Coded Welder (EN ISO 9606) key terms

A welding condition that, if changed beyond the permitted range, invalidates the existing qualification and requires a new qualification test. Examples include process, material group, consumable, position and thickness.

The set of welding conditions and limits within which a qualified welder may work, derived from the variables of the test piece. Going outside these limits means the welder is not qualified for that work.

A practical test in which a candidate welds a specified test piece under defined conditions, which is then examined and tested to decide whether the welder is competent for the qualification sought.

The assembly of plates or pipes welded by the candidate during the qualification test, prepared and dimensioned according to the applicable standard for the chosen joint type and position.

The geometric configuration of the welded connection, such as butt joint, T-joint, corner joint or branch connection. The joint type welded in the test limits the joints the welder may subsequently produce.

A weld made between two members lying approximately in the same plane, joining them along their edges. Butt welds in test pieces are commonly subject to bend and radiographic testing.

A weld of roughly triangular cross-section joining two surfaces at an angle to each other, such as in a T-joint. Fillet weld tests are usually assessed by visual examination, fracture testing and macrosection.

The orientation of the weld axis and the workpiece relative to the welder, designated by codes such as PA, PB, PC, PD, PE, PF and PG. Position qualified in the test determines the positions permitted in production.

Welding in which the weld progresses upward on a vertical surface (position PF for pipe or equivalent plate position). It is generally considered more demanding and typically qualifies a wider range of positions.

The limits of base material and deposited weld thickness for which a welder is qualified, derived from the thickness of the test piece and the process used, as defined in the standard's tables.

A classification of base materials by metallurgical type and mechanical properties, such as carbon steel, stainless steel, aluminium and copper alloys. Changing to a different group usually requires separate qualification.

The parent metal being joined by welding. Its group, thickness and condition are essential variables that define what a welder is qualified to weld.

The filler material used in welding, such as covered electrode, solid wire, flux-cored wire or rod. The consumable type and its grouping affect the validity of a welder's qualification.

A gas or gas mixture supplied around the arc to protect the molten weld pool from atmospheric contamination. A change between active and inert gas types is normally an essential variable.

The numeric code for manual metal arc welding with a covered electrode, also called stick welding. The welder controls the arc and electrode manually while the coating provides shielding and slag.

The numeric code for metal active gas welding with a solid wire electrode, a semi-automatic process using an active shielding gas. The wire is fed continuously and the arc is shielded by the gas.

The numeric code for tungsten inert gas welding, also called TIG, where the arc is struck between a non-consumable tungsten electrode and the work under inert gas shielding, with filler added separately if required.

The numeric code for oxy-fuel gas welding, in which the heat for melting comes from a fuel gas flame rather than an electric arc. It is used mainly for thinner materials and specific applications.

The specific method by which coalescence is achieved, identified by a numeric designation in the standard. A change of process is an essential variable requiring separate qualification.

A competent person responsible for supervising the qualification test, examining the test pieces and evaluating results against the acceptance criteria, and for signing the relevant records.

Inspection of the completed test piece by eye, with or without magnification, to detect surface imperfections such as cracks, porosity, undercut and incomplete fusion before further testing.

A volumetric non-destructive method using X-rays or gamma rays to reveal internal imperfections in a butt weld, producing an image assessed against the standard's acceptance levels.

A destructive test in which a transverse specimen cut from a butt weld is bent through a specified angle to reveal surface and near-surface imperfections on the tension side of the bend.

A destructive test, often used for fillet welds, in which the test piece is broken open to expose the weld root and throat so imperfections such as lack of fusion or penetration can be seen.

A cross-section cut from a weld, polished and etched to reveal the weld profile and internal imperfections. It is used to assess penetration, fusion, throat thickness and leg length against criteria.

The specified limits for imperfections and test results that a test piece must meet for the welder to be qualified. Results outside these limits lead to failure of the test.

The time during which a welder's qualification remains valid, typically two years, provided the qualification is confirmed at defined intervals and the welder works within the qualified range.

The periodic check, normally every six months, by the employer or responsible person that the welder has been continuously working within the qualified range, allowing the qualification to remain valid.

The process of extending a qualification that has expired or lapsed, either by a satisfactory re-test or by other means permitted by the standard, such as documented evidence of continued satisfactory work.

The document recording the details of a welder's qualification test, including essential variables, test results and the ranges qualified, signed by the examiner and retained by the employer.

The formal document issued to a welder confirming the qualification achieved, stating the process, position, thickness and other ranges qualified, together with the validity period and issuing body.

A document cited in the standard whose provisions must be applied for the standard to be used correctly, for example standards for testing methods or consumable classification.

A short weld used to hold parts of the test assembly in alignment before the main weld is made. Tacks are normally consumed by the main weld and must be sound and clean.

The first run deposited in a joint, forming the weld root. Its quality is critical and root imperfections are commonly assessed by radiographic or bend testing.

Material, such as a backing strip or backing weld, placed behind the joint root to support the molten pool. Its use may be recorded as a variable affecting the qualification.

A document providing the required welding variables for a specific application to assure repeatability by properly trained welders. Qualification tests are performed to a WPS.

Items worn to protect the welder from hazards, including welding helmet with filter, flame-resistant clothing, gloves, apron and safety footwear. Its correct use is required during qualification testing.

Local exhaust ventilation or other means used to remove welding fumes and gases from the welder's breathing zone, protecting against respiratory harm during welding and testing.