Fire-Exposure Tests Spur Call for Federal Standards and Thermal Activated Shutoff Valves in Natural Gas Networks

In 2019, the Gas Technology Institute (GTI), through its Operations Technology Deployment (OTD) Group, carried out comprehensive testing of several commercially available Thermally Activated Shutoff (TAS) devices. Sponsored by major North American natural gas utilities, this study had several essential objectives:

• Identifying commercially available TAS devices suitable for the natural gas industry.
• Evaluating specific installation requirements of individual units.
• Conducting rigorous performance testing aligned with manufacturers’ designs and specifications.

Through their evaluation, GTI confirmed that thermally activated shut off technology contributes to preventing fire propagation at customer premises. Consequently, adopting TAS devices offers critical advantages in safeguarding lives, protecting property, and ensuring the safety of first responders during fire incidents.

These findings underscore the urgent need for establishing federal standards and promoting widespread deployment of Thermal Activated Shutoff technology within the natural gas industry.

Three leading manufacturers of thermally activated shutoffs participated in the program:

• TECO® SRL, manufacturer of the FireBag®.
• A prominent manufacturer of natural gas regulators that integrates thermal shutoffs into its products.
• A well-known manufacturer of flexible hoses that incorporates thermal shut-off functionality into their appliance connectors.

Notably, an incumbent manufacturer of thermal shutoffs equipped meter swivel connectors chose not to participate in this program.

After extensive testing and evaluation, it was determined that the TECO® FireBag® outperformed other technologies for the following key reasons:

• TECO FireBag offers the widest range of sizes and fitting configurations suitable for natural gas piping systems.
• Versatility to be installed on both high-pressure (MAOP 150 PSIG) service lines and low-pressure (inches water column) lines.
• Lowest shut-off activation temperature, complying with MA DUP Ruling #14899.
• High performance under prolonged high-temperature exposure, maintaining functionality even after fires have been extinguished and cooling has occurred.

In conclusion, the GTI Thermally Activated Gas Shut-Off testing program highlighted the absence of language in federal standard 49 CFR Part 192, for thermally activated shut-off devices. Establishing such a standard would significantly benefit natural gas distribution companies and their stakeholders. GTI recommends advancing efforts toward developing unified U.S. and Canadian standards to regulate the installation and operation of TAS devices. Furthermore, the program identified the need for expanded exploration of high-pressure (>150 PSIG) rated thermal activated devices.

How the TECO FireBag Works

The TECO FireBag Thermally Activated Shutoff (TAS) consists of a zinc-plated steel fitting containing a fusible metal alloy and spring, which when exposed to 203˚- 212˚F temperatures releases a plug producing a metal-to-metal seat, creating a gas-tight seal. Fusible alloys are a reliable technology also commonly used in emergency fire sprinkler systems. Manufactured to German DIN 3586 Standards which specifies the Thermal Activated Shutoff trigger within 60 seconds of the set-off temperature and can withstand a minimum of 1,697˚F, and for a minimum of 60 minutes, allowing time for first responders to reach the dwelling and turn off the gas supply. Since the TECO FireBag is a passive device and only triggers in a fire situation, it is maintenance free, and requires no regular inspections. No fire or heat detectors are required to automatically intercept the gas flow.

Where the TECO FireBag is Used

It is recommended the TECO FireBag should be installed upstream of the gas regulator to ensure the high-pressure gas is turned off in fire situations. When used in low-pressure systems the Teco FireBag should be installed before the meter. It is designed for use on indoor or outdoor installations, with pressure ratings ranging from inches water column to 150 psig MAOP.