Welder qualification test-WQT-ASME

Welder qualification test-WQT

The welder qualification test (WQT), is also known as a performance qualification. In the welder qualification test (WQT), the basic criteria established for welder qualification is to determine the welder’s ability to deposited sound weld metal.

The purpose of the welder qualification test (WQT) for the welding operator is to determine the welding operator’s mechanical and physical ability to operate the welding equipment. A welder qualification test (WQT) is recorded on documentation known as a test certificate that details range the welder is qualified.

 Welder-qualification-test-WQT

Welder qualification test (WQT) welding processes separately, with the essential variables that are applied to the welder and welding operator's performance qualifications. The welder qualifications are limited by the variables like essential variables, supplementary essential variables, and non-essential variables, that are given for each welding process are different variables, as Gas tungsten arc welding variable and shielded metal arc welding variable, etc.

Separate of their all essential variables for welder and all welding process listed in ASME SEC-IX,. The welding operator qualification is limited by the essential variables are for each type of weld (given below). A welder or welding operator may be qualified by volumetric NDE of a test coupon or their initial production weldings within the limitations of the welder (Given below) and welding operator (Given below) or by bend test taken from a test coupon that is given below.

The purpose of qualifying the person (welder), who shall use a joining process is to demonstrate that person's ability to produce a sound weld joint when using a welding procedure specification (WPS).

Welder performance Qualifications process.

Each organization is responsible for the supervision and control of material joining performed by persons for whom they have operational responsibility and control of all things. The organizations shall conduct the test required by the Section to qualify the performance of those persons with each joining process they shall use for the construction of components under the rules of the Codes, standards, and specifications that reference this Section. This requirement ensures that the qualifying organizations have determined that the personnel using its procedures are capable of achieving the minimum requirements specified for an acceptable joint limit. These responsibilities cannot be delegated to other organizations.

The welder certification process includes the following-

*Preparation of preliminary/primary welding procedure specification (WPS).

* Preparation of welding procedure specification (WPS) and procedure qualification record (PQR).

* Witness and certification of welder/welding procedure qualification by the client or third party authorized person.

* Non-destructive testing as per the AWSD1.1, ASME sec IX, BS EN codes.

* Destructive testing or mechanical testing (Tensile, bend test, macro examination, Charpy impact test, etc., as per code requirements) for PQR preparation as per the AWS D1.1, ASME SEC IX BS EN codes.

* Insurance of the third-party certification of welders and welder ID card.

Also Read:-Basic Criteria for Welder Qualification Welding Process as per Code API 1104

(a) The personnel who produce test joints for welder performance qualification shall be tested under the full supervision or authorized person and control of the qualifying organizations.

(b) The welder performance qualification test shall be performed following either a qualified welding procedure specification (WPS) or a welding standard procedure specification acceptable under the rules of the applicable Part for the joining process. The Part addressing any specific joining process may exempt portions of the welding procedure specification from being followed during the production of the welder performance qualification test (WPQT) coupon.

(c) Production of test joints under the supervision and controls of another organization is not permitted. It is permitted to subcontract of any or all of the work necessary for preparing the materials to be joined in the test joints, and the subsequent work for preparing test coupons from the completed test joint, and the performance of nondestructive test (NDT) examination and mechanical tests, provided the organization accepts full responsibilities for any such work.

(d) The welder performance qualification test (WPQT) may be terminated at any stage, whenever it becomes apparent to the supervisor conducting the tests that the person is tested does not have the required skills to produce satisfactory results.

(e) When a procedure qualification test/record (PQT/PQR) coupon has been tested and found acceptable, the person who prepared the test coupon is also qualified for the joining process used, within the ranges specified for welder performance qualification (WPQ/WQT) for the application processes.

(f) Authorized Persons who are successfully qualified shall be assigned an identifying number, letter, or symbol by the organizations, which shall be used to identify their work.

(g) If effective operational control of welder performance qualifications for two or more companies of different names exists under the same corporate ownership, the companies involved shall describe in their Quality Control System or Quality Assurance Program, the operational control of welder performance qualifications. In this case, the requalification of persons working within the companies of such organizations is not required, provided all other requirements of this Section are met.

WELDING VARIABLES FOR WELDING OPERATORS

GENERAL

A welding operator shall be requalified whenever a change is made in one of the following essential variables. There may be an exception or additional requirement for the processes of QW-362 and QW-363, and the special processes of the welder qualification.

