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 informative article describes CSST: carbon steel oval tube tubing utilized for gas piping in buildings. Since 1990 CSST has been utilized within many buildings in exposed and enclosed areas to setup 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 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 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 lessen 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 may well 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 point of confusion: CSST used as gas piping runs in buildings is just not exactly the same product since the flexible gas connector tubing (shown below) employed 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 commonly used to route gas or LP gas supply through a building even though the flexible gas tubing shown below is specifically designed for the connection of gas appliances towards the gas piping system.
Look for corrugated steel tubing (CSST) used as gas piping in buildings constructed within the U.S. 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 also positioned in other countries.
Collapsing building © Daniel FriedmanStandard “yellow” or newer black CSST can be recognized in (usually) long runs between the building gas source along with its point of use at gas appliances. The gas appliance connector itself (shown inside the photo just above) may be connected directly between the end from the CSST as well as the appliance, or the CSST may terminate or even be together with black iron gas piping inside the same building.
CSST gas piping is run within exposed locations and thru building cavities for example walls, ceilings or floors.
The amount of homes have CSST installed? We had trouble relating industry estimates around Census data and Usa Energy Information Agency data, but it is obvious how the piping has been installed in many homes in Canada, the United States, and Japan.
In line with the CSST Safety Website (below), corrugated stainless tubing is set up in about 500,000 new homes every year. As 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 around one million homes, that demonstrates that 1 / 2 of brand new homes are being created with CSST gas piping.
Or if we look at the February housing start data which means that almost 100% of new homes are using CSST gas piping – which sounds somewhat dubious. In 2014 the United states EIA reported that 27% of most United states homes were supplied with gas and much less than 1% along with other gases.
I’m a dwelling contractor in Wisconsin, I would like more details on oval tube useful for gas piping in buildings. It appears as though manufacturers don’t require so that it is secured or strapped very much in any way. ‘m not sure exactly what the codes say about 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 a manufacturer):
I wonder should you could supply an idea about support and protection requirements for CSST. I recently came back from helping my Brother-in-Law with a few issues in the Condo in Boston — he possessed a sprinkler pop over the winter, so a lot of the drywall must be removed to dry things out. When the restoration contractor removed one part of drywall, the scent of gas poured out. CSST ended up being snaked through floor trusses and had looped up in a single location, where a pneumatic nail through the wood flooring installation had punctured it.
Presumably, it offers leaked considering that the building was constructed (ten years ago), and been a hazard the entire time. Any “gas” smell people probably have noticed was probably masked with the odor of the garage, for the reason that leak is in the ceiling on top of the garage.
Reading a couple of manufacturers’ installation guides, there doesn’t are a requirement to SECURE the gas line whatsoever — it simply should be supported every 8′ approximately horizontally, right? Within my Brother-in-Law’s condo, the gas line was snaked around rather than really strapped anywhere, though it was protected by nail plates at stud and joist penetrations. Could this be acceptable, as outlined by your guidelines as well as applicable codes?
I ask, because checking this out could be covered with insurance, if it’s viewed as a hazard or perhaps not up to code or manufacturer’s specifications. Thanks, J.
The manufacturer’s reply was essentially how the CSST should be kept 3″ far from finished surfaces or protected by nail plates if also within 5″ of some constraint (like a penetration through a framing member). Beyond that, they have an “escape” for nail penetrations. This did not prevent the leak I described, since the dexopky14 looped up and was hit from a pneumatically-driven flooring nail… CSST looks like an excellent thing — very easy to install, etc. I wonder in the event you would do a post on it?
A brief history and field experience with CSST use within North America led to 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 also other nearby metal pathways develop a potential that could encourage electrical arcing injury to the CSST gas lines. Such lightning-related electrical arcing can weaken or perhaps perforate the gas piping leading to dangerous gas leaks.
The potential risk of arcing injury to CSST is increased in locations where lightning activity is greatest and the location where the CSST is not well bonded to a grounding system.
The authors demonstrated that lightning-related electrical arcing damage risk to CSST would be reduced by direct-bonding of your gas piping system for the building’s electrical ground system: the degree of the electrical charge from an indirect lightning strike was reduced (within their study) from 97% from the charge right 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 as being a proposal towards the National Fuel Gas Code. During 2009 the same authors reported that CSST could perform acceptably but made important and detailed ideas for the floor 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 much of a good electrical ground, thus lending importance on the “direct bonding” discussion with this gas piping system. Stringfellow (2013) continued to report on electrically-induced gas distribution piping.
Currently (2015) the makers have basically switched with an improved, more durable CSST gas piping whose design includes a protective outer jacket and then for which extra manufacturer-specified ground bonding is not required. I believe that only Ward consistently produce the yellow CSST for sale in the U.S.
In accordance with Jim Narva, executive director of your National Association of State Fire Marshals, that association is centering on informing homeowners of the demand for retrofit ground bonding of older CSST installations.
OPINION: I agree that CSST should be protected against damage, including or maybe in particular when 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 from the material. One could think that excluding concerns for corrosion, similar worries relate to (and customarily prohibit the application of) flexible copper tubing when useful for gas piping: it is really not routed within building cavities. Instead in those situations it’s present with use steel piping for such gas lines.
Within the CSST installation example specifications further down you’ll observe that the manufacturers 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, and also other measures. Some local jurisdictions further detail CSST gas piping installation specifications such as where and how it may be routed.
Below at left is an illustration of a normal steel gas pipe routed by way of a wall cavity during building renovations of any New York City Home. As well as at below right you can observe the conventional vary from flexible copper tubing to CSST tube as soon as the gas piping system needed to penetrate the property wall.