The ASME Boiler and Pressure Vessel Code (BPVC), Section IX contains qualification standards for the following;
* Welding, Brazing, and Fusing Processes
* Welder & Welding Operator
* Brazer and Brazing Operator
* Plastic fusing operator
Section IX is a reference document for the qualification of material manufacturing (welding, brazing, and plastic fusing) processes, which are used by various construction codes such as Sections I, III, IV, VIII, XII, etc.
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Note: The procedures involved in the various materials included in Section IX are;
* Welding
* Braze
* Plastic fusing
Also read,
ASME BPVC Section IX is divided into four parts, namely;
* Part QG: Common requirements for all materials include - involvement in the process (ie welding, brazing, and plastic fusing)
* Part QW: Includes requirements for welding
* Part QB: Includes requirements for brazing
* Part QF: Requirements for Plastic Fusing are included
Note: Part General Requirements and Part QF Plastic Fusing were added to the 2019 version of ASME Section IX.
Since our focus is on welding we will discuss only two parts, i.e. Part QG (General Requirements with a focus on the welding) and Part QW (Requirements for the Welding).
Also read,Part QW is further divided into five articles, these are;
Article 1. Welding - General Requirements for Welding
Article 2. Process Qualification for Welding
Article 3. Performance qualification for welders and welding operators
Article 4. Welding Data
Article 5. Standard Welding Process Specifications (SWPS)
These articles contain general references and guides that apply to positions such as welding process specification, process qualification and welder performance qualification, the type, and purpose of various mechanical tests, acceptance criteria, and applicability of Section IX.
We will discuss Part QG of ASME Section IX in this article:
Part QG gives general guidelines for the following;
QG 101: Process Specifications: There should be a process specification for each material joining process, these process specifications are called
Also Read,* Welding Process Specification - WPS (for welding)
* Brazing Process Specification - BPS (for brazing)
* Fusing Process Specification - FPS (for fusing)
The material or content of a process specification: The process specification i.e. a welding process specification (for welding) contains the parameters required to produce a sound weld in a value or range (as applicable) related to the welding process. These parameters are stated as variables by ASME. There are three types of variables;
* Essential variable
* Non-essential variable
* Complement required variable
Also Read,
Thickness range of welder qualification test (WQT)
Essential Variables (for WPS - QG-105.1 and QW-251.2): A change in the required variable is assumed to affect the mechanical properties (other than stiffness) of the welded joint. If the required variable is changed, the WPS will be required.
Supplementary Required Variables (QG-105.3 and QW-401.1): Changes in the Supplemental Required Variables will affect the joint, heat-affected area, or hardness properties of the base material. Therefore complementary essential variables become additional essential variables in situations where toughness tests are required for process qualification. When process eligibility does not require the addition of a hardness test, the complementary necessary variables are not applied.
Nonessential Variables (QG-105.4 & QW-251.3): Nonessential variables are those in which the current WPS can be altered without the need for it as it is not considered to affect the mechanical properties of the joint. Although WPS is not required for changes to non-variable variables, it must be properly addressed in the welding process specification (WPS).
QG 102: Procedure Qualification Record: A test coupon is welded based on the variables given in the proposed welding process specification (PWPS), then that test coupon is sent to the laboratory for destructive tests. After the satisfactory report of the destructive test, we state that the proposed welding process specification (PWPS) is qualified. This entire process of qualifying the proposed WPS is known as process qualification and complete data i.e. real-time data (or variables) that process qualification records (along with laboratory reports of destructive testing during welding of test coupons) PQR). ) Belongs to.
Required of procedure qualification
The purpose of qualifying the process specification is to prove that the proposed welding process is capable of producing weld joints with the necessary mechanical properties for intended applications.
The qualification of the proposed welding process specification (PWPS) demonstrates the mechanical properties of the welded joint, not the skills of the welder or welding operator.
The PQR will be produced to the authorized inspector whenever required. A welding process specification (WPS) may be supported by one or more PQR (s), and a process qualification record (PQR) may be used to support one or more welding process specification (s).
Content of a process qualification record (PQR)
Process Qualification Record (PQR) will include
* All real-time values (or range) of all required variables (mandatory) entered during the welding of the test coupon,
* Values of all non-essential variables entered during welding of test coupons
* During welding of test coupons, the values of the supplementary required variable (if testing is required) are recorded
* Welded Test Coupon Lab Test Report
QG 103: Performance qualification: Since, QG focuses on general requirements for welding, brazing, and plastic fusing. Therefore, it talks about performance qualification for all content joining processes. Welding, Brazing, and Plastic Fusing. But since our area of interest is welding only, this discussion is limited to welding only.
The performance qualification for a welder (or welding operator) is done to check the ability of the person to produce the sound weld.
QG 104: Performance Qualification Record: Mechanical test / non-destructive test report, as well as all real-time data observed during welding of test coupons, are referred to as documented qualification records. Whenever required, performance qualification records will be produced by the authorized inspector.
Also read,QG 105: Variables: The following variables are explained under this topic.
QG 105.1: Variables required for process specification
QG 105.2: Variables required for performance qualification
QG 105.3: Complement Required Variables
QG 105.4: Non-Required Variables
QG 105.5: Special Process Variables
QG 105.6: Applicability
QG 106: Organizational Responsibility: Three broad terms are discussed under this topic.
* Organizational Responsibility for Process Qualification (QG 106.1)
* Organizational Responsibility for Performance Qualification (QG 106.2)
* Simultaneous performance qualification (QG 106.3)
* The important points related to the responsibility of the organization are as follows;
QG 106.1: Organizational Responsibility for Process Qualification: The organization will be fully responsible for the qualification of its process specification. Welding of test coupons will be done entirely under the supervision and control of the qualifying organization and the person involved in this qualification process will be a direct employee of that organization or from an organization hired for welding services.
The following activities can be subcontracted, provided the organization accepts full responsibility, these are;
* Test coupon preparation
* Preparation of test specimens (after complete welding)
* Mechanical testing or destructive testing of those samples
Two or more companies with different names but operating under the same corporate ownership may use the Single Welding Process Specification (WPS), provided that all criteria of ASME Section IX have been met.
QG 106.2: Organizational Responsibility for Performance Qualification: The performance qualification test will be carried out only after the qualification of the welding process specification (WPS).
The person involved in the welding of the test coupon for the eligibility of the welding process specification (WPS) will be eligible for welding within the range specified for the performance qualification for that particular welding process.
Performance competency testing will be done under the full supervision and control of the organization. However, the following activities may be subcontinent;
* Test coupon preparation
* Preparation of test specimens (after complete welding)
* Mechanical testing or destructive testing of those samples
* A number/letter or symbol will be issued by the organization to successfully qualified welders (or welding operators) for identifiable purposes.
QG 106.3: Simultaneous performance qualification: Two or more different organizations can collectively participate in a union to qualify one or more welders and share information among themselves. During simultaneous performance eligibility, each participating organization will be represented by an employee of that organization designated responsible for that purpose.
Also read,QG 107: Ownership Transfer: When a new owner acquires an organization, a welding process specification (WPS), process qualification record (PQR), and a welder's performance record for that organization for the new owner (with certain conditions) Remains valid. Therefore there is no separate requirement.
QG 108: Qualifications for previous versions: The welding process specification (WPS), process qualification record (PQR), and welder's performance qualification will be valid with respect to any previous version of ASME Section IX and any modifications other than that. Not required by QW 420. However, qualifications for a new welding process specification and performance qualification shall be made in accordance with the latest version of ASME Section IX.
QG 109: Definitions: Several definitions related to welding are given in Part QG 109. These definitions can be found on the page number.
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