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This document was prepared by Technical Committee ISO/TC 44, Welding and allied processes, Subcommittee SC 7, Representation and terms.
Any feedback, question or request for official interpretation related to any aspect of this document should be directed to the Secretariat of ISO/TC 44/SC 7 via your national standards body. A complete listing of these bodies can be found at www.iso.org/members.html. Official interpretations, where they exist, are available from this page: https://committee.iso.org/sites/tc44/home/interpretation.html.
This fifth edition cancels and replaces the fourth edition (ISO 2553:2013), which has been technically revised. The main changes compared to the previous edition are as follows:
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editorial corrections especially to align with other ISO/TC 44 standards and terminology;
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figures updated to more accurately reflect welds illustrated;
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plug welds in circular and elongated holes (slots) — clarification especially as it relates to slot welds;
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old Figure 5 is now shown as Table 5 for clarity;
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Clause 6 has been revised to reflect Pacific Rim practices.
Introduction
The symbols given in this document can be used on technical drawings for welded components. Design-related specifications, such as type, thickness, and length of weld, weld quality, surface treatment, filler material and testing specifications, can be indicated directly at the weld by means of the symbols. The principals of this document can be applied to brazed and soldered joints.
Clarity can be improved by references to collective information in the drawings or references to additional design-related documents.
Preparation for production can require detailed welding-related planning. The type of representation described in this document can be used for this purpose and complemented by additional production-related information (e.g. welding position, welding process, WPS, joint preparation, preheating). This information is often given in production-related documents, such as work schedules or welding procedure specifications (WPS).
Technical drawings are intended to clearly and understandably illustrate design-related specifications. Welding-related drawings are prepared and checked by specially trained personnel (see ISO 14731).
This document recognizes that there are two different approaches in the global market to designate the arrow side and other side on drawings, and allows for either to be used in isolation, to suit a particular market need. Application of either approach identifies a welding symbol in accordance with this document. The approach in accordance with system A is based on ISO 2553:19921. The approach in accordance with system B is based upon standards used by Pacific Rim countries.
INTERNATIONAL STANDARDISO 2553:2019 (E)
Welding and allied processes — Symbolic representation on drawings — Welded joints
1Scope
This document defines the rules to be applied for symbolic representation of welded joints on technical drawings. This can include information about the geometry, manufacture, quality and testing of the welds. The principles of this document can also be applied to soldered and brazed joints.
It is recognized that there are two different approaches in the global market to designate the arrow side and other side on drawings. In this document:
—
clauses, tables and figures which carry the suffix letter "A" are applicable only to the symbolic representation system based on a dual reference line;
—
clauses, tables and figures which carry the suffix letter "B" are applicable only to the symbolic representation system based on a single reference line;
—
clauses, tables and figures which do not have the suffix letter "A" or "B" are applicable to both systems.
The symbols shown in this document can be combined with other symbols used on technical drawings, for example to show surface finish requirements.
An alternative designation method is presented which can be used to represent welded joints on drawings by specifying essential design information such as weld dimensions, quality level, etc. The joint preparation and welding process(es) are then determined by the production unit in order to meet the specified requirements.
NOTE Examples given in this document, including dimensions, are illustrative only and are intended to demonstrate the proper application of principles.
2Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 128 (all parts), Technical drawings — General principles of presentation
ISO 129-1, Technical product documentation (TPD) — Presentation of dimensions and tolerances — Part 1: General principles
ISO 3098-2, Technical product documentation — Lettering — Part 2: Latin alphabet, numerals and marks
ISO 4063, Welding and allied processes — Nomenclature of processes and reference numbers
ISO/TR 25901 (all parts), Welding and related processes — Vocabulary
3Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/TR 25901 (all parts) and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
symbol consisting of an arrow line (3.3)and a reference line (3.4) and which can also include elementary symbols (3.8) and supplementary symbols (3.9), dimensions and/or tail, used on technical drawings
Note 1 to entry: See Clause 4.
3.2
basic welding symbol
symbol consisting of an arrow line (3.3), reference line (3.4) and tail used when the joint is not specified and only to indicate that a welded joint is to be made
Note 1 to entry: See 4.2.
3.3
arrow line
leader line used to indicate that the joint is to be welded generally drawn at 135° to the reference line (3.4)
Note 1 to entry: See 4.6.
3.4
reference line
part of the welding symbol (3.1) on which the elementary symbol (3.8) is located, generally drawn parallel to the bottom edge of the drawing
Note 1 to entry: See 4.7.
3.5
tail
V-shaped element added to the end of the continuous reference line (3.4) away from the arrow line (3.3)
Note 1 to entry: See 4.8.
3.6
arrow side
side of the joint to which the arrow line (3.3) is pointing
Note 1 to entry: See 4.7.2.1.
3.7
other side
opposite side of the joint to the arrow side (3.6)
Note 1 to entry: See 4.7.2.1.
3.8
elementary symbol
symbol forming part of the welding symbol (3.1) and drawn on the reference line (3.4) to indicate the type of weld and joint preparation
Note 1 to entry: See 4.4.
3.9
supplementary symbol
symbol used in conjunction with elementary symbols (3.8) to convey additional information about the joint
Note 1 to entry: See 4.5.
3.10
complementary information
non-symbolic information, relevant to the welds being made, which may be included in the tail (3.5) of the welding symbol (3.1)
Note 1 to entry: See 4.8.
