3.1 General

In addition to the definitions, terms and abbreviations given in the TDG Act and TDG Regulations, the following definitions apply in this standard:

Association of American Railroads.

Alteration (Transformation)
A change in a tank car or service equipment that does not change the specification but that changes the certificate of construction.

Assemble (Assembler)
To produce a tank car without welding on the tank car tank.

Bottom Shell (Coque inférieure)
The portion of a tank car tank surface, excluding the heads, that lies within two feet of the bottom longitudinal centreline of the tank car tank when measured circumferentially.

Canadian Service (Service canadien)
An expression used to designate a container used in the handling, offering for transport or transporting of dangerous goods with an origin and a final destination within Canada.

Certificate of Construction (Certificat de construction)
A certificate, in the form specified by the AAR, from the manufacturer of a tank car or ton container certifying that the tank car or ton container and service equipment conform to the requirements of clause 4.1.

Certificate of Inspector's Report (Certificat d'inspection)
A certificate and report of an independent inspector, in the form specified by the Director, certifying that the ton container and service equipment conform to the requirements of clause 4.1.

Check Valve (Vanne anti-retour)
A device that allows flow in one direction and closes against reverse flow.

Class (Classe)
A general designation usually including several tank car or ton container specifications. The word class is used when the designation embraces several specifications. For example the numerals 111 and 106 are classes.

Closure (Fermeture)
A device that closes an opening into a container, or an auxiliary device that closes an outlet or inlet connection on a valve or fitting, including pipe plugs, quick disconnect caps, blind flanges, manway covers, outlet caps, eduction pipe caps, and fill hole covers.

Committee (Comité)
Association of American Railroads Tank Car Committee.

Container (Contenant)
A large means of containment as defined in the TDG Regulations.

Conversion (Conversion)
A change in a tank car that changes its specification.

Cryogenic Liquid (Liquide cryogène)
A refrigerated liquefied gas that is handled or transported at a temperature equal to or less than -100°C (-148°F).

Dangerous Goods (Marchandises dangereuses)
Dangerous goods as defined in the TDG Act, includes dangerous goods listed in Schedule 2 of Appendix E.

Dangerous Goods Toxic by Inhalation (Marchandises dangereuses toxiques à l'inhalation)
For the purpose of tank car selection, any one of the following: 

  1. A liquid other than a mist meeting the criteria in the TDG Regulations for Division 6.1, Packing Group I, because of its inhalation toxicity, whether having the classification of 6.1 or not and assigned to Hazard Zone A or B in accordance with clause 10.5.2; 
  2. A class 2.3 gas assigned to Hazard Zone A, B, C, or D in accordance with clause 10.5.2;
  3. Any dangerous goods identified as an inhalation hazard by a special provision of Schedule 1 in Appendix E.

Director (Directeur)
The Director, Regulatory Affairs Branch, Transport Dangerous Goods Directorate, Transport Canada.

Elevated Temperature Dangerous Goods (Marchandises dangereuses à température élevée)
Dangerous goods that, when offered for transport or transported: 

  1. are in a liquid phase and at a temperature equal to or greater than 100.0°C (212°F); 
  2. are in a liquid phase with a flash point equal to or greater than 37.8°C (100°F) and that are intentionally heated to a temperature equal to or greater than its flash point; or 
  3. are in a solid phase and at a temperature equal to or greater than 240.0°C (464°F).

Excess-flow Valve (Limiteur de débit)
A device that closes automatically against the outward flow of fluid in the event that the flow rate through the device reaches a set value.

Executive Director (Directeur exécutif)
Executive Director, Tank Car Safety, Association of American Railroads.

Filling Density (Densité de remplissage)
The percent ratio of the mass of the dangerous goods in a tank to the mass of water that the tank will hold at 15.6°C (60°F). For cryogenic liquids, the percent ratio of the mass of the dangerous goods in the tank to the mass of water that the tank will hold at the design service temperature.
For the purpose of determining the water capacity of the tank, the mass of 1 L (0.264 US gallon) of water at 15.6°C (60°F) is 1 kg (2.204 lb.).

Grounding (Mise à la terre)
The process of connecting one or more objects to earth in order to minimize differences of electrical potential between objects and the ground.

