Corrugated stainless-steel tubing employed for gas piping: manufacturers, sources, installation specifications & building codes. Field report of CSST gas leak. CSST gas piping protection measures.
This informative article describes CSST: carbon steel oval tube tubing used for gas piping in buildings. Since 1990 CSST has been used within many buildings both in exposed and enclosed areas to put in new gas system piping. This content discusses CSST uses, sources, installation specifications, and safety precautions to protect the gas piping from damage by abrasion, puncture, lightning strikes or other hazards. Gas piping codes and industry resources for CSST are included.
Our page top photo, provided courtesy of Carson Dunlop Associates, a Toronto home inspection & education firm, illustrates an improper installing of standard yellow CSST gas piping – routed in ground contact in a wet area. Yellow “Standard” CSST gas pipin galso requires special electrical ground bonding to minimize chance of damage & leaks in parts of high lightning strike activity.
Newer black or dark-jacketed CSST gas piping (shown below, adapted from GasTite’s FlashShield CSST sales literature) currently sold by most manufacturers might not require special bonding.
Black CSST gas piping, adapted from GasTite’s FlashShield sales literature cited in this article.
Watch out: Let’s avoid a point of confusion: CSST used as gas piping runs in buildings is just not the identical product as the flexible gas connector tubing (shown below) used to actually connect gas appliances to the gas supply system, as well as other installation and product protection measures are required. CSST gas piping is used to route natural gas or LP gas supply by way of a building as the flexible gas tubing shown below is specifically made for your connection of gas appliances towards the gas piping system.
Look for corrugated steel tubing (CSST) used as gas piping in buildings constructed in the Usa or Canada after 1990 as well as search for it in older buildings where gas piping was newly installed or modified since 1990. CSST is also set up in other countries.
Collapsing building © Daniel FriedmanStandard “yellow” or newer black CSST might be recognized in (usually) long runs involving the building gas source along with its reason for use at gas appliances. The gas appliance connector itself (shown from the photo just above) may be connected directly between your end of your CSST and the appliance, or maybe the CSST may terminate or even be combined with black iron gas piping from the same building.
CSST gas piping is run within exposed locations and through building cavities such as walls, ceilings or floors.
Just how many homes have CSST installed? We had trouble relating industry estimates with US Census data and United states Energy Information Agency data, but there is no doubt how the piping has become placed in many homes in Canada, the United States, and Japan.
In accordance with the CSST Safety Website (below), corrugated steel tubing is installed in about 500,000 new homes each and every year. As the U.S. Census Bureau and U.S. HUD February 2015 New Construction Data news release reports a seasonally adjusted annual rate of new construction within the Usa of around a million homes, that demonstrates that one half of brand new homes are increasingly being constructed with CSST gas piping.
Or if we consider the February housing start data this means that almost 100% newest homes are employing CSST gas piping – which sounds a little dubious. In 2014 the Usa EIA reported that 27% of most Usa homes were provided with gas and much less than 1% with some other gases.
I’m a dwelling contractor in Wisconsin, I might like more information on oval tube utilized for gas piping in buildings. It seems like manufacturers don’t require it to be secured or strapped significantly at all. ‘m uncertain just what the codes say with that. I’ve seen it snaked all over the place without support — and here is a story of just one consequence (quoting from a message into a manufacturer):
I wonder in the event you could supply an idea about support and protection requirements for CSST. I simply came back from helping my Brother-in-Law with a few issues in the Condo in Boston — he had a sprinkler pop within the winter, so the vast majority of drywall would have to be removed to dry things out. If the restoration contractor removed one area of drywall, the aroma of gas poured out. CSST have been snaked through floor trusses and had looped up in one location, in which a pneumatic nail through the wooden flooring installation had punctured it.
Presumably, it offers leaked considering that the building was constructed (10 years ago), and been a hazard the whole time. Any “gas” smell people might have noticed was probably masked through the smell of the garage, because the leak is in the ceiling above the garage.
