Corrugated stainless-steel tubing utilized for gas piping: manufacturers, sources, installation specifications & building codes. Field report of CSST gas leak. CSST gas piping protection measures.
This short article describes CSST: corrugated steel pipe tubing useful for gas piping in buildings. Since 1990 CSST has been used within many buildings in both exposed and enclosed areas to put in new gas system piping. The content discusses CSST uses, sources, installation specifications, and security measures to guard the gas piping from damage by abrasion, puncture, lightning strikes or other hazards. Gas piping codes and industry causes of CSST are included.
Our page top photo, provided courtesy of Carson Dunlop Associates, a Toronto home inspection & education firm, illustrates an improper installation of standard yellow CSST gas piping – routed in ground contact within a wet area. Yellow “Standard” CSST gas pipin galso requires special electrical ground bonding to reduce probability 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 may not require special bonding.
Black CSST gas piping, adapted from GasTite’s FlashShield sales literature cited on this page.
Watch out: Let’s avoid a reason for confusion: CSST used as gas piping runs in buildings is not really exactly the same product as being the flexible gas connector tubing (shown below) accustomed to actually connect gas appliances towards the gas supply system, and different installation and product protection measures are essential. CSST gas piping can be used to route gas or LP gas supply using a building even though the flexible gas tubing shown below is specifically designed for your connection of gas appliances for the gas piping system.
Search for corrugated stainless-steel tubing (CSST) used as gas piping in buildings constructed in the Usa or Canada after 1990 as well as try to find it in older buildings where gas piping was newly installed or modified since 1990. CSST is additionally placed in other countries.
Collapsing building © Daniel FriedmanStandard “yellow” or newer black CSST can be recognized in (usually) long runs between your building gas source and its point of use at gas appliances. The gas appliance connector itself (shown within the photo just above) could be connected directly involving the end of the CSST and also the appliance, or the CSST may terminate or even be combined with black iron gas piping from the same building.
CSST gas piping is run both in exposed locations and thru building cavities like walls, ceilings or floors.
The amount of homes have CSST installed? We had trouble relating industry estimates along with us Census data and U.S. Energy Information Agency data, but there is no doubt that this piping has become positioned in many homes in Canada, the us, and Japan.
In line with the CSST Safety Website (below), corrugated stainless steel tubing is placed in about 500,000 new homes each year. As being the U.S. Census Bureau and Usa HUD February 2015 New Construction Data news release reports a seasonally adjusted annual rate newest construction in the Usa of about a million homes, that shows that 50 % of brand-new homes are increasingly being constructed with CSST gas piping.
Or maybe we consider the February housing start data this means that almost 100% of the latest homes use CSST gas piping – which sounds somewhat dubious. In 2014 the U.S. EIA reported that 27% of Usa homes were supplied with gas and much less than 1% with other gases.
I’m a dwelling contractor in Wisconsin, I might like more details on steel oval tube utilized for gas piping in buildings. It appears as though manufacturers don’t require that it is secured or strapped very much in any way. ‘m not sure what the codes say concerning this. I’ve seen it snaked almost everywhere without support — and here is a story of a single consequence (quoting from an e-mail to your manufacturer):
I wonder if you could produce an idea about support and protection requirements for CSST. I really came back from helping my Brother-in-Law with just a few issues within his Condo in Boston — he experienced a sprinkler pop within the winter, so the vast majority of drywall needed to be removed to dry things out. As soon as the restoration contractor removed one area of drywall, the aroma of gas poured out. CSST was snaked through floor trusses and had looped up in a location, in which a pneumatic nail through the wood flooring installation had punctured it.
Presumably, they have leaked since the building was constructed (ten years ago), and been a hazard the entire time. Any “gas” smell people may have noticed was probably masked from the smell of the garage, since the leak is at the ceiling over the garage.
Reading several manufacturers’ installation guides, there doesn’t seem to be a requirement to SECURE the gas line in any way — it really has to be supported every 8′ approximately horizontally, right? Inside my Brother-in-Law’s condo, the gas line was snaked throughout and never really strapped anywhere, although it was protected by nail plates at stud and joist penetrations. Is it acceptable, as outlined by your guidelines as well as applicable codes?
I ask, because checking this out might be covered with insurance, if it’s viewed as a hazard or otherwise not as much as code or manufacturer’s specifications. Thanks, J.
The manufacturer’s reply was essentially that the CSST must be kept 3″ from finished surfaces or protected by nail plates if also within 5″ of some constraint (similar to a penetration by way of a framing member). Beyond that, they have an “escape” for nail penetrations. This did not stop the leak I described, because the dexopky14 looped up and was hit with a pneumatically-driven flooring nail… CSST looks like an incredible thing — an easy task to install, etc. I wonder should you would do articles into it?
A brief history and field experience of CSST use in The United States triggered concerns about possible pitting, corrosion or perforation in the original yellow CSST gas piping in places that lightning strikes were common. Kraft and Torbin (2007) explained that arcing between poorly-grounded CSST gas piping and also other nearby metal pathways develop a potential that could encourage electrical arcing damage to the CSST gas lines. Such lightning-related electrical arcing can weaken as well as perforate the gas piping leading to dangerous gas leaks.
The danger of arcing problems for CSST is increased in areas where lightning activity is greatest and where the CSST will not be well bonded to a grounding system.
The authors demonstrated that lightning-related electrical arcing damage risk to CSST could be reduced by direct-bonding from the gas piping system towards the building’s electrical ground system: the degree of the electrical charge from an indirect lightning strike was reduced (with their study) from 97% of your charge right down to 20% by direct electrical bonding for the building’s electrical ground system. Their 2007 report concluded using a recommendation for direct ground bonding of CSST like a proposal for the National Fuel Gas Code. In 2009 the identical authors reported that CSST could perform acceptably but made important and detailed strategies for the floor bonding of CSST gas piping systems.
Goodson in the patent application (2009) also reported on the effectiveness of direct bonding of both yellow and black CSST gas piping to reduce the risk of damage from indirect lightning flashing. Goodson explained that CSST was generally not a good electrical ground, thus lending importance on the “direct bonding” discussion for this particular gas piping system. Stringfellow (2013) continued to report on electrically-induced gas distribution piping.
Currently (2015) the manufacturers have pretty much switched to a improved, more durable CSST gas piping whose design contains a protective outer jacket and for which extra manufacturer-specified ground bonding is not required. I believe that only Ward continues to make the yellow CSST easily obtainable in the United states
According to Jim Narva, executive director in the National Association of State Fire Marshals, that association is concentrating on informing homeowners of the necessity for retrofit ground bonding of older CSST installations.
OPINION: I agree that CSST must be protected from damage, including or maybe especially 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 from the material. One could feel that excluding concerns for corrosion, similar worries relate to (and customarily prohibit using) flexible copper tubing when employed for gas piping: it is far from routed within building cavities. Instead in those situations it’s present with use steel piping for such gas lines.
Inside the CSST installation example specifications shown below you’ll realize that the makers typically require several installation details to assure safe reliable operation of your gas piping system, including nail plates, flexible corrugated steel armor in a few locations, support, and also other measures. Some local jurisdictions further detail CSST gas piping installation specifications for example where and how it can be routed.
Below at left is an illustration of this a regular steel gas pipe routed by way of a wall cavity during building renovations of your Ny Home. As well as below right you will notice the traditional vary from flexible copper tubing to corrugated stainless steel pipe when the gas piping system was required to penetrate the property wall.