Corrugated steel tubing utilized for gas piping: manufacturers, sources, installation specifications & building codes. Field report of CSST gas leak. CSST gas piping protection measures.
This article describes CSST: corrugated steel pipe tubing utilized for gas piping in buildings. Since 1990 CSST has been utilized within many buildings in both exposed and enclosed areas to put in new gas system piping. This content discusses CSST uses, sources, installation specifications, and safety measures to guard the gas piping from damage by abrasion, puncture, lightning strikes or any 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 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 post.
Watch out: Let’s avoid a reason for confusion: CSST used as gas piping runs in buildings is not exactly the same product as being the flexible gas connector tubing (shown below) employed to actually connect gas appliances towards the gas supply system, and different installation and product protection measures will be required. CSST gas piping is utilized to route gas or LP gas supply by way of a building as the flexible gas tubing shown below is specifically designed for your connection of gas appliances for the gas piping system.
Look for corrugated stainless tubing (CSST) used as gas piping in buildings constructed within the Usa or Canada after 1990 and in addition seek out it in older buildings where gas piping was newly installed or modified since 1990. CSST is also positioned in other countries.
Collapsing building © Daniel FriedmanStandard “yellow” or newer black CSST can be recognized in (usually) long runs in between the building gas source as well as 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 from the CSST and also the appliance, or maybe the CSST may terminate or perhaps be blended with black iron gas piping within the same building.
CSST gas piping is run within exposed locations and thru building cavities like walls, ceilings or floors.
The number of homes have CSST installed? We had trouble relating industry estimates along with us Census data and Usa Energy Information Agency data, but it is obvious that this piping has been set up in many homes in Canada, the usa, and Japan.
In accordance with the CSST Safety Website (below), corrugated stainless tubing is set up in about 500,000 new homes each year. Since the United states Census Bureau and U.S. HUD February 2015 New Construction Data news release reports a seasonally adjusted annual rate of the latest construction in the Usa of about 1 million homes, that demonstrates that 1 / 2 of all new homes are created with CSST gas piping.
Or maybe if we consider the February housing start data this means that almost 100% newest homes are using CSST gas piping – which sounds a lttle bit dubious. In 2014 the U.S. EIA reported that 27% of all the United states homes were supplied with natural gas and much less than 1% along with other gases.
I’m a dwelling contractor in Wisconsin, I would personally like more information on elliptical tube used for gas piping in buildings. It seems like manufacturers don’t require that it is secured or strapped significantly in any way. ‘m unsure exactly what the codes say concerning this. I’ve seen it snaked everywhere without support — and listed here is a story of just one consequence (quoting from an email to some manufacturer):
I wonder if you could supply a concept about support and protection requirements for CSST. I recently came back from helping my Brother-in-Law with some issues in the Condo in Boston — he possessed a sprinkler pop on the winter, so many of the drywall had to be removed to dry things out. As soon as the restoration contractor removed one area of drywall, the smell of gas poured out. CSST ended up being snaked through floor trusses and had looped up in just one location, when a pneumatic nail through the hardwood flooring installation had punctured it.
Presumably, it provides leaked since the building was constructed (ten years ago), and been a hazard the entire time. Any “gas” smell people could have noticed was probably masked through the smell of the garage, because the leak was in the ceiling on top of the garage.
Reading a couple of manufacturers’ installation guides, there doesn’t are most often a requirement to SECURE the gas line by any means — it simply should be supported every 8′ or more horizontally, right? During 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. Could this be acceptable, as outlined by your guidelines and any applicable codes?
I ask, because checking this out could be covered by insurance, if it’s seen as a hazard or not approximately code or manufacturer’s specifications. Thanks, J.
The manufacturer’s reply was essentially that this CSST should be kept 3″ far from finished surfaces or protected by nail plates if also within 5″ of some constraint (just like a penetration using a framing member). Beyond that, they have an “escape” for nail penetrations. This failed to avoid the leak I described, since the dexopky14 looped up and was hit from a pneumatically-driven flooring nail… CSST may seem like a fantastic thing — very easy to install, etc. I wonder if you would do a post into it?
The historical past and field experience of CSST utilization in North America triggered concerns about possible pitting, corrosion or perforation from 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 as well as other nearby metal pathways create 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 ultimately causing dangerous gas leaks.
The risk of arcing damage to CSST is increased in areas where lightning activity is greatest and the location where the CSST is not really well bonded to your 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 to the building’s electrical ground system: the level of the electrical charge from an indirect lightning strike was reduced (with their study) from 97% of the charge as a result of 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 as being a proposal on the National Fuel Gas Code. In 2009 the same authors reported that CSST could perform acceptably but made important and detailed recommendations for the soil bonding of CSST gas piping systems.
Goodson inside a patent application (2009) also reported on the potency of direct bonding of both yellow and black CSST gas piping to reduce the danger of damage from indirect lightning flashing. Goodson explained that CSST was generally not really a good electrical ground, thus lending importance towards the “direct bonding” discussion with this gas piping system. Stringfellow (2013) continued to report on electrically-induced gas distribution piping.
Currently (2015) the manufacturers have virtually switched to a improved, more durable CSST gas piping whose design incorporates a protective outer jacket and also for which extra manufacturer-specified ground bonding is not required. I think that only Ward consistently make the yellow CSST accessible in the Usa
As outlined by Jim Narva, executive director from the National Association of State Fire Marshals, that association is working on informing homeowners of the requirement for retrofit ground bonding of older CSST installations.
OPINION: I agree that CSST needs to be shielded from damage, including or perhaps in particular after it is run through building cavities where, hidden from view, it’s otherwise too simple for a future building occupant or worker to shoot a nail or screw throughout the material. One could think that excluding concerns for corrosion, similar worries relate to (and usually prohibit the usage of) flexible copper tubing when utilized for gas piping: it is not necessarily routed within building cavities. Instead in those situations it’s present with use steel piping for such gas lines.
From the CSST installation example specifications listed here you’ll notice that the makers typically require numerous installation details to ensure safe reliable operation of your gas piping system, including nail plates, flexible corrugated steel armor in some locations, support, as well as other measures. Some local jurisdictions further detail CSST gas piping installation specifications including how and where it may be routed.
Below at left is an illustration of a regular steel gas pipe routed using a wall cavity during building renovations of a New York Home. And at below right you can see the traditional vary from flexible copper tubing to corrugated stainless steel pipe if the gas piping system was required to penetrate the building wall.