Also see our “Pipelines 101” slide deck. Gas extraction glossary below.
- Affected Impact Radius (AIR) – a zone around a natural gas transmission line defined as the radius of a circle where a potential failure (rupture/explosion) could impact people or property to a moderate amount. AIRs are an outer ring to the Potential Impact Radius, within which signiticant to total damage is possible. It is also sometimes considered a minimum range considered for evacuation if a pipeline failure appears to be imminent. Related, also see PIR and HCA.
- City Gate – A pipeline city gate (or citygate) is the critical infrastructure point where high-pressure, long-distance interstate natural gas transmission pipelines transfer custody of gas to local distribution companies (LDCs) for residential and commercial delivery. It acts as the gateway to a city’s local distribution network, reducing pressure and odorizing the gas.
- Compressor Station -A pipeline compressor station is an above-ground facility that uses compressors (driven by turbines, motors, or engines) to pressurize natural gas. These stations maintain gas flow efficiency, compensating for friction and elevation changes that reduce pressure over long distances. The are located every 40 to 100 miles along a natural gas pipeline.
- High Consequence Area (HCA) – HCAs are zones within 220 yards of a pipeline with high occupancy dwellings or identified sites where people congregate or are confined, such as a hospital, daycare facility, prison facility, or a retirement or assisted-living facility that a potential pipeline failure could affect. Related, also see PIR and AIR.
- Interstate vs. Intrastate – Pipelines that cross state boundaries are Interstate. Pipelines contained entirely within one state are Intrastate. Interstate pipelines need to be approved by the Federal Energy Regulatory Commission (FERC) as well as various other state and federal permits. Intrastate pipelines only need to meet state permit requirements.
- LDCs (Local Distribution Companies) – Local gas distribution companies that purchase gas off the gas transmission pipeline system.
- “Lift & Lay” – projects where an existing pipeline segment is removed and a new, usually larger segment is installed. Also see “T&R”.
- Loop or Looping – A pipeline loop is an additional length of pipeline laid parallel to an existing pipeline and connected at both ends. “Looping” is used to create more storage capacity on a pipeline system.
- MAOP (Maximum Allowable Operating Pressure) – the highest pressure a pipeline system is allowed to operate within. The intended MAOP of a pipeline determines the strength and thickness of the pipeline walls, and placement of inline valves. This pressure rating is also combined with the diameter of a pipeline to determine its Potential Impact Radius (PIR).
- M&R (Metering and Regulation Station) – A metering and regulation station is a critical pipeline facility that measures the volume of gas (metering) and reduces its pressure (regulating) for safe, accurate transfer to customers or lower-pressure distribution networks.
- “Natural” Gas (aka Methane Gas or Fracked Gas) – Gaseous byproduct of oil drilling made of approximately 90% methane. Not to be confused with LNG (natural gas cryogenically liquified at -260°F for transport or storage), or NGLs (Natural Gas Liquids – liquid byproducts brought up from gas drilling. Butane, Ethane, Propane.) The term “natural” gas was coined by the oil & gas drilling industry.
- PIG and Pigging Facilities (Pipeline Inspection Gauge) – PIGS are devices that are inserted and run through pipelines to push out fluids and other build-up. Smart PIGS have sensors that report back the condition of the pipeline segments they’re run through. PIG Launcher / Receiver facilities are pipeline segments that rise above ground where the PIGS are inserted and removed from the pipeline. PIG Launcher / Receiver facilities include “blow-down” valves that vent gas to relieve pressure.
- POD (Point of Delivery) – Point where gas is delivered off of the gas transmission pipeline. This could be a City Gate for a Local Distribution Company (LDC),
- Potential Impact Radius (PIR) – a zone around a natural gas transmission line defined as the radius of a circle where a potential failure (rupture/explosion) could significantly impact people or property. The pipeline industry will sometimes also use the term “incineration zone” because of the high level of damage with in a PIR. Related, also see AIR and HCA.
- T&R (Take-Up & Re-Lay) – projects where an existing pipeline segment is removed and a new, usually larger segment is installed. Also see “Lift & Lay”.