Items that can be changed without re-qualification (e.g., joint design, shielding gas flow rate in some cases). 2. Procedure Qualification Record (PQR)
ASME classifies welding variables into three distinct categories. Understanding these classifications is critical because a change in certain variables can void a qualification, requiring a complete retest.
To successfully execute an ASME-compliant weld, Section IX mandates a strict three-step documentation and qualification lifecycle: the Welding Procedure Specification (WPS), the Procedure Qualification Record (PQR), and the Welder Performance Qualification (WPQ). Core Documentation Requirements 1. Welding Procedure Specification (WPS)
Carbon-manganese or low-carbon steels (most common industrial steels). P-No. 8: Austenitic stainless steels (e.g., 304, 316). welding standard asme
ASME assigns P-Numbers to base metals based on composition, weldability, and mechanical properties. For example, P-Number 1 represents carbon steels, while P-Number 8 covers austenitic stainless steels. If a manufacturer qualifies a procedure using a specific P-Number 1 steel, that procedure generally qualifies them to weld all other steels within the P-Number 1 designation, saving significant testing costs. F-Numbers (Filler Metals)
A record of the welding variables used to produce an actual test weldment and the results of the tests conducted to qualify the WPS.
The WPS is a written document that acts as a recipe for a successful weld. It provides direction to the welder to ensure the weld meets all code requirements. A WPS lists all variables—such as base metals, filler metals, shielding gas, preheat temperatures, and welding techniques—that must be followed during production. Procedure Qualification Record (PQR) Items that can be changed without re-qualification (e
This standard applies to piping systems in power plants, industrial facilities, and institutional buildings. It requires that all welding be performed using qualified procedures and welders per ASME Section IX. Recent updates have introduced more stringent requirements for advanced materials like P91 and P92, focusing on microstructural integrity and post-weld heat treatment.
To learn more about industrial standards and engineering protocols, you can consult the official ASME Boiler and Pressure Vessel Code guidelines. For structural guidelines that operate alongside pressure systems, the AWS D1.1 structural steel manual offers a parallel framework for non-pressurized components. If you are tracking welder qualifications globally, reviewing the ISO 9606 qualification framework provides insights into European and international welding standards.
To fully understand the ASME welding standard, one must first understand the broader structure of the BPVC. The Code is divided into several sections, each addressing a specific aspect of boiler and pressure vessel construction. The key sections that relate most directly to welding include: That requires a new PQR.
The WPS is a written blueprint that provides direction to the welder for making production welds in accordance with Code requirements. It outlines the specific parameters required for a given application, including base metals, filler metals, preheat temperatures, shielding gas, and electrical characteristics. 2. Procedure Qualification Record (PQR)
A PQR qualifies a thickness range . For example, welding a 0.5-inch plate qualifies you for 0.125 to 1 inch. Welding a 2-inch plate? That requires a new PQR.