scope:

This Standard covers the design, construction, inspection, testing, operation and maintenance of steel pipelines and certain associated installations (see Figure 1), for the transmission of dry Natural Gas (predominantly methane), with or without odorisation, at MOP exceeding 7 bar and not exceeding 100 bar. The scope may be extended beyond MOP of 100 bar but specific areas will require further justification and documentation which embraces a safety evaluation.

While the Standard may be appropriate for use with other gases, the characteristics of the gas and the consequential effect upon design, material, operations and maintenance of the pipeline have to be taken into account. In this context, other gases are those described by 1^st family, other 2^nd family and 3^rd family gases as defined in BS EN 437.

Note 1: Requirements for steel pipelines of MOP not exceeding 7 bar are contained in IGEM/TD/3, and on steel services in IGE/TD/4.

Note 2: A safety evaluation involves a systematic study of the major hazard potential of a pipeline and its associated installations (see Sub-Section 6.8).

This Standard covers operating temperatures between - 25 °C and + 120 °C inclusive.

This Standard applies to pipelines laid between points on land, including water crossings. For pipelines of which any part is offshore, additional or alternative guidance may be required for the offshore section. However, many of these requirements will remain valid.

Note: Offshore pipelines are those that are on the seaward side of the low water mark or special boundaries drawn at bays and estuaries.

This Standard equally applies to pipework design for certain associated installations, including buried block valves and pig trap installations. IGEM/TD/13 applies to PRIs, manifolds, multi-junction stations, the main pipework at compressor stations, metering installations, connections and other off takes.

Pressures quoted are gauge pressure, unless otherwise stated.

Appendix 2 lists Legislation, Guidance Notes, Standards etc., which are identified within this Standard, as well as further items of Legislation that may be applicable. Where Standards are quoted, equivalent national and international Standards, etc. equally may be appropriate. Unless otherwise stated the latest version of the referenced document is to be used.

Italicised text is informative and does not represent formal requirements.

Appendices are informative and do not represent formal requirements unless specifically referenced in the main sections via the prescriptive terms "must", "shall" or "should".