Corrugated stainless-steel tubing is now approved for nationwide use.

For proponents of corrugated stainless-steel tubing, 2002 was a banner year. After years of fighting for inclusion in building codes across the nation, most notably the battle in California, nationwide approval for CSST has been won.

The International Association of Plumbing and Mechanical Officials has long been an opponent of CSST as an alternate material for gas piping. However, it recently reversed its position and approved CSST for inclusion in its 2003 Uniform Plumbing Code.

"This approval pretty much opens the door (for CSST) in all 50 states," says Jeff Soechting, Ward Manufacturing's product manager for gas products. There are still some jurisdictional problems with some cities or counties that are resisting CSST, but he says they are more isolated now than in the past.

California was the last state that had restrictions, says Bob Torbin, manager of business development at Foster-Miller Inc., an engineering consulting company. The reversal of the state's Department of Housing and Community Development's viewpoint and subsequent inclusion in the California Plumbing Code was a major breakthrough, but a moot point after IAPMO's decision.

"All the major plumbing and gas codes will now include CSST as an acceptable alternative material," he says. That includes the Uniform Plumbing Code, the International Fuel Gas Code and the National Fuel Gas Code.

IAPMO's reversal is most likely the result of its partnership with the National Fire Protection Association, says Dan Roberts, manager of application engineering at Gastite. The NFPA was one of the first code bodies to recognize CSST. In order to compete with the international code series, IAPMO had to make some concessions on its CSST stance.

Pros & Cons

Why did it take so long for CSST to gain approval in the United States? The product has been used in Japan and Europe since 1980, and was introduced in this country in 1989. Since then it has been a reliable and safe product.

Most of the objections have come from the unionized trade, explains Ed Moran, national sales manager at Omegaflex. Many claim the product is costing them jobs, or they object to the price.

"They see it as threatening labor, but that myth is being overcome," he says. Another objection is a perceived lack of substantiality compared to black steel pipe, says Frank Stanonik, chief technical advisor for the Gas Appliance Manufacturers Association.

"But it is becoming more accepted, especially in retrofit projects, because it can be installed quickly and less expensively than black pipe," he says. "And builders are always looking for better technology."

Moran agrees: "Once the product is in the contractor's hands, he begins to see the value of the installed product -- the labor savings."

The flexibility of CSST is one advantage to the product, Soechting says, "but, more importantly, it provides a higher level of safety because it eliminates all the connections behind the wall you usually have with steel pipe. With steel pipe, every time you change direction you have to have a fitting. With CSST, you simply shape it through the structure and you have one continuous run of piping. The fewer fittings you have, the fewer potential leak problems you have."

Ward Manufacturing has found the response by the trades to be overwhelmingly in favor of the product, he notes. They like the ease of installation the product offers and the ability to complete more jobs than they could using traditional steel pipe. And because CSST installs with simple hand tools (no equipment investment required), corrugated tubing has opened up more work for HVAC and plumbing contractors, even those who were not involved with gas piping before.

Another big plus for corrugated tubing is that it is sold as a system that includes the tubing, the fittings and the mechanical protection devices, rather than as a commodity item like steel pipe, Torbin explains. "Makers of steel pipe make no warranties, express or implied, that steel pipe is suitable for gas service. But CSST is sold as a system designed specifically for LP or natural gas and is certified by a third-party certifier. This makes it unique in the family of acceptable gas-piping materials."

"It is the only gas-piping material that complies with ANSI standards," adds Roberts.

Other ways in which CSST is attractive to the plumbing community is that it's typically installed in half the time used for steel pipe or with half the number of people.

"These are big benefits to a small mechanical contracting company, a Mom and Pop operation, because now they can be competitive with the big boys," Torbin says. CSST levels the playing field for small contractors, yet large contractors are attracted to the product because they can do more work without hiring more people.

He adds that there are indirect savings from using CSST:

  • The job is less likely to be held up because you're not dealing with heavy equipment;
  • Its flexibility allows it to bypass obstacles such as pipes, ductwork and wires that could delay a project; and
  • There is less lost time by employees due to injuries and a reduction in workmen's compensation claims because the product is so lightweight.

Market Growth

Since corrugated stainless-steel tubing was first adopted into the National Fuel Gas Code in 1989, well over 150 million feet has been installed in residential, light commercial and industrial applications, Torbin notes. During 2002, an estimated 40-50 million feet of tubing was sold and installed in the United States alone.

"We've had double-digit growth every year from 1989 through 2002," Soechting says. "Demand for the product is growing and acceptability of it is on the rise."

Roberts and Moran also report double-digit growth of CSST for their companies: Gastite has seen "phenomenal growth" of 20-30 percent, and Omegaflex has a growth level "in excess" of 30 percent.

CSST is becoming more accepted in retrofit work because corrugated tubing makes it easier to install more gas appliances in a home than if you were using steel pipe, Torbin says. In retrofit applications, existing homes have the ability to add a new gas appliance with CSST the same way they might add an electrical appliance. "Homes that have corrugated tubing all of a sudden have fireplace logs and barbecue outlets, spa heaters and gas lights," he says.

But new market growth will come in conversion work, he adds -- electric-to-gas conversions in existing buildings where CSST is more cost-effective than steel pipe. Installing steel pipe involves "collateral damage" to a structure, as sometimes walls have to be taken down or torn into; corrugated tubing can be snaked within the walls without destroying them.

In addition, the market for natural gas is growing, and a large percentage of that market is being installed with CSST.

To increase market exposure for CSST, Roberts and Gastite are working with building officials to get them up to speed on how the product is installed. And the industry is working to qualify the product for larger diameters and higher pressures, says Mark Kendall, director of technical services at GAMA.

"There is no application today that black pipe can do that CSST can't do," says Moran. "In fact, this could be the extinction of black pipe. While it may still be used in a hybrid system, its days are numbered."