of interest to lightning protection experts.
“There is a question of the additional sensitivity of CSST, which might require other bonding above and beyond the current standard,” Guthrie said.
Complicating the issue of proper bonding/grounding for CSST piping is the lack of knowledge by both the lighting protection industry and mechanical contractors.
“I've talked to a couple of mechanical contractors, and they were completely unfamiliar with the lighting issue. They indicated that there wasn't a rigorous training procedure (for installation),” Morgan said.
Omega Flex said its installation manual calls for installers to make a direct bond between its TRACPIPE product and a structure's electrical system, according to Hoben. Neither Morgan nor Guthrie would go so far as to call CSST dangerous. Guthrie acknowledged that CSST's lower overall cost and “flexibility to be put anywhere,” make it an attractive alternative to traditional gas tubing.
“I wouldn't go to the extent that CSST is unsafe. Without an arc, I don't think it's dangerous,” Guthrie said. “In my personal point of view, though, there are certainly some concerns. The wall thickness is much less than other types of tubing.”
Omega Flex's Hoben dismissed the lightning industry's position.
“A recognized standard, ANSI LC-1, controls the whole protocol of the manufacture, testing and installation of CSST. It was the only one of three gas-piping materials (the others being black-iron and copper) that was developed to an approved standard. In the early 2000s, it had surpassed black-iron as the preferred piping material in the United States,” Hoben said.
Mark Albino, chief operating officer of Omega Flex, said the lightning protection industry is exaggerating the risk of fires caused by lightning-strike energized CSST piping. Albino cited average annual figures from 2000 to 2004 provided by the National Fire Protection Association that show “a very small fraction” of residential fires in the U.S. are caused by lightning strikes.