Does anyone know anything about corrugated stainless steel tubing (CSST)?

----- Original Message -----
To: nick gromicko
Sent: Tuesday, September 25, 2007 12:16 PM
Subject: Re: CSST

CSST is corrugated stainless steel tubing. Do you know anything about it?

Thank you for your assistance.

Kind of an open ended question but yes. BK posted some good sites to start in.

Brian has led to the right track of things of this subject.


Let us not forget the safety behind a new product use and installation hazards it may indirectly provide.

Corrugated stainless steel tubing (CSST) that has been used in residential, commercial and industrial buildings after Sept. 5, 2006. The tubing is used to transmit gas throughout the structure in lieu of hard pipe gas lines.

According to the plaintiffs in the case, tubing manufactured by Titeflex, Ward, OmegaFlex or Parker Hannifin poses an unreasonable risk of fire from lightning strikes. The tubing in question is stamped with one of the manufacturers’ marks.
CSST is a continuous, flexible, stainless steel pipe that typically is covered with a yellow plastic coating. It is usually installed along floor joists, above basements, in attic spaces or connected to exposed appliances such as water heaters.
The suit alleges that the tubing is not thick enough to prevent damage in the event of a lightning strike and that the manufacturers have failed to warn consumers about this alleged danger.
Under the proposed settlement, those who qualify, which includes home owners will receive payment vouchers of between $200 and $2,000 to defray the cost of buying and installing a lightning protection system, or between $75 and $160 to install a bonding and grounding system.
Participants who plan to make a claim must submit a claim form to the CSST Settlement Administrator by Sept. 5, 2007.
A hearing to determine whether the proposed settlement is fair, reasonable and adequate will be held in the Circuit Court of Clark County, Ark. on Feb. 1.
For more information, visit, call the CSST Settlement Administrator at 800-420-2916, or write the administrator at P.O. Box 4349; Portland, Ore. 97208-4349.

Since 1989 over 150 million feet has been installed in residential, commercial, and industrial structures. During 2002, approximately 45 million feet of CSST was sold and installed in the U. S. - an indication of the rapid increase in use of CSST in recent years.

Corrugated stainless steel gas tubing (CSST) consists of a continuous, flexible, stainless steel pipe with an exterior PVC covering. The piping is produced in coils that are air-tested for leaks. It is most often installed in a central manifold configuration (also called parallel configuration) with “home run” lines that extend to gas appliances. Flexible gas piping is lightweight and requires fewer connections than traditional gas piping because it can be bent easily and routed around obstacles.

Broken gas lines can occur during extreme conditions, like earthquakes and floods, or when appliances are improperly moved while being serviced or cleaned. Excess Flow Valves (EFVs) can be installed both at meters and at individual appliances to restrict the flow of gas when an excessive flow (due to a line rupture, or disconnected fitting) is detected.
Excess flow valves have been used for a significant period of time in commercial and industrial applications as a safety and hazard reduction measure. They have come to be used for low-pressure, above-ground applications only since the early 1990’s. There are two principal types of these valves.

  • Non-Bypass Valves (EFVNB) are designed to trip and close, forming a seal that is essentially gas tight. These valves generally must be reset manually after the leak or rupture has been repaired.
  • Bypass Valves (EFVB) allow a small amount of gas to pass through (bypass) after it has tripped, which allows the valve to be automatically reset once the flow has been reduced below the threshold level.
    At the present, only bypass valves are used for low pressure applications (after the meter and regulator) within homes. These valves are known as low pressure excess flow valves (EFVs), and close by way of a calibrated float ,spring, or magnet when gas flow that is higher than the rated design is detected. When closed, the bypass valves greatly restrict the flow of gas, allowing only a small quantity of gas to escape. This reduces or eliminates the risk of fire or explosion if properly sized and installed. Since they are bypass valves, they automatically reset after the flow has been reduced below the trip point.
    Because excess flow valves rely on gas line pressure variance to sense ruptures, they are sized for each appliance that is serviced by a gas line (or the maximum flow rate of the line) and can be located downstream of the meter or manifold or between the gas service line and the appliance’s connection line. These locations are required by building codes to be accessible, so installing EFVs in existing homes should not be a complex undertaking.
    Excess flow valves are available for either natural gas or propane gas and can be used with black iron pipe and CSST. Some EFVs are built into the appliance gas connection line. Because gas shut off devices vary depending on the type and magnitude of event that would trigger a valve to close and where and how the valves are installed, only licensed plumbers experienced with gas line sizing should specify and install the devices.

These are only a few things to look for in using a new product.
As always, the product should be installed per Manufacturers Instructions and as HI’s we should be able to recognize any indication of improper installations and flag it when unsure or recommend further evaluation by the proper professionals of the trade.

Hope this helps.

Marcel :slight_smile: :slight_smile:

As usual, you are a font of information. Thanks