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 article describes CSST: corrugated steel pipe tubing employed for gas piping in buildings. Since 1990 CSST has been used within many buildings in both exposed and enclosed areas to set up new gas system piping. The article discusses CSST uses, sources, installation specifications, and safety measures to safeguard the gas piping from damage by abrasion, puncture, lightning strikes or some 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 within a wet area. Yellow “Standard” CSST gas pipin galso requires special electrical ground bonding to lower risk 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 may well 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 is just not the same product as being the flexible gas connector tubing (shown below) utilized to actually connect gas appliances on the gas supply system, and various installation and product protection measures will be required. CSST gas piping is commonly used to route gas or LP gas supply using a building while the flexible gas tubing shown below is specifically designed for the 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 United states 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 may be recognized in (usually) long runs in between the building gas source and its reason for use at gas appliances. The gas appliance connector itself (shown inside the photo just above) might be connected directly involving the end from the CSST and also the appliance, or even the CSST may terminate or perhaps be blended with black iron gas piping from the same building.
CSST gas piping is run in exposed locations and thru building cavities including walls, ceilings or floors.
The number of homes have CSST installed? We had trouble relating industry estimates around Census data and United states Energy Information Agency data, but there is no doubt how the piping has become installed in many homes in Canada, the United States, and Japan.
In line with the CSST Safety Website (below), corrugated stainless steel tubing is placed in about 500,000 new homes every year. Since the Usa Census Bureau and Usa HUD February 2015 New Construction Data news release reports a seasonally adjusted annual rate of brand new construction inside the Usa around one million homes, that shows that 50 % of brand new homes are increasingly being designed with CSST gas piping.
Or if we glance at the February housing start data this means that almost 100% newest homes are utilizing CSST gas piping – which sounds a bit dubious. In 2014 the U.S. EIA reported that 27% of all Usa homes were supplied with natural gas and much less than 1% with some other gases.
I’m a dwelling contractor in Wisconsin, I would like more details on steel oval tube useful for gas piping in buildings. It feels like manufacturers don’t require so that it is secured or strapped significantly in any way. ‘m unsure precisely what the codes say about that. I’ve seen it snaked everywhere without support — and what follows is a story of a single consequence (quoting from a message to a manufacturer):
I wonder if you could supply a perception about support and protection requirements for CSST. I simply came back from helping my Brother-in-Law with some issues within his Condo in Boston — he had a sprinkler pop across the winter, so many of the drywall had to be removed to dry things out. When the restoration contractor removed one section of drywall, the aroma of gas poured out. CSST had been snaked through floor trusses and had looped up in a single location, in which a pneumatic nail in the wood flooring installation had punctured it.
Presumably, it has leaked considering that the building was constructed (a decade ago), and been a hazard the whole time. Any “gas” smell people might have noticed was probably masked from the smell of the garage, as the leak is at the ceiling higher than the garage.
Reading a couple of manufacturers’ installation guides, there doesn’t are most often a requirement to SECURE the gas line in any way — it simply needs to be supported every 8′ or so horizontally, right? Inside my Brother-in-Law’s condo, the gas line was snaked around and not really strapped anywhere, even though it was protected by nail plates at stud and joist penetrations. Is this acceptable, based on your guidelines as well as any applicable codes?
I ask, because checking this out may be covered by 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 how the CSST must 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, it has an “escape” for nail penetrations. This failed to prevent the leak I described, since the dexopky14 looped up and was hit by a pneumatically-driven flooring nail… CSST looks like an incredible thing — very easy to install, etc. I wonder in the event you would do a write-up onto it?
A brief history and field connection with CSST utilization in The United States triggered 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 along with other nearby metal pathways create a potential that could encourage electrical arcing problems for the CSST gas lines. Such lightning-related electrical arcing can weaken as well as perforate the gas piping creating dangerous gas leaks.
The chance of arcing problems for 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 can be reduced by direct-bonding from the gas piping system for the building’s electrical ground system: the level of the electrical charge from an indirect lightning strike was reduced (with their study) from 97% in the charge down to 20% by direct electrical bonding on the building’s electrical ground system. Their 2007 report concluded having 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 tips for the floor bonding of CSST gas piping systems.
Goodson within a patent application (2009) also reported on the potency of direct bonding of both yellow and black CSST gas piping to reduce the potential risk of damage from indirect lightning flashing. Goodson explained that CSST was generally not just a good electrical ground, thus lending importance towards the “direct bonding” discussion for this particular gas piping system. Stringfellow (2013) continued to report on electrically-induced gas distribution piping.
Currently (2015) the makers have virtually switched with an improved, more durable CSST gas piping whose design incorporates a protective outer jacket and for which extra manufacturer-specified ground bonding is not required. I feel that only Ward is constantly produce the yellow CSST for sale in the United states
Based on Jim Narva, executive director of the National Association of State Fire Marshals, that association is focusing on informing homeowners of the necessity for retrofit ground bonding of older CSST installations.
OPINION: I agree that CSST needs to be shielded from damage, including or simply particularly when it is run through building cavities where, hidden from view, it’s otherwise too easy for a potential building occupant or worker to shoot a nail or screw throughout the material. One could feel that excluding concerns for corrosion, similar worries relate to (and customarily prohibit the usage of) flexible copper tubing when utilized 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.
In the CSST installation example specifications listed below you’ll see that the makers typically require several installation details to assure safe reliable operation from the gas piping system, including nail plates, flexible corrugated steel armor in some locations, support, and 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 normal steel gas pipe routed using a wall cavity during building renovations of your New York City Home. As well as at below right you will see the regular differ from flexible copper tubing to corrugated stainless steel pipe when the gas piping system were required to penetrate the property wall.