Reading a few manufacturers’ installation guides, there doesn’t are most often a requirement to SECURE the gas line whatsoever — it really should be supported every 8′ or more horizontally, right? In my Brother-in-Law’s condo, the gas line was snaked throughout instead of really strapped anywhere, though it was protected by nail plates at stud and joist penetrations. Is it acceptable, as outlined by your guidelines as well as any applicable codes?
I ask, because checking this out might be covered with insurance, if it’s viewed as a hazard or otherwise not approximately code or manufacturer’s specifications. Thanks, J.
The manufacturer’s reply was essentially the CSST must be kept 3″ far from finished surfaces or protected by nail plates if also within 5″ of some constraint (similar to a penetration through a framing member). Beyond that, it offers an “escape” for nail penetrations. This did not prevent the leak I described, as the dexopky14 looped up and was hit by way of a pneumatically-driven flooring nail… CSST appears like an incredible thing — very easy to install, etc. I wonder in the event you would do a write-up on it?
The history and field experience with CSST utilize in North America generated concerns about possible pitting, corrosion or perforation of your original yellow CSST gas piping in locations where lightning strikes were common. Kraft and Torbin (2007) explained that arcing between poorly-grounded CSST gas piping and other nearby metal pathways develop a potential that could encourage electrical arcing harm to the CSST gas lines. Such lightning-related electrical arcing can weaken or even perforate the gas piping leading to dangerous gas leaks.
The risk of arcing problems for CSST is increased in places that lightning activity is greatest and where CSST is not well bonded to a grounding system.
The authors demonstrated that lightning-related electrical arcing damage risk to CSST could be reduced by direct-bonding in the gas piping system for the building’s electrical ground system: the quantity of the electrical charge from an indirect lightning strike was reduced (with their study) from 97% of the charge down to 20% by direct electrical bonding on the building’s electrical ground system. Their 2007 report concluded by using a recommendation for direct ground bonding of CSST being a proposal towards the National Fuel Gas Code. During 2009 the identical authors reported that CSST could perform acceptably but made important and detailed ideas for the soil bonding of CSST gas piping systems.
Goodson in the patent application (2009) also reported on the potency of direct bonding of both yellow and black CSST gas piping to minimize the danger of damage from indirect lightning flashing. Goodson explained that CSST was generally not much of a good electrical ground, thus lending importance towards the “direct bonding” discussion for this gas piping system. Stringfellow (2013) continued to report on electrically-induced gas distribution piping.
Currently (2015) the manufacturers have virtually switched for an improved, stronger CSST gas piping whose design incorporates a protective outer jacket and then for which extra manufacturer-specified ground bonding is not required. I feel that only Ward is constantly make the yellow CSST accessible in the United states
In accordance with Jim Narva, executive director from the National Association of State Fire Marshals, that association is concentrating on informing homeowners of the demand for retrofit ground bonding of older CSST installations.
OPINION: I agree that CSST needs to be protected from damage, including or maybe particularly when it is run through building cavities where, hidden from view, it’s otherwise too feasible for a future building occupant or worker to shoot a nail or screw throughout the material. One could assume that excluding concerns for corrosion, similar worries pertain to (and customarily prohibit the application of) flexible copper tubing when used for gas piping: it is not necessarily routed within building cavities. Instead in those situations it’s common to use steel piping for such gas lines.
Inside the CSST installation example specifications listed below you’ll see that the manufacturers typically require a variety of installation details to make sure safe reliable operation of the gas piping system, including nail plates, flexible corrugated steel armor in a few locations, support, and other measures. Some local jurisdictions further detail CSST gas piping installation specifications including how and where it might be routed.
Below at left is an illustration of a conventional steel gas pipe routed via a wall cavity during building renovations of your Ny Home. As well as below right you will see the conventional differ from flexible copper tubing to stainless steel gas pipe if the gas piping system were required to penetrate your building wall.