Essential Variables — Automatic Welding.

(a) A change from automatic to manual machine welding.

(b) A change in the welding process.

(c) Automatic welding for electron beam and laser welding, the addition or deletion of filler metals. 

(d) For laser welding and hybrid welding using lasers, a change in laser type (e.g., change from CO2 to YAG). 

(e) Automatic welding for friction welding, a change from continuous drive to inertia welding, or vice-versa. 

(f) In automatic welding, for electron beam welding, a change from vacuum to out of vacuum equipment, and vice versa.

Essential Variables — Machine Welding. 

(a) A change in the welding process. 

(b) A change from direct visual controls to remote visual controls and vice‐versa of this. 

(c) The deletion of an automatic arc voltage control system for Gas tungsten arc welding (GTAW) variables. 

(d) The deletion of automatic joint tracking. 

(e) In the machine welding the addition of welding positions other than those already qualified.

(f) The deletion of consumables inserts, except that qualifications with consumable inserts that shall be also qualified for fillet welds and welds with backing. 

(g) The deletion of backing. Double weld groove welds are considered welding with backing. 

(h) A change from single-pass per side to multiples passes per side but not the reverse sides. 

(i) For hybrid plasma, gas metal arc welding (GMAW), the essential variable for welding operator qualification shall be in accordance with Table QW-357.

ELECTRON BEAM WELDING (EBW), LASER BEAM WELDING (LBW), HYBRID WELDING, AND FRICTION WELDING (FRW)

The welder performance qualification test coupon shall be production parts or test coupons that have joint designs permitted by any qualified WPS. The coupon shall be mechanically tested in accordance with table QW-452. Alternatively, when the part or coupon does not readily lend itself to the preparation of the bend test specimen, the part may be cut so that at least two full-thickness weld cross-sections are exposed. Those cross-sections shall be smoothed and etched with a suitable etchant to give a clear definition of the weld metal and heat-affected zone. The essentials variable for welding operators' qualifications shall be in accordance with QW-361.

STUD WELDING

Stud welding operators shall be performance qualified in accordance with the test requirements of QW-192.2 and the position requirements of QW-303.4

Welder limitations

Except for the special requirements (given below), each welder who welds under the rules of the Code shall have passed the mechanical and visual examinations. Alternatively, welders may be qualified by volumetric NDE per QW-191, when making a groove weld using Shielded metal arc welding (SMAW), SAW, Gas tungsten arc welding (GTAW), PAW, and GMAW (except short‐circuiting mode for radiographic examination) or a combination of these processes, except for P‐No. 21 through P‐No. 26, P‐No. 51 through P‐No. 53, and P‐No. 61 through P‐No. 62 metals. Welders making groove welds in P‐No. 21 through P‐No. 26 and P‐No. 51 through P‐No. 53 metals with the GTAW process may also be qualified by volumetric Nn destructive examination (NDE).

A welder qualified to weld in accordance with one qualified WPS is also qualified to weld in accordance with other qualified WPS, using the same welding process, within the limits of the essential variables.

Welders Examination

Welds made in test coupons for performance qualification may be examined by visual and mechanical examinations or by volumetric NDE for the process and mode of arc transfer specified in QW-304. Alternatively, a minimum of 50 mm length of the first production welds made by a welder using the process(es) and/or mode of arc transfer specified in QW-304 may be examined by volumetric non-destructive examination (NDE). 

(a) For pipes welded in the 5G, 6G, or special positions, the entire production weld circumference made by the welder shall be examined. 

(b) For small diameter pipe where the required minimum length of the weld cannot be obtained from a single production pipe circumference, additional consecutive circumferences of the same pipe diameter made by the welder shall be examined, except that the total number of circumferences need not exceed four. 

(c) The examination technique for the welder and acceptance criteria for production welds shall be in accordance with code QW-191.

QW-304.2 Failure to Meet Examination Standards. If the production of the weld is selected for welder performance qualification and it does not meet the examination of standards, the welder has failed the test. The entire production weld made by this welder shall be examined as per code requirement and repaired by a qualified welder or welding operator.

