Glossary

Anomaly
Imperfection, defect, or critical defect in the wall of the pipe.

Blow Down
Scheduled and unscheduled releases of gas from compressor stations. According to PHSMA protocol (192.605), operators are required to create and maintain a procedural manual for maintenance and to follow protocol for scheduled blow downs. These procedures and protocol vary by company.

Class Location
Criterion for pipeline design set by the Code of Federal Regulations ranging from Class 1, rural to Class 4, heavily populated. Class location is based on the number and type of buildings in an area that extends 220 yards on either side of the centerline of any continuous 1-mile length of a pipeline.

Compression
The process of (1) increasing the pressure of gas to maintain its flow in a pipeline system or (2) reducing the amount of data to be stored in an in-line inspection tool.

Corrosion

  • General External – Metal loss on a pipe caused by electrochemical, galvanic, microbiological, or impacts due to environmental conditions.
  • General Internal – Metal loss on a pipe caused by chemical or other impact on the steel from liquids inside the pipe.
  • Pit - External or internal corrosion on the surfaces that results from the generation of a potential (voltage) difference set up by variations in oxygen concentrations within and outside the pit.
  • Stress Corrosion Cracking - A progressive cracking that results from a combination of tensile stress, cathodic protection currents, and a corrosive environment.

Easement
Is the right to use the real property of another without possessing it. A right-of-way agreement between the pipeline company and the property owner is also called an easement and is usually filed in the public records with property deeds. A pipeline right-of-way is a strip of land over and around pipelines where some of the property owner's legal rights have been granted to a pipeline company. Rights-of-ways and easements provide a permanent, limited interest in the land that enables the pipeline company to operate, test, inspect, repair, maintain, replace, and protect one or more pipelines on property owned by others. The agreement may vary the rights and widths of the right-of-way, but generally, the pipeline company's right-of-ways extend 25 feet from each side of a pipeline unless special conditions exist.

Gas Transmission Pipeline
Includes all parts of the physical facilities through which gas moves in transportation, including pipe, valves, and other appurtenance attached to pipe, compressor units, metering stations, regulator stations, delivery stations, holders, and fabricated assemblies.

High Consequence Areas
High consequence area means an area established by one of the methods described in paragraphs (1) or (2) of § 192.903 as follows:

(1) An area defined as:
(i)   A Class 3 location under §192.5; or
(ii)  A Class 4 location under § 192.5; or
(iii) Any area in a Class 1 or Class 2 location where the potential impact radius is greater than 660 feet (200 meters), and the area within a potential impact circle contains 20 or more buildings intended for human occupancy; or
(iv) Any area in a Class 1 or Class 2 location where the potential impact circle contains an identified site.
(2) The area within a potential impact circle containing—
(i)   20 or more buildings intended for human occupancy, unless the exception in paragraph (4) applies; or
(ii)  an identified site.
(3) Where a potential impact circle is calculated under either method (1) or (2) to establish a high consequence area, the length of the high consequence area extends axially along the length of the pipeline from the outermost edge of the first potential impact circle that contains either an identified site or 20 or more buildings intended for human occupancy to the outermost edge of the last contiguous potential impact circle that contains either an identified site or 20 or more buildings intended for human occupancy. (See figure E.I.A. in appendix E.)

(4) If in identifying a high consequence area under paragraph (1)(iii) of this definition or paragraph (2)(i) of this definition, the radius of the potential impact circle is greater than 660 feet (200 meters), the operator may identify a high consequence area based on a prorated number of buildings intended for human occupancy with a distance of 660 feet (200 meters) from the centerline of the pipeline until December 17, 2006. If an operator chooses this approach, the operator must pro- rate the number of buildings intended for human occupancy based on the ratio of an area with a radius of 660 feet (200 meters) to the area of the potential impact circle (i.e., the prorated number of buildings intended for human occupancy is equal to 20 × (660 feet) [or 200 meters]/potential impact radius in feet [or meters] 2).

Identified site means each of the following areas:
(a)  An outside area or open structure that is occupied by twenty (20) or more persons on at least 50 days in any twelve (12)-month period. (The days need not be consecutive.) Examples include but are not limited to, beaches, playgrounds, recreational facilities, camping grounds, outdoor theaters, stadiums, recreational areas near a body of water, or areas outside a rural building such as a religious facility; or

(b)  A building that is occupied by twenty (20) or more persons on at least five (5) days a week for ten (10) weeks in any twelve (12)-month period. (The days and weeks need not be consecutive.) Examples include, but are not limited to, religious facilities, office buildings, community centers, general stores, 4-H facilities, or roller skating rinks; or

(c)   A facility occupied by persons who are confined, are of impaired mobility, or would be difficult to evacuate. Examples include but are not limited to hospitals, prisons, schools, day-care facilities, retirement facilities or assisted-living facilities.
Hydrostatic Retesting
Testing of sections of a pipeline by filling the line with water and pressurizing it until the nominal hoop stresses in the pipe reach a specified value.

