Corrugated steel tubing useful 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: corrugated steel pipe tubing utilized for gas piping in buildings. Since 1990 CSST has been used within many buildings within both exposed and enclosed areas to put in new gas system piping. This article discusses CSST uses, sources, installation specifications, and security measures to guard the gas piping from damage by abrasion, puncture, lightning strikes or another hazards. Gas piping codes and industry causes of CSST are included.
Our page top photo, provided thanks to Carson Dunlop Associates, a Toronto home inspection & education firm, illustrates an improper setting up 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 lower likelihood of damage & leaks in regions 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 the following paragraphs.
Watch out: Let’s avoid a point of confusion: CSST used as gas piping runs in buildings will not be the identical product as the flexible gas connector tubing (shown below) employed to actually connect gas appliances to the gas supply system, and other 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 made for your connection of gas appliances on the gas piping system.
Look for corrugated steel tubing (CSST) used as gas piping in buildings constructed within the United states or Canada after 1990 plus seek out it in older buildings where gas piping was newly installed or modified since 1990. CSST is additionally installed 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 in the photo just above) could be connected directly between your end of your CSST along with the appliance, or even the CSST may terminate or be mixed with black iron gas piping from the same building.
CSST gas piping is run in both exposed locations and thru building cavities including walls, ceilings or floors.
Just how many homes have CSST installed? We had trouble relating industry estimates along with us Census data and Usa Energy Information Agency data, but there is no doubt that the piping has been installed in many homes in Canada, the United States, and Japan.
According to the CSST Safety Website (below), corrugated stainless tubing is positioned in about 500,000 new homes each and every year. Because the United states Census Bureau and U.S. HUD February 2015 New Construction Data news release reports a seasonally adjusted annual rate of brand new construction inside the United states of about 1 million homes, that suggests that 1 / 2 of brand new homes are being constructed with CSST gas piping.
Or maybe if we look at the February housing start data that means that almost 100% of brand new homes use CSST gas piping – which sounds somewhat dubious. In 2014 the U.S. EIA reported that 27% of all Usa homes were provided with natural gas and fewer than 1% with many other gases.
I’m a dwelling contractor in Wisconsin, I would personally like more information on elliptical tube utilized for gas piping in buildings. It seems like manufacturers don’t require so that it is secured or strapped quite definitely in any way. ‘m not sure what the codes say about this. I’ve seen it snaked just about everywhere without support — and here is a story of one consequence (quoting from an e-mail to a manufacturer):
I wonder should you could deliver a concept about support and protection requirements for CSST. I simply came back from helping my Brother-in-Law with just a few issues within his Condo in Boston — he possessed a sprinkler pop on the winter, so a lot of the drywall had to be removed to dry things out. If the restoration contractor removed one area of drywall, the aroma of gas poured out. CSST ended up being snaked through floor trusses along with looped up in a single location, where a pneumatic nail in the hardwood flooring installation had punctured it.
Presumably, it offers leaked ever since the building was constructed (a decade ago), and been a hazard the whole time. Any “gas” smell people probably have noticed was probably masked with the smell of the garage, since the leak is in the ceiling over the garage.
Reading a few manufacturers’ installation guides, there doesn’t seem to be a requirement to SECURE the gas line by any means — it really needs to be supported every 8′ approximately horizontally, right? Within my Brother-in-Law’s condo, the gas line was snaked across and not really strapped anywhere, while it was protected by nail plates at stud and joist penetrations. Is this acceptable, according to your guidelines as well as any applicable codes?
I ask, because checking this out may be covered with insurance, if it’s seen as a hazard or perhaps not as much as code or manufacturer’s specifications. Thanks, J.
The manufacturer’s reply was essentially the CSST would have to be kept 3″ away from finished surfaces or protected by nail plates if also within 5″ of some constraint (similar to a penetration using a framing member). Beyond that, they have an “escape” for nail penetrations. This failed to stop the leak I described, since the dexopky14 looped up and was hit by a pneumatically-driven flooring nail… CSST seems like a fantastic thing — simple to install, etc. I wonder in the event you would do a write-up onto it?
The history and field experience of CSST utilization in Canada And America led to concerns about possible pitting, corrosion or perforation of your 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 other nearby metal pathways build a potential which may encourage electrical arcing damage to the CSST gas lines. Such lightning-related electrical arcing can weaken and even perforate the gas piping leading to dangerous gas leaks.
The risk of arcing damage to CSST is increased in locations where lightning activity is greatest and the location where the CSST will not be well bonded to your grounding system.
The authors demonstrated that lightning-related electrical arcing damage risk to CSST could be reduced by direct-bonding of 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% in the charge as a result of 20% by direct electrical bonding towards the building’s electrical ground system. Their 2007 report concluded by using a recommendation for direct ground bonding of CSST as 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 within a patent application (2009) also reported on the effectiveness of direct bonding of both yellow and black CSST gas piping to minimize the risk of damage from indirect lightning flashing. Goodson explained that CSST was generally not really a good electrical ground, thus lending importance for 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 basically switched to an improved, stronger CSST gas piping whose design incorporates a protective outer jacket and also for which extra manufacturer-specified ground bonding is not needed. I feel that only Ward will continue to produce the yellow CSST for sale in the Usa
In accordance with Jim Narva, executive director of your 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 against damage, including or maybe in particular after it is run through building cavities where, hidden from view, it’s otherwise too easier for a future building occupant or worker to shoot a nail or screw with the material. One would feel that excluding concerns for corrosion, similar worries relate to (and usually prohibit the application of) flexible copper tubing when employed for gas piping: it is far from routed within building cavities. Instead in those situations it’s common to use steel piping for such gas lines.
From the CSST installation example specifications listed here you’ll realize that the makers typically require numerous installation details to make sure safe reliable operation in the gas piping system, including nail plates, flexible corrugated steel armor in some locations, support, along with 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 this a conventional steel gas pipe routed using a wall cavity during building renovations of your Ny Home. And also at below right you can see the traditional change from flexible copper tubing to CSST tube once the gas piping system were required to penetrate the property wall.