WELDING OPERATORS

Except for the special requirements of each and every welding operator who welds under the rules of this Code shall have passed the mechanical and visual examinations prescribed in the code QW-302.1 and code QW-302.4, respectively. Alternatively, welding operators may be qualified by volumetric non-destructive examinations (NDE) as per QW-191. When making a groove weld using shielded metal arc welding (SMAW), SAW, shielded metal arc welding (GTAW), PAW, EGW, and gas metal arc welding (GMAW) (except short‐circuiting mode for radiographic examination) or a combination of these processes, except for P‐No. 21 through P‐No. 26, P‐No. 51 through P‐No. 53, and P‐No. 61 through P‐No. 62 metals. Welding operators making groove welds in P‐No. 21 through P‐No. 26 and P‐No. 51 through P‐No. 53 metals with the gas tungsten arc welding (GTAW) process may also be qualified by volumetric non-destructive examination (NDE). The volumetric NDE shall be in accordance with QW-302.2. A welding operator or welder qualified to weld in accordance with one qualified welding procedure specification (WPS) is also qualified to weld in accordance with other qualified WPS within the limits of the essential variables of QW-360.

QW-305.1 Examination. Welds made in test coupons may be examined by volumetric NDE (QW-302.2) or by visual and mechanical examinations ( QW-302.1, QW-302.4). Alternatively, a minimum of 1 m length of the first production welds made entirely by the welding operator in accordance with a qualified WPS may be examined by volumetric NDE.

(a) For pipe welded in the 5G, 6G, and special positions, the entire production weld circumferences made by the welding operators shall be examined.

(b) For small diameter pipe where the required minimum length of the weld cannot be obtained from a single production pipe circumference, additional consecutive circumferences of the same pipe diameter made by the welding operator shall be examined except that the total number of circumferences need not exceed four.

(c) The welder examination technique and acceptance criteria for production welds shall be in accordance with the table QW-191. QW-305.2 Failure to Meet Examination Standards. If a portion of a production weld is selected for welding operators welder performance qualification (WPQ), and it is not meet the examination standards, the welding operator has failed the test. In this case, the entire production weld made by this welding operator shall be examined completely and repaired by a qualified welder or welding operator. In this case, alternatively, retests may be made as permitted in QW-320.

SPECIAL PROCESSES LIMITATION OF WELDER.

CORROSION-RESISTANT WELD METAL OVERLAY.

Qualification Test.

(a) The size of test coupons, limits of base metal thickness qualification, required examinations and tests, and test specimens shall be as specified in Table QW-453 (Welder qualification test thickness range link).

(b) Welders or welding operators who pass the tests for corrosion‐resistant weld metal overlay cladding shall only be qualified to apply corrosion‐resistant weld metal overlay portion of a groove weld joining composite clad or lined materials.

(c) The essential variables shall apply for welders and welding operators, respectively, except there is no limit on the maximum thickness of corrosion‐resistant overlay that may be applied in production. When specified as essential variables, the limitations of the position of welder and diameter qualified for groove welds that shall apply to overlay welds, except the limitations on the diameter of the pipe qualified shall apply only to welds deposited in the circumferential direction of the pipe.

Qualification on Composite Welds.

A welder or welding operator who has qualified on composite welds in clad or lined material, as provided in code QW-383.1(b) and it is also qualified to deposited corrosion‐resistant weld metal overlay.

Alternative Qualification With Groove Weld Tests.

When a chemical composition is not specified in the welding procedure specification (WPS), the welders, or welding operators who successfully complete a groove weld performance qualification test also called welder qualification test (WQT), and meeting the corrosion-resistant test overlay bend test requirements of QW-163 may be considered qualified for corrosion‐resistant overlay welding within the ranges defined in code QW-350 or code QW-360.

Here some addition of the above factors points shall be taken during the welder qualification test (WQT):

* Preheating and post-heating shall be as per the Welding Procedure Specification and the temperature shall be check before starting the welding of the test coupon. To check the temperature, the instrument can use a Pyrometer or Temperature chalk (Thermal chalk).

* Ampere and Voltage shall be maintained strictly as per the welding procedure specification (WPS), during the. The gauge which can measure the ampere and voltage is the Clamp meter.

* The Root run may be checked visually by using the Dye Penetrant Test method. The condition in which, if the welder qualifies the root pass then only he can be permitted for further welding for the welder qualification test (WQT).