Natural gas meters and their associated supply lines are critical pieces of hardware that distribute an abundant energy source. The problem is this essential hardware is susceptible to damage, the results of which can be minor to severe.
While this is true for all gas meters and supply lines used across the world, it is especially true in natural gas hubs that provide the energy source to multiple users. These hubs, known as farm taps, link natural gas piping to interstate or intrastate transmission and supply pipelines.
In recent years, farm taps have come under increased scrutiny in the United States. Originally, these high-pressure connection points were found in rural areas, but they’ve become increasingly common in more heavily populated regions. Because of this trend, farm taps are more susceptible to damage from external forces, such as vehicle impacts or acts of nature.
Farm tap regulation falls under the purview of the Gas Distribution Integrity Management Program (DIMP), which the U.S. Department of Transportation’s Pipeline and Hazardous Materials Administration (PHMSA) oversees. The specific DIMP regulations that apply to farm taps can be found in 49 CFR Part 192, Subpart P and § 192.740.
In summary, the DIMP regulations mandate that farm taps must meet four requirements:
Farm taps have this type of regulation because of their importance to the natural gas supply chain. Unlike residential or commercial gas meters and supply lines, which only supply and monitor gas for a specific location, farm taps connect multiple users to natural gas. Should an accident occur to the farm tap, not only could the damage result in a fire or explosion, but it also disrupts natural gas service to several people.
Fortunately, potential disruptions may be mitigated with the patented HaloValve, a natural gas safety breakaway valve that runs in the riser pipe between grade and the gas meter. HaloValve serves as an intentional weak point in the piping assembly whenever a high-lateral impact occurs. When that happens, the valve disconnects, forcing the gas to stop flowing.
When the valve disconnects, a force-loaded spring pushes a ball inside the fitting into the area where the valve has separated from the meter. The ball acts as a plug that instantly stops gas from leaving the supply line. By stopping the gas, the risk of fire, explosion, property damage and serious personal injury may be mitigated, as well as the loss of saleable gas to the atmosphere.
All HaloValve models are constructed of corrosion-resistant 316 stainless steel with nitrile seals. A general-purpose HaloValve has a pressure rating of 300 psi (21 bar) and is rated for use in temperatures ranging from -40ºF to 212ºF (-40ºC to 100ºC). For farm taps, HaloValve offers a high-pressure version rated for pressures up to 1,000 psi (69 bar).
HaloValve is available in four-and six-foot lengths, and both FNPT and MNPT connections. The HaloValve is currently compatible with 3/4-inch line sizes, though a 1-inch model is currently under development.