3.11
intermittent weld
series of weld elements made at intervals along a joint
[SOURCE: ISO/TR 25901-1:2016, 2.1.6.15]
Note 1 to entry: See 5.3.2.
3.11.1
chain intermittent weld
intermittent weld (3.11) on each side of a joint arranged so that the weld elements lie opposite one another along the joint
Note 1 to entry: These are usually fillet welds in T-joints and lap joints.
Note 2 to entry: See 5.3.2.2.
[SOURCE: ISO/TR 25901-1:2016, 2.1.6.17, modified — Note 2 to entry has been adapted.]
3.11.2
staggered intermittent weld
intermittent weld (3.11) on each side of a joint arranged so that the weld elements on one side lie opposite the spaces on the other side (3.7) along the joint
Note 1 to entry: These are usually fillet welds in T-joints and lap joints.
Note 2 to entry: See 5.3.2.3.
[SOURCE: ISO/TR 25901-1:2016, 2.1.6.16, modified — Note 2 to entry has been adapted.]
3.12
offset
distance between the start of welding on one side of a staggeredintermittent weld (3.11.2) and the start of welding on the other side (3.7)
Note 1 to entry: See 5.3.2.3, C.2.3, Table C.1, No. 3, C.3.3 and Table C.2, No. 3.
3.13
back run
sealing run
final run deposited on the root side of a fusion weld
[SOURCE: ISO/TR 25901-1:2016, 2.1.8.21]
3.14
backing weld
backing in the form of a weld
3.15
nominal weld length
design length of a weld
Note 1 to entry: Nominal weld length is the length where the weld has its full size.
3.15.1
nominal length of weld element
<intermittent welds> nominal length of each element of the weld
Note 1 to entry: Nominal weld length is the length where the weld has its full size.
3.16
nominal throat thickness
a
design value of the height of the largest isosceles triangle that can be inscribed in the section of a fillet weld
Note 1 to entry: If other nominal throat thicknesses are specified, e.g. fillet welds with unequal leg lengths (see Table 6, No. 2.3), they need to be clearly specified. In these cases, the symbol a shall not be used.
[SOURCE: ISO/TR 25901-1:2016, 2.1.7.8, modified — The symbol a has been added. Note 1 to entry has been changed.]
3.17
leg length
z
distance from the actual or projected intersection of the fusion faces and the toe of a fillet weld, measured across the fusion face
[SOURCE: ISO/TR 25901-1:2016, 2.1.7.5, modified — The symbol z has been added.]
3.18
penetration depth
deposit thickness
weld metal thickness
thickness of the weld metal, excluding any reinforcement
[SOURCE: ISO/TR 25901-1:2016, 2.1.7.4]
3.19
deep penetration throat thickness
s
nominal throat thickness (3.16) or effective throat thickness to which a certain amount of fusion penetration is added
[SOURCE: ISO/TR 25901-1:2016, 2.1.7.9, modified — The symbol s has been added. Note 1 to entry has been deleted.]
3.20
flare-bevel weld
butt weld between a joint member with a curved surface and another with a planar surface
Note 1 to entry: See Table 6, No. 1.7.
[SOURCE: ISO/TR 25901-1:2016, 2.1.6.18]
3.21
flare-V weld
butt weld between two members with curved surfaces
Note 1 to entry: See Table 6, No. 1.6.
[SOURCE: ISO/TR 25901-1:2016, 2.1.6.19]
3.22
field weld
weld made outside workshops usually at the place of final installation
[SOURCE: ISO/TR 25901-1:2016, 2.1.8.40]
3.23
stake weld
weld in a T-joint where a laser beam or electron beam is irradiated from a horizontal plate/flange to vertical plate/web
Note 1 to entry: Vertical plates can be of different forms, such as corrugated panels and folded plates
Bibliography
[1]
ISO 1302, Geometrical Product Specifications (GPS) — Indication of surface texture in technical product documentation
[2]
ISO 2553:19922, Welded, brazed and soldered joints — Symbolic representation on drawings
[3]
ISO 5817, Welding — Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding excluded) — Quality levels for imperfections
[4]
ISO 6947, Welding and allied processes — Welding positions
[5]
ISO 9692 (all parts), Welding and allied processes — Types of joint preparation
[6]
ISO 10042, Welding — Arc-welded joints in aluminium and its alloys — Quality levels for imperfections
[7]
ISO 13919 (all parts), Welding — Electron and laser beam welded joints — Guidance on quality levels for imperfections
[8]
ISO 14171, Welding consumables — Solid wire electrodes, tubular cored electrodes and electrode/flux combinations for submerged arc welding of non alloy and fine grain steels — Classification
[9]
ISO 14341, Welding consumables — Wire electrodes and weld deposits for gas shielded metal arc welding of non alloy and fine grain steels — Classification
[10]
ISO 14731, Welding coordination — Tasks and responsibilities
[11]
ISO 17659, Welding — Multilingual terms for welded joints with illustrations
[12]
AWS A2.4:2012, Standard Symbols for Welding, Brazing, and Nondestructive Examination
[13]
AS 1101-3:2005, Graphical symbols for welding engineering — Part 3: Welding and non-destructive examination
[14]
JIS Z 3021:2016, Welding and allied processes — Symbolic representations
[15]
GregoryE. N., & ArmstrongA. A.Welding symbols on drawings, Abington, Cambridge: Woodhead Publishing Limited. ISBN 1-85573-589-X