It is two o’clock in the morning. A thunderstorm crackles in the distance, providing the perfect weather for a deep sleep. That is, unless your business or home contains a building product known as corrugated stainless steel tubing.
At a moment’s notice, a gas-fed blaze may destroy your property.
This scenario is all too common, yet the general public has little knowledge of the destructive nature of CSST when exposed to the foreseeable effects of lightning.
CSST is a flexible fuel gas tubing system that was intended to replace black iron pipe as a means of transporting natural and propane gas from the meter outside of a structure to the various appliances and machinery fueled by gas.
In the competitive marketplace of residential and commercial construction, CSST offered a favorable alternative to black iron pipe at first blush, as it is less labor intensive to install. The primary defect with CSST is that the wall thickness of the product is too thin to withstand the electrical energy dissipated by lightning strikes.
In terms of approximate wall thickness, CSST measures a mere .011 inches, while black iron pipe measures .113 inches—10 times thicker. This characteristic is common to all CSST and is not limited to a single brand.
Without question, a direct lightning strike has the potential to cause severe damage to any structure. However, an indirect strike is far more common and, until the advent of CSST, was not commonly associated with fires.
When a lightning strike occurs, a tremendous amount of electrical energy travels through the earth in an unpredictable manner. The energy can enter a structure through any conductive path, such as a water main, gas piping or utility wiring. For a microsecond, this energy travels through the property, until the electricity is able to reach ground.
With black iron pipe, this surge of energy presents no problem, as the wall thickness of the iron pipe allows it to absorb such energy without failure. However, CSST is incapable of withstanding such energy, which consequently seeks to arc to other metal surfaces (pipes, duct work) in the structure.
When an electrical arc occurs, a small hole is created in the CSST and pressurized natural gas escapes. This gas is instantaneously ignited by the heat of the event and the result is a blow torch flame reaching lengths of three-to-four feet with an unlimited supply of fuel.
How is it that CSST was installed in structures throughout the United States without knowledge of this potential hazard?
When CSST was brought to the United States in the late 1990s, performance evaluations were conducted and CSST passed various tests relating to the product’s corrosive resistance and ability to withstand pressure, as well as its bending capabilities. However, there never was any consideration given to the energy from lightning because there has never been a reported failure of black iron pipe under these circumstances.
In fact, the National Electric Code and National Fuel Gas Code contain no guidance for the protection of gas systems from lightning energy because these systems enjoyed the historically safe protection of black iron pipe which, over a period of more than 100 years of continuous use, has proven itself to be impervious to such electrical insults.
Empirical studies from experts estimate that CSST is over one million times more likely to fail than black iron pipe when exposed to the energy from indirect lightning.
According to certain CSST manufacturers, when properly bonded to the building electrical systems, the CSST is capable of withstanding the energy produced by indirect lightning. However, bonding, which is the permanent joinder of metallic parts to form an electrically conductive path, has never been tested under laboratory or field conditions by the CSST manufacturers or installers to demonstrate its effectiveness in protecting CSST from lightning, or so they claim.
Indeed, the National Fire Protection Association has taken notice of the numerous fires caused by CSST and has formed a technical committee to study the issue. The goal of the committee is to determine whether CSST can be safe.
As of June 2010, the technical committee reported receiving information of “limited value” from the CSST industry as a whole regarding the effectiveness of bonding. As a result, the committee is considering an all-out prohibition on the installation of CSST to be issued in the next version of the National Fuel Gas Code, due for publication in 2014.
Literally hundreds of residential and commercial fires have occurred as a result of the catastrophic failure of CSST. These fires have given rise to a number of lawsuits filed against the individual CSST manufacturers, as well as the installation and general contractors.
In the first case tried to a verdict in October 2010, a Chester County, Pa. jury found the CSST product was defective, awarding 100 percent of claimed damages exceeding $1 million.
The case, which was brought by a pair of homeowners and their insurer, involved a residential fire that occurred in June of 2007. The homeowners’ entire residence and their personal belongings were destroyed after an indirect lightning strike energized the bonded CSST system in the home. The verdict came after an eight-day trial.
CSST failures are annually responsible for millions of dollars in property damage across the United States, and hundreds of claims are pending against the various manufacturers of CSST.