EN 1993-4-3 gives design rules for the structural design of buried pipelines, in particular for the evaluation of the strength, stiffness and deformation capacity.
The rules for local buckling in this part EN 1993-4-3 are in line with those in other pipeline standards.
The design critical curvatures according to EN 1993-4-3 are larger than those that could be deduced from EN 1993-1-6. The main reasons are that the loading in buried pipelines is mainly deformation controlled and the consequences of local buckling are less severe than in structures where the loading is mainly load controlled.
It is recognized that many standards exist for the design of pipelines covering many different aspects.
Examples are routing, pressure safety systems, corrosion protection, construction and welding, operation and maintenance. For aspects other than the structural design of the pipeline itself, reference is made to the relevant European standards listed in 1.3. This is also the case for elements like valves, fittings, insulating couplings, tees and caps.
Because up till now in EN 1991, no rules exist for actions (loads) on pipelines, reference is made to relevant EN standards on pipelines e.g. EN 1594 on gas transmission pipelines and EN 14161 on pipeline transportation systems for the petroleum and natural gas industries.
(1) This Part 4-3 of EN 1993 provides principles and application rules for the structural design of cylindrical steel pipelines for the transport of liquids or gases or mixtures of liquids and gases at ambient temperatures, which are not treated by other European standards covering particular applications.
(2) Standards dealing with specific pipeline applications should be used for these purposes, notably
- EN 805 : 2000 for water supply systems (drinking water);
- EN 1295: 1997 for buried pipelines under various conditions of loading (waste water);
- EN 1594: 2000 for gas supply systems for operating pressures over 16 bar;
- EN 12007: 2000 for gas supply systems up to and including 16 bar;
- EN 12732: 2000 for welding;
- EN 13941: 2003 for pre-insulated bonded pipe systems for district heating;
- EN 13480: 2002 for industrial pipelines;
- EN 14161: 2004 for pipeline transportation systems for the petroleum and natural gas industries.
(3) Rules related to special requirements of seismic design are provided in EN 1998-4 (Eurocode 8:
Part 4 "Design of structures for earthquake resistance: Silos, tanks and pipelines"), which complements the rules of Eurocode 3 specifically for this purpose.
(4) This Standard is restricted to buried pipelines, corresponding to the scope of Eurocode 8 Part 4 for pipelines. It is specifically intended for use on:
- Buried pipelines in settlement areas and in non-settlement areas;
- Buried pipelines crossing dykes, traffic roads and railways and canals.
(5) The design of pipelines involves many different aspects. Examples are routing, pressure safety systems, corrosion protection, construction and welding, operation and maintenance. For aspects other than the structural design of the pipeline itself, reference is made to the relevant European standards listed in 1.2. This is also the case for elements like valves, fittings, insulating couplings, tees and caps.
(6) Pipelines usually comprise several associated facilities such as pumping stations, operation
centres, maintenance stations, etc., each of them housing different sorts of mechanical and electrical equipment. Since these facilities have a considerable influence on the continued operation of the system, it is necessary to give them adequate consideration in the design process aimed at satisfying the overall reliability requirements. However, explicit treatment of these facilities, is not included within the scope of this Standard.
(7) Although large diameter pipelines are within the scope of this Standard, the corresponding design criteria should not be used for apparently similar facilities like railway tunnels and large underground gas reservoirs.
(8) The provisions in this Standard are not necessarily complete for particular applications. Where this is the case, additional provisions specific to those applications should be adopted.
(9) This Standard specifies the requirements regarding material properties of plates and welds in terms of strength and ductility. For detailed guidelines and requirements about materials and welding, reference should be made to the relevant standards listed in 1.2.
(10) The scope of this Standard is limited to steel grades with a specified minimum yield strength not exceeding 700 N/mm2.