Incident
An event that is reported to U.S. Department of Transportation Office of Pipeline Safety that involves fatalities, injuries, property damage in excess of $50,000, unintentional release of natural gas, customer outages, or other conditions that, in the opinion of the pipeline operator, are significant enough that they should be reported.

In-Line Inspection (ILI)
The inspection of a pipeline from the interior of the pipe using an in-line inspection tool. In-Line Inspection Tool (ILI Tool): Device or vehicle, also known as an intelligent or smart pig, that inspects the wall of a pipe.

Landman
A representative of the gas or pipeline company.

Landman Authority
As a representative of the gas or pipeline company, a landman has limited authority in negotiating a Right of Way on your land.

Maximum Allowable Operating Pressure (MAOP)
The maximum internal pressure permitted to the operation of a pipeline as defined by the Code of Federal Regulations.

Maximum Operating Pressure (MOP)
The maximum internal pressure expected during the operation of a pipeline. MOP normally cannot exceed the maximum allowable operating pressure.

Natural Gas
Natural gas comes from both “conventional” (easier to produce) and “unconventional” (deeper, more difficult to produce) geological formations. The key difference between conventional and unconventional natural gas is the manner, ease and cost associated with extracting the resource. In 2005, unconventional gas represented 44% of U.S. lower-48 onshore production. Transporting Marcellus and Utica shale unconventional gases requires additional and expanded categories of pipelines. (Canadian Association of Petroleum Producers )

Dry vs Wet Gas
Natural gas is considered 'dry' when it is almost pure methane, having had most of the other commonly associated hydrocarbons removed. When other hydrocarbons are present, the natural gas is 'wet'.

Natural Gas Measurements
Natural gas can be measured in a number of different ways. As a gas, it can be measured by the volume it takes up at normal temperatures and pressures, commonly expressed in cubic feet. Production and distribution companies commonly measure natural gas in thousands of cubic feet (Mcf), millions of cubic feet (MMcf), or trillions of cubic feet (Tcf).

While measuring by volume is useful, natural gas can also be measured as a source of energy. Like other forms of energy, natural gas is commonly measured and expressed in British thermal units (Btu). One Btu is the amount of natural gas that will produce enough energy to heat one pound of water by one degree at normal pressure. To give an idea, one cubic foot of natural gas contains about 1,027 Btus. When natural gas is delivered to a residence, it is measured by the gas utility in 'therms' for billing purposes. A therm is equivalent to 100,000 Btu, or just over 97 cubic feet, of natural gas.

Operator
Pipeline company.

Permanent ROW
Permanent right-of-ways remain as long as the pipeline remains active and are maintained as “clear zones” therefore trees, temporary and/or permanent structures are prohibited.

Smart Pig
Device or vehicle that inspects the wall of a pipe also known as an in-line inspection tool.

Pig
Generic term for a tool or vehicle that moves through the interior of the pipeline for purposes of inspecting, dimensioning, or cleaning.

Pipeline
The portion of the pipeline system between the compressor stations including the pipe, protective coatings, cathodic protection system, field connections, valves and other appurtenances attached or connected to the pipe.

Pipeline Infrastructure
Includes all parts of the physical facilities used to transport fluid, gas, hazardous liquid, or carbon dioxide.

Pipeline ROW Easement
Consecutive private property easements acquired by, or granted to, the pipeline company to construct and maintain pipelines on consecutive private property easements to transport hazardous liquid and natural gas from source to consumer.

Pipeline System
All portions of the physical facilities through which gas moves during transportation including pipe, valves, and other appurtenances attached to the pipe, such as compressor units, metering stations, regulator stations, delivery stations, holders and other fabricated assemblies. (See 49 Code of Federal Regulations 192)

Potential Impact Circle
Is a circle of radius equal to the potential impact radius (PIR).

Potential Impact Radius (PIR)
PIR means the radius of a circle within which the potential failure of a pipeline could have significant impact on people or property. PIR is determined by the formula r = 0.69* (square root of (p*d2)), where ‘r’ is the radius of a circular area in feet surrounding the point of failure, ‘p’ is the maximum allowable operating pressure (MAOP) in the pipeline segment in pounds per square inch and ‘d’ is the nominal diameter of the pipe- line in inches.

Specified Minimum Yield Strength or Stress (SMYS)
The required strength level a pipe material must exceed.

Survey
(Verb) The examination, measurement, inspection and recording of the area and features of an area of land intended be used to construct a map, plan, or survey. A survey may be used to investigate the options of a proposed pipeline preferred route.
(Noun) A map, plan, or detailing the results of the conducted survey.

Temporary ROW
The temporary ROW is outside the boundaries of the Permanent ROW. Typically needed for working space during construction, the size and longevity of the temporary easement vary depending on the pipeline system needs. Average Temporary ROW requests are 50 feet wide, may be wider or narrower, and grant removal of trees, earth and all obstructions to pipeline construction.

Transmission Line
As defined in 49 Code of Federal Regulations 192, a pipeline, other than a gathering or distribution line, that transports gas from a gathering or storage facility to a distribution center or storage operates at a hoop stress of 20 percent or more of the specified minimum yield stress of the pipe, or transports gas within a storage field.