CSST History
 

QUESTION: What is CSST?
ANSWER: Corrugated Stainless Steel Tubing (CSST) is a flexible, stainless steel pipe used to supply natural gas and propane in residential, commercial and industrial structures. (back to top)
QUESTION: What does CSST look like?
ANSWER: CSST is often coated with a yellow, or in some cases, a black exterior plastic coating. CSST should NOT be confused with flexible gas appliance connectors - the product that joins a moveable appliance to your home or building's gas supply line. (back to top)
QUESTION: What are the benefits of flexible gas piping?
ANSWER: Besides providing greater durability, CSST is flexible, allowing it to be snaked around walls and through obstacles with fittings needed only at the ends of each run. Reducing the number of fittings is beneficial as each additional joint needs to be fitted and checked for leaks. A CSST gas piping system has less joints, and therefore less potential leak paths. (back to top)
QUESTION: When was CSST first introduced into homes?
ANSWER: CSST was first introduced in Japan in the 1980s. It was introduced in the U.S. in 1990. (back to top)
QUESTION: How many homes have CSST?
ANSWER: In the U.S., about 500,000 new homes per year have CSST installed; that number is about half of the number of new homes built each year that use gas for heating and cooking. As of 2012, about seven million homes in the U.S. had CSST installed. Since 1989, approximately one billion feet has been in stalled in residential, commercial, and industrial structures. (back to top)
QUESTION: Where is CSST located in my home?
ANSWER: CSST is usually routed beneath, through and alongside floor joists in your basement, inside interior wall cavities and on top of ceiling joists in attic spaces or connected to fixed appliances such as water heaters. (back to top)
QUESTION: Is CSST safe to use in my home?
ANSWER: Like all approved gas piping systems, CSST is safe when properly installed. CSST must be installed by a qualified professional and in accordance with the Manufacturer's Design and Installation (D&I) Guide, including bonding and grounding of the system. (back to top)
QUESTION: What are the effects of lightning on CSST?
ANSWER: Lightning is a highly destructive force. Even a nearby lightning strike that does not strike a structure directly can cause systems in the structure to become electrically energized. This power surge can potentially puncture a hole in CSST and cause a fire. (back to top)
QUESTION: How many homes are struck by lightning every year?

ANSWER: Lightning causes 7,216 house fires every year, according to the U.S. Fire Administration.

  Additional information:        
  U.S. house fires per year 253,500   NFPA Oct 2009  
  Housing units in the U.S.  129,925,421   U.S. Census Aug 2010  
  Lightning strikes per year  22,000,000   NOAA Aug 2010  
  Lightning related insurance claims in 2009 185,789   III June 2010  

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QUESTION: Which states have a high lightning risk?
ANSWER: All states have lightning activity and associated risks. Click here to view a map illustrating the areas where lightning strikes occur most frequently. (back to top)
QUESTION: If I have CSST in my home, what do I do and who do I call?
ANSWER: If you have CSST in your home or business you should determine if the fuel gas piping system is bonded and grounded. This requirement will include the attachment of a listed bonding clamp (click for picture) and bonding wire to the gas piping system. For assistance with this, please consult with a licensed electrician who can perform the inspection and upgrade per the CSST Direct Bonding Tech Bulletin. (back to top)
QUESTION: What is bonding and grounding?
ANSWER: Bonding: Connecting metallic systems to establish electrical continuity and conductivity.
Grounding: Connecting to the ground or to a conductive body that extends to ground connection.
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QUESTION: Why is it important to bond and ground my CSST?
ANSWER: Bonding is provided primarily to prevent a possible electric shock to people who come in contact with the gas piping and other metal objects connected to the grounding system. Nearby lightning strikes can result in an electrical surge that can potentially puncture a hole in CSST and cause a fire. Proper bonding and grounding will reduce the risk of damage and fire from a lightning strike. (back to top)
QUESTION: Who is recommended to perform this work?
ANSWER: Bonding is considered electrical work so it is recommended that a licensed electrician is contacted to inspect or perform any electrical bonding work. (back to top)
QUESTION: What information do I need to provide to my electrician?
ANSWER: Information to provide an electrician can be found in the CSST Direct Bonding Tech Bulletin (click to view and print PDF).(back to top)
QUESTION: What is the difference between CSST and flexible gas appliance connectors?
ANSWER: CSST should NOT be confused with flexible gas appliance connectors – the product that joins a moveable appliance to your home or building's gas supply line. The difference is flexible connectors attach directly to the moveable appliance from the wall or floor. CSST is usually routed beneath, through and alongside floor joists in your basement, inside interior wall cavities and on top of ceiling joists in attic spaces. (back to top)
QUESTION: What do I need to know about current building codes?
ANSWER: U.S. model building codes currently require direct bonding of CSST. They did not require this prior to 2009, and that is why there are many homes in the U.S. where CSST is not installed to current model code requirements, that can benefit from the bonding and grounding upgrade.
Reference 2009 NFPA 54 National Fuel Gas Code, sec. 7.13.2, and 2011 NFPA 70 National Electric Code, sec. 250.104 Informational Notes No. 2.
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QUESTION: What is the current fuel gas code?
ANSWER: NFPA 54 National Fuel Gas Code. Sec 7.13.2 specifies the CSST bonding requirement. (back to top)
QUESTION: If I would like to contact the manufacturer regarding questions or concerns, how do I determine which manufacturer/product was used?
ANSWER: The name of the manufacturer/product is listed on the tubing every three feet. (back to top)