| The natural gas delivery system |
Natural gas travels through a complex network of pipelines, compressor stations and metering systems to reach homes and businesses. Compressor stations keep gas pressurized for long-distance transport, while local metering and regulating stations reduce pressure to safe levels for residential and commercial use. Understanding this system is essential for identifying which valves are safe to operate during emergencies. |
| Never operate underground pipeline valves |
| Valves that control underground pipelines are critical components of compressor and regulating stations and are strategically placed along transmission pipelines and distribution mains. First responders must NEVER attempt to open or close valves on underground gas pipelines. Doing so could result in sudden over-pressurization elsewhere in the system, causing explosions or widespread outages. Only trained utility personnel should operate these valves. |
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| Never operate relief valves |
Relief valves are engineered safety devices that prevent dangerous over-pressurization in the natural gas pipeline system. Typically found in high-pressure distribution stations and pressurized storage locations, these valves automatically open to vent excess gas and close once pressure returns to normal levels. First responders must NEVER attempt to operate relief valves or restrict their vents. Improper operation could result in pressure buildup, system failures or catastrophic explosions. Only trained utility personnel should manage relief valve systems. |
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| Safe valve operation guidelines |
In gas emergencies, first responders who have received proper training may safely close two types of valves: |
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The aboveground shutoff valve at a service meter. |
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Individual natural gas appliance shutoff valves, typically located within 6 feet of the appliance. |
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| Follow these important safety precautions when closing any valves: |
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Only close a valve if you have been properly trained and it is safe to do so. |
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Turn the valve a quarter‑turn so that the indicator is perpendicular to the piping. |
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Immediately notify the utility of any valve you have closed. |
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Never attempt to reopen a closed valve. Only utility personnel may restore service. |
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| Special circumstances |
| Gas regulator malfunction. Regulators are present on high‑pressure service laterals to reduce gas pressure to levels that residential appliances can safely use. Regulators may be located either inside or outside a building. If a regulator malfunctions, it can leak high‑pressure gas, creating a serious ignition hazard. If properly trained, you may control a gas leak from a malfunctioning regulator by closing the shutoff valve on the high‑pressure piping before the meter. |
| Curb valve operation. Curb valves, located at or near property lines on service lateral gas lines, provide emergency shutoff capability. In some parts of National Grid’s service area, first responders have received specific tools and training for operating these valves. Do NOT operate curb valves unless you have been trained and equipped to do so. |
| Minimize ignition risks |
| In any incident where natural gas is leaking, notify National Grid through your dispatcher as soon as practicable and take these precautions to prevent a spark from igniting the gas: |
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Eliminate open flames and cigarettes (including e‑cigarettes and vape pens). |
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Do not turn on or off any lights or electrical appliances/devices. Use only intrinsically safe radios and flashlights. |
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Do not use TV remotes or garage door openers. |
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Do not ring doorbells or use garage door openers. Knock instead. |
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Do not step on doormats or shuffle across carpet. Friction from boots could create a spark of static electricity. |
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