Submitted by Rodney Twyford, NPI Franchise Owner, San Antonio, Texas
For decades, rigid schedule 40 black iron pipe was the most popular choice for natural gas distribution to appliances such as furnaces and water heaters in both residential and commercial buildings. Iron pipe is known for its durability; however, due to the numerous threaded joints that occur at each intersection during installation, it is also prone to leaks as a result of poor installation or failed joint compound. The rigid iron pipe has also been known to break and/or become distorted as a result of structural movement in the event of an earthquake or other significant damage to structures.
Corrugated stainless steel tubing (CSST) is a flexible gas pipe that was first developed in Japan and used to supply and distribute natural gas or propane gas in residential and commercial buildings. According to some manufacturers, it was developed to solve the dangers of broken rigid gas piping in earthquakes, and then brought to the United States by American Gas Association and the Gas Research Institute as an alternative gas piping solution to eliminate the difficulties and dangers of rigid gas piping. The cost of CSST is higher than iron pipe; however, due to the ease of installation, the labor cost is much lower, making it more cost effective to install.
The yellow version of CSST was introduced to the United States around 1988 and has become the preferred and most widely used gas piping product among construction trades. However, due to its inability to effectively resist or withstand the electrical charge produced by a direct or indirect lightning strike, it could be pierced by an arc during electrical storms, causing stimulated fires to occur.
Yellow CSST has been blamed for causing stimulated fires in more than 140 homes involving lightning strikes, some of which have resulted in death, and has been banned by local authorities in some areas. The CSST is approximately 10 times thinner than the traditional black iron gas pipe used for many years. Studies have shown that high voltage produced by lightning strikes can cause metal components to arc, resulting in perforation of the thin CSST wall and therefore cause gas to leak, resulting in fuel-fed fires.
Whether you are building a new home or buying an existing property, it is recommended to consult a licensed electrician who is familiar with CSST piping and the current codes governing the proper installation, including specific bonding requirements. Code enforcement organizations, such as the National Fuel Gas Code, National Fire Protection Association and National Electric Code are constantly improving the standards for proper installation of building materials, but even when CSST is properly installed per current code requirements, it is not guaranteed to resist damage caused by a direct or indirect lightning strike.
A new type of CSST has hit the market and can be recognized by a black coating and branded as Counter Strike, Omega Flex, Trace Pipe or Flash Shield. The black CSST product is constructed with a continuous bond between the tubing and a black jacket that helps protect the product. Studies have shown black-jacketed CSST to be more resistant to the effects of an indirect lightning strike; however, due to the unpredictable, violent nature of lightning, there are no guarantees that it will be unharmed in the event of an electrical storm. Some manufacturers of the black-jacketed CSST products claim that no additional bonding is required. However, local and/or international codes governing building construction are controlling and may differ from the manufacturer’s requirements.
To learn more about CSST visit, http://www.CSSTSafety.com.