ASME Boiler and Pressure Vessel Code, Section IX-Welding, Brazing and Fusion Qualification

The ASME section IX specifies the requirements for the qualification of welder, welding operators, brazers, brazing operators and fusion operators and the procedure employed in welding, 0brazing and plastic fusing in accordance with the ASME boiler and pressure vessel code and the ASME code 31 for pressure piping and others codes and specifications. ASME section IX is referred by many construction code for the qualification for the metal joining processes. Some of constructions codes which refer ASME section IX are section I, III, IV, VIII, XI & XII and API 510 & API570. These construction codes are applied to specific types of fabrication and may impose additional requirements or exemptions to section IX requirements. Whenever the referencing Code, standard, or specification requires additional qualification requirements different than those given in Section IX, the requirements of the referencing Code, standard, or specification shall take superiority over the requirements of Section IX.

Purpose of Procedure Qualification: The purpose of the Procedure Qualification Record (PQR) is to ensure the material joining process to be used for construction of pressure vessel or piping is capable of producing joints having the required mechanical properties for the intended application. Personnel performing the material joining procedure qualification test shall be sufficiently skilled. The purpose of the procedure qualification test is to ensure the mechanical properties of the joint produced by the material joining process and not the skill of the personnel using the material joining process. When toughness testing is required by the construction code toughness supplementary variables also applies in addition to essential variables. The toughness supplementary essential variables do not apply unless referenced by the construction codes for toughness requirement.

Purpose of Performance Qualification: The purpose of welder Performance Qualification is to determine the ability of the person using a material joining process to produce a sound joint. In Operator Performance Qualification, the basic criterion is to determine the ability of the operator to properly operate the equipment to produce a sound joint.

Variables: Section IX defines variables for each welding process included for all material joining processes. Variables are the factors which have an effect upon the mechanical properties if defined for procedure qualification and an effect on the ability to make proper joints of welder/brazer if defined for the performance qualification.

Organization of ASME Section IX: Section IX id divided in four parts. i.e.

  1. Part QG: This part contains general requirements for the all material joining processes included in section IX.
  2. Part QW: This part contains requirements for the qualifications of the welding procedure and performance qualifications for each welding process included in section IX.
  3. Part QB: This part contains requirements for the qualifications of the brazing procedure and performance qualifications for brazing processes included in section IX.
  4.  Part QF: This part contains requirements for plastic fusing.

In this article we will only discuss about the Part QG and Part QW as we areconnected with welding and fabrication activities.

  • Part QG: Part QG contains the general requirement for the procedure and performance qualification for all the metal joining processes included in section IX. It defines the purpose of procedure and performance qualification which we have discussed earlier. This article specifies the record to be maintained for PQR’s and WPS’s. It further defines the essential variable for procedure and performance qualification and non-essential and supplementary variable for procedure qualification.

It specifies the qualification requirements for the personnel who will be performing supervising activities for qualification of procedure and performance qualification as per section IX. It specifies the responsibilities of the organization and the conditions to use procedure and performance qualifications by an organization. Further this part contains definitions for common terms used in the material joining processes.

  • Part QW Welding: This part addresses the requirements for the preparation of the Welding Procedure Qualifications (WPS), welding procedures, welder and welding operator qualification for manual, semi-automatic and machine welding processes defined in section IX. Part QW further divided in five articles as defined below
  1. Article I (Welding General Requirements): This part defines the purpose and responsibilities for welding procedure and performance qualifications for the processes defined in section IX. This part further addresses the different welding positions included for the plates and pipes for the test in groove and fillet weld test. This part defines the purpose of the different mechanical and non-destructive testing employed by section IX for the procedure and performance qualification and also addresses the location of specimen, procedure of testing and acceptance for the testing described in section IX for the all welding processes included in Section IX.
  1. Article II (Welding Procedure Qualifications): This article defines Welding Procedure Qualification (WPS) and Procedure Qualification Record (PQR). This article addresses the content, format and changes which can be made and revision criteria for the WPS, PQR. This articles further addresses how multiple WPS’s can be generated from single PQR and Single WPS from the multiple PQR’s and conditions for the combination of different WPS with different essential and supplementary essential variables to use on single production joint. Article II also addresses the mechanical testing required for the PQR qualifications, and the thickness qualification criteria for groove, fillet and partial penetration groove welds, stud welds and tube-to-tubesheet qualification. Further it defines the thickness qualification criteria in repair welds and dissimilar weld thicknesses in single joint. This article also defines the dimensions requirements of test coupon for the qualification of the each welding process and also for special welding processes (like weld-overlay and hybrid welding). In QW-250 welding variables are categorized as essential, supplementary essential and non-essential variables and further QW-252 to QW-267 addresses different variables applicable for different welding process included in section IX for qualifications of welding procedures.
  1. Article III (Welding Performance Qualifications): This article addresses the essential variables applicable for the welder and welding operator’s performance qualifications. It includes the test requirements, examinations to be done, records to be maintained and the minimum size to be tested to qualify a welder and welding operator’s performance qualifications. It also specifies retests required if welder fails to qualify in first attempt and expiration, revocation and renewal of welding performance qualifications for welder & welding operator. Essential variables for welders are addresses in QW-350 and for welding operators in QW-360.
  1. Article IV (Welding Data):  This article described the applicable essential, nonessential and supplementary essential variables for procedure qualifications as referenced in QW-250 for each welding processes and essential variables for performance qualification as referenced in QW-350 for each welding process.

This article also includes the base material grouping done “P-Number” wise for different materials to reduce the procedure and performance qualifications and alternate “P-Number” qualification for procedure and performance qualifications.

If further defines “F-Number”  grouping for different filler metal described in ASME section-II, based on their usability characteristics which determines the ability of welders to make satisfactory welds with a given filler metal. This grouping is done to reduce performance qualifications.

Further it gives qualifications ranges for thickness, welding positions as per variables defined for procedure and performance qualification for each process. QW-461 graphically defines all welding positions and gives qualifications limits of welding positions for each tested position. QW-462 gives the guidance in determining the dimensions of mechanical test specimens for test required for procedure and performance qualifications and QW-463 describes the location from where test specimens to be extracted from welded test coupon for procedure and performance qualifications.

  • Article V (Standard Welding Procedure Specifications) :  Standard welding procedure specifications (SWPSS) are the welding procedure specification, published by American Welding Society for the use of individual and  production welding companies without the need of further qualifications and use of limitations of these SWPSS are described in this article (Article V).This article defines the adoption and use of SWPSS in production welding.

We have defined the brief of section IX in this article and also included the brief of Part- QW welding part also. We can further share brief of other parts of section IX also, if you want us to describe any specific part please mention in comments we will try our best to come up with the same at the earliest.

Our Other articles you can visit for more information for welding and fabrication

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