BS 1708-1:2010 pdf download – Welding — Basic welded joint details in steel Part 1: Pressurized components
The purpose of this European Standard is to exemplify commonly accepted welded connections in pressuresystems. lt does not promote the standardization of connections that may be regarded as mandatory orrestrict development in any way. Stress analysis rules should be considered if necessary.
This standard contains examples of connections welded by:
Manual metal-arc welding with covered electrode (111);Submerged arc welding (12);
Gas shielded metal arc welding (13);
Tungsten inert gas arc welding;TIG-welding (14);
Plasma arc welding (15)
processes (process numbers according to EN ISO 4063) in steel pressure systems.
Other processes byagreement.
This standard covers welded joint details in steel, but can be applied to other metallic materials. In such casesthe shape and dimensions of the weld should be checked.
The estimation of the suitability of welded connections for special service conditions, for example corrosionand fatigue are not specially considered.
The following referenced documents are indispensable for the application of this document.For datedreferences，only the edition cited applies. For undated references,the latest edition of the referenceddocument (including any amendments) applies.
EN ISO 4063, Welding and allied processes — Nomenclature of processes and reference numbers(lSO 4063:2009)
EN ISO 5817, Welding – Fusion-welded joints in steel,nickel,titanium and their alloys (beam weldingexcluded) — Quality levels for imperfections (ISo 5817:2003,corrected version:2005,including TechnicalCorrigendum 1:2006)
EN ISO 9692-1:2003,Welding and allied processes — Recommendations for joint preparation — Part 1:Manual metal-arc welding, gas-shielded metal-arc welding, gas welding,TIG welding and beam welding ofsteels (lso 9692-1:2003)
EN ISO 9692-2:1998, Welding and allied processes —Joint preparation — Part 2:Submerged arc welding ofsteels (so 9692-2:1998)
3.1Selection of detail
Connections are not considered to be equally suitable for all service conditions, nor is the order in which they are shown indicative of their relative characteristics. In selecting the appropriate detail to use from the several alternatives shown for each type of connection, consideration shall be given to existing fabrication and service conditions that pertain.
3.2 Joint preparation (geometry and size)
3.2.1 General The limitations quoted in weld profiles and sizes are based on commonly accepted practice, but they may be subjected to modifications if required by special welding techniques or design conditions, which should be included in the design documents and in the welding procedure specifications (WPS).
3.2.2 Joint preparation geometry Examples of recommended joint preparation geometry (e.g. bevel angles, root radius, presence of backing strips, root faces) are referred to EN ISO 9692-1 when applicable and to EN ISO 9692-2 relative to submerged arc welding process. Missing dimensions of preparations are in accordance with EN ISO 9692-1. In case where full penetration butt joints are indicated, it is intended that they shall be back chipped or gouged and back welded, or alternatively that the welding procedure shall be such as to ensure sound, effective root penetration. For relevant difference of thickness (generally a difference of about 3 mm (see Table 1, no. 1.1.1 to 1.1.6) could be considered relevant; in any case the thickness of material shall be taken into account, as well as the shape of the joint) of parts to be butt welded, the thickest element shall be shaped with a slope of 1:5 up to 1:2. Smoother transition of wall thickness is applicable in severe service conditions.
3.2.3 Weld sizes The thickness of welds (in particular of fillet welds), which are not determined by their profile, are based on the assumption that the connection need not be stronger than the connected parts.
The drawings of the nozzle and branch connections (see Tables 2 and 3) show a transversal section of the connection (see Figure 1) and a longitudinal section of the connection (see Figure 2).
3.4 Removal of internal sharp edges in branch bores It will be noted that the internal edges on the bores of branches are shown partially radiused (for example see Table 2, no. 2.1.6) because a stress concentration occurs at this point. The rounding of the edges is recommended when the branch connection is subjected to severe service conditions like fatigue, creep and stress corrosion.