Preface
This sixth edition of CSA Standard Z184 (now CAN/CSA-Z184), Gas Pipeline Systems, supersedes previous editions published in 1968, 1973 (entitled Gas Transportation and Distribution Piping Systems) and 1975, 1979, 1983 (entitled Gas Pipeline Systems).
This Standard is part of the Pipeline Systems and Materials segment of CSA's Transportation program.
This edition differs from the fifth edition mainly as follows:
(a) A general renumbering of clauses throughout the text and appendices to achieve consistency with other CSA pipeline standards.
(b) The elimination of offshore pipeline requirements in recognition of the CSA Preliminary Standard 2187- M1984, Offshore Pipeline Systems.
(c) Clause 3, Definitions, has been revised with a number of additions and deletions.
(d) Clause 4, Materials, has been revised in regard to notch toughness requirements and acceptable alternative materials.
(e) Clause 5, Design, has been revised to include requirements for mechanical interference fit joints.
(f) Clause 6, Joining, has been revised to include optional fabrication shop standards of acceptance, optional maintenance welding, and a new carbon equivalent formula.
(g) Clause 10, Operating, Maintenance, and Upgrading, has been revised to include a change of class location engineering assessment, requirements for evaluating and treating localized external corrosion, and requirements for maintenance welding.
(h) Appendix K has been added to outline standards of acceptability for circumferential pipe butt welds based on fracture mechanics principles.
This Standard contains basic reference data and formulae related to design, supplemented by specific requirements where necessary, to obtain a uniform interpretation of the design requirements. It refers to unsafe practices, which are prohibited, and sets out warnings where caution must be exercised. In addition, this Standard contains a list (Appendix A) of applicable reference standards organizations, which may be of interest to users of this Standard.
The intent of this Standard is to establish essential requirements and minimum standards for the design, installation, and operation of gas pipeline systems. It is not a design handbook and the need for exercising competent engineering judgement is a necessary requirement to be employed concurrently with its use.
The requirements of this Standard are adequate under conditions normally encountered in the gas industry. Requirements for abnormal or unusual conditions are not specifically provided for, nor are all details of engineering and construction prescribed. It is intended that all work performed within the scope of this Standard shall meet or exceed the safety standards expressed or implied herein.
As with all new editions, it is to be expected that changes may have to be made from time to time based on new experience or technology, or both. When necessary, amendments will be made by the Committees and published in accordance with CSA practices. This Standard was prepared by the Technical Committee on Gas Pipeline Code under the jurisdiction of the Standards Steering Committee on Pipeline Systems and Materials and was formally approved by these Committees. It has been approved as a National Standard of Canada by the Standards Council of Canada.
Scope
1.1
This Standard covers the design, fabrication, installation, inspection, testing, and safety aspects of the operation and maintenance of gas pipeline systems including gathering lines, transmission lines, compressor stations, metering and regulating stations, distribution lines, and service lines.
1.2
The Scope of this Standard, which includes the following, shall be as shown in Figure 1.1:
(a) gas storage vessels of the bottle-type or closed pipe-type fabricated or forged from pipe or fabricated from pipe and fittings, and gas storage lines; and
(b) the conditions of use of the elements of the pipeline systems described in Clause 1.1.1, including, but not limited to, pipe, valves, fittings, flanges, bolting, gaskets, regulators, pressure vessels, pulsation dampeners, and relief valves.
Note: Designers are cautioned that, while some sections apply to other gases, this Standard was prepared as a minimum standard for the design, construction, and operation of gas distribution and transmission systems as portrayed in Figure 1.1.
1.3
This Standard does not apply to
(a) design and fabrication of pressure vessels that are covered by appropriate pressure vessel codes;
(b) piping with metal temperatures above 230° C or below -70° C;
(c) piping beyond the termination of the utility installation*;
*For such piping, see CGA Standard CAN1-8 149. 1-M86, Natural Gas Installation Code.
(d) piping in oil refineries, natural gasoline extraction plants, gas treatment plants (except main gas stream piping in dehydration and all other processing plants installed as parts of gas pipeline systems), gas manufacturing plants, industrial plants, or mines;
(e) vent piping for waste gases of any kind operating at or near atmospheric pressure;
(f) wellhead assemblies, including control valves and casing and tubing in gas or oil wells;
(g) proprietary items of equipment, apparatus, and instruments;
(h) heat exchangers;
(i) oil and liquid products pipeline systems;
(j) prefabricated units that employ plate and longitudinal welds rather than pipe;
(k) liquefied natural gas pipeline systems; and
(I) offshore pipeline systems.
1.4
This Standard is intended to establish essential requirements and minimum standards for the design, installation, and operation of gas pipeline systems. It is not a design handbook and the need for exercising competent engineering judgement is a necessary requirement to be employed concurrently with its use.
1.5
The requirements of this Standard shall be applicable to the operation, maintenance, and upgrading of existing installations; however, it is not intended that such requirements be applied retroactively to existing installations insofar as design, construction, and established operating pressures are concerned.
1.6
Where any requirements of this Standard are at variance with the requirements of other standards or codes incorporated by reference into this Standard, the requirements of this Standard shall govern.
1.7
It is not the intent of this Standard to prevent the development of new equipment or practices, or to prescribe how such innovations should be handled.