Hazard Zone (Zone de risque)
One of four levels of hazard, hazard zones A through D, assigned to gases that are toxic by inhalation, as specified in clause 10.5.2. A hazard zone is based on the LC50 value for acute inhalation toxicity of gases and vapours.

Independent Inspector (Inspecteur indépendant)
A person, class of persons, test facility, or agency, independent of both Transport Canada and the party being inspected, who is registered with the Director.

Interior Heater System (Système de chauffage interne)
A piping system within a tank that uses a fluid medium to heat the dangerous goods.

Liquid Dangerous Goods (Marchandises dangereuses liquides)
Dangerous goods that are in liquid or slurry form, including dangerous goods that are under a liquid blanket, at any time during the handling, offering for transport, or transporting.

Maintenance (Entretien)
Upkeep or preservation of a container or any of its components, including repairs.

Manufacture (Fabrication)
To assemble a tank car capable of rolling on its own wheels, or produce operational service equipment or any finished ton container or other containers.

Marking (Marquage)
The application by stenciling or stamping of symbols or words required by this standard.

Material Compatible with the Dangerous Goods (Matériau compatible)
A material that does not react physically or chemically with the dangerous goods in a way that under normal conditions of handling or transportation would cause a condition or release of dangerous goods that could endanger public safety, including corrosion, environmental stress cracking, solvation, fusion or chemical or physical reaction with the dangerous goods.

Modification (Modification)
Any change to the design of a tank car, including an alteration or a conversion that affects the Certificate of Construction.

National Gas Taper Thread.

Nozzle (Manchon)
A sub-assembly consisting of a pipe or tubular section with or without a welded flange on one end.

A tapered pipe thread that conforms to American National Standard ANSI/ASME B1.20.1-1983 (R2006).

Outage (Creux)
For a tank containing a liquid, the volumetric fraction of the tank in the vapour space, expressed as a percentage.

Padding (Gaz de remplissage)
An inert gas deliberately introduced into the vapour space of a tank in order to make the vapour space gas mixture non-flammable or moisture-free.

ppm (ppm)
Parts per million.

Pressure-relief Device (Dispositif de décharge de pression)
A device that is designed to prevent the rise of internal pressure in excess of a specified value, including a reclosing pressure-relief device, a non-reclosing pressure-relief device, or reclosing and non-reclosing pressure-relief devices in combination.

Pressure Tank Car Tank (Citerne de wagon-citerne sous pression)
A tank car tank conforming to any specification within classes 105, 112, 114 or 120.

psi (lb/po2)
Pounds per square inch.

Qualification (Qualification)
A careful and critical examination of an item, including a container, based on a written program, to verify that the item conforms to a standard, followed by a representation that the item conforms to that standard.

Reinforcing Plate (Plaque de renfort)
A metal plate attached directly to a tank by welding, supporting structural components for the purpose of preventing damage to the tank through fatigue, overstressing, denting, puncturing, or tearing.

Release (Rejet)
Includes discharge, emission, explosion, or other escape of dangerous goods, or any component or compound evolving from dangerous goods.

Reliability (Fiabilité)
The quantified ability of a device or structure to be used in a known environment without failure for a specified period.

Repair (Réparation)
Remanufacture or restoration of a container or any of its components to its original function.

Representation (Attestation)
Certification, in writing or in electronic format, on a document or by marking the container, that the container conforms to the requirements set out in this standard.

Safety System (Système de sécurité)
Devices that equip some tank cars, including a tank-head puncture-resistance system, a coupler vertical restraint system, a system used to protect discontinuities including skid protection and protective housings, a thermal protection system, and an insulation system conforming to clause 8.3.19 or to a special provision of Schedule 1, that is used to control pressure or outage.

Service Equipment (Matériel de service)
Devices attached to and forming part of a container and that are necessary for the purpose of filling, loading, unloading, venting, pressure relief, vacuum relief, heating from within the tank, sampling, and measuring. Such devices include vacuum and pressure-relief devices, valves, pressure-relief valves, excess-flow valves, and closures.

Solid Dangerous Goods (Marchandises dangereuses solides)
Those dangerous goods which are in solid, granular, crystalline, or powder form during handling, offering for transport, or transporting.

