scope:

This Standard contains requirements for the planning and design of Natural Gas (NG) distribution systems (hereafter referred to as "systems") of MOP not exceeding 16 bar. The Standard does not encompass the availability of gas entering the system. Its purpose is to ensure that there is sufficient transportation capacity.

Note 1: Compliance with this Standard ensures that as far as is reasonably practicable, a system is able to maintain a minimum pressure at the maximum peak demand flow rate and that adequate arrangements are established to minimise the risk of a supply emergency (see Appendix 3).

Note 2: Within the GB, reference to NG is of a quality compliant with GS(M)R.

This Standard references the technical arrangements and agreements required between different GTs and non-GT network owners at system boundaries, to ensure there is sufficient transportation capacity.

This Standard is intended to be used by persons in the planning, modelling and design of systems and for the ongoing monitoring and development of existing systems where appropriate.

This Standard is intended to be used for systems as part of the Network (see IGEM/G/1) for network planning and modelling. Where a system is being designed to contribute diurnal storage provision for the overall Network using "linepack", it may be appropriate to consider applying IGEM/GL/2. This Standard does not embrace the physical design, construction, integrity, operation and maintenance of systems nor does it address environmental issues covered by Legislation other than that mentioned in Section 3. Further information is contained in IGEM/TD/3 and IGEM/TD/4 as appropriate.

This Standard applies to the planning of new and replacement of, or extension to, existing installations. It is not retrospective, but it is recommended that existing installations be modified to meet this Standard when appropriate.

Note: Standards rarely cover the retrospective issue of existing installations. They can however set a basis for consideration of performance upon which a risk assessment can be developed.

All pressures are gauge pressures unless otherwise stated.

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".