Specification (Specification)
A specific designation within a class. For example the designations 111A100W3 and 106A500X are specifications.

Stamping (Estampage)
A marking method that removes or displaces material leaving a permanent imprint on the surface to be marked.

Stencilling (Marquage au pochoir)
A marking method using paint or decal.

Stub Sill (Longrine centrale courte)
A longitudinal structural member at the ends of a tank car designed to accommodate the coupler and draft gear, and to transmit coupler forces to the tank car tank or outer shell on tank cars without continuous centre sills.

Tank (Citerne)
A closed container consisting of service equipment, a shell, heads, reinforcing plates, nozzles, reinforcements, or other components welded directly to the tank.

Tank Car (Wagon-citerne)
A railway vehicle, other than a hopper car, to which a tank, other than a fuel tank that is required for the purpose of supplying fuel for propulsion of the railway vehicle, is permanently attached.

Tank Car Facility (Installation pour wagons-citernes)

  1. An entity that manufactures, repairs, inspects, tests, qualifies, maintains, or modifies a tank car, or service equipment including entities that 
    1. install, qualify, or repair interior linings and coatings in tank cars when such linings and coatings are intended to protect the tank car tank against the corrosive action of the dangerous goods; or 
    2. remove and replace tank car service equipment or change gaskets, including replacing pressure seals/O-rings on vacuum or pressure-relief devices, eduction pipe removal and replacement or eduction pipe gasket removal and replacement; 
  2. An entity that only performs one or more of the following operations is not a tank car facility: 
    1. Replace in-kind: 
      1. Rupture disks in safety vents other than on tank cars used in the handling, offering for transport or transporting of Class 2 gases. 
      2. Bottom outlet valve caps 
      3. Hinged manway cover gaskets and/or fill-hole cover gaskets 
      4. Bottom outlet cap gaskets 
      5. Magnetic gauging device rods 
      6. O-rings in gauging device caps 
      7. O-rings in thermometer well housing tubes 
      8. Secondary plugs, chains and flanges external to valves. 
      9. Defective eyebolts on tank cars with hinged manway covers. 
    2. Remove and replace eduction pipe caps or eduction pipe blind flange gasket as part of loading/unloading operations or limited maintenance; 
    3. Replace breather vent filters on tank cars used in the handling, offering for transport or transporting of hydrogen peroxide; 
    4. Monitors and restores the vacuum in the annular space of tank cars used in the handling, offering for transport or transporting of cryogenic liquids, including Class 113 or specification AAR 204W tank cars.

Tank Car Owner (Propriétaire du wagon-citerne)
The person identified by the Owner's Mark in the Universal Machine Language Equipment Register (UMLER) database of the AAR.

Tank Car Tank (Citerne de wagon-citerne)
A tank that is intended for attachment to a railway vehicle to form a tank car, but does not include the service equipment.

Transport Canada.

Transportation of Dangerous Goods Act, 1992, SC 1992, c. 34 (including amendments).

TDG Regulations (RTMD)
Transportation of Dangerous Goods Regulations, SOR / 2001-286 (including amendments).

Ton Container (Contenant d'une tonne)
A tank that is manufactured to conform to the requirements of 

  1. a Class TC 106A or TC 110A tank set out in this standard; or 
  2. a Class DOT 106A, ICC 106A, ICC 110A, or DOT 110A tank set out in Subpart E of Part 179 of US 49 CFR.

Top Shell (Coque supérieure)
The surface of a tank car tank, excluding the heads and bottom shell.

The WP (Working Pressure) of a tank is the sum of the static head, padding pressure, and the dangerous goods vapour pressure at the following reference temperatures:

  1. 46.1°C (115°F) for a non-insulated tank;
  2. 43.3°C (110°F) for a tank having a thermal protection system incorporating a metal jacket that provides at 15.6°C (60°F) an overall thermal conductance of less than or equal to 10.22 kJ/h·m2·°C (0.5 Btu/h·ft.2·°F); and 
  3. 40.6°C (105°F) for an insulated tank conforming to Class 105, 115, 120 or to specification 111A100W3 or 111A100W4 when the overall thermal conductance is equal to or less than the minimum required of a Class 105 or 120.

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