AWS C3.4:2016

This specification presents the minimum fabrication, equipment, and process procedure requirements, as well as inspection requirements for the torch brazing of steels, stainless steels, copper, copper alloys, and heat- or corrosion-resistant alloys and other materials that can be adequately torch brazed (the torch brazing of aluminum alloys is addressed in AWS C3.7M/C3.7, Specification for Aluminum Brazing). This specification provides criteria for classifying torch brazed joints based on loading and the consequences of failure and quality assurance criteria defining the limits of acceptability in each class. The specification defines acceptable torch brazing equipment, materials, and procedures as well as the required inspection for each class of joint.
Scope : 1.1 Scope. This specification presents the minimum fabrication and quality requirements for the torch brazing of materials such as steels, stainless steels, copper, copper alloys, and heat- and corrosion-resistant alloys as well as other materials that can be adequately torch brazed. Note that the torch brazing of aluminum alloys is addressed in AWS C3.7M/C3.7, Specification for Aluminum Brazing. The purpose of this specification is to standardize torch brazing process requirements and brazed joint quality requirements for all applications requiring brazed joints of assured quality. This document establishes minimum requirements for processes and products with a minimum of explanatory information so that sources of ambiguity are minimized. It assigns responsibility for the ultimate quality of the brazed product to a single organization and permits that organization to modify requirements if appropriate to the application. It requires proper documentation of any such modifications. 1.2 Units of Measurement. This standard makes use of both the International System of Units (SI) and U.S. Customary Units; the latter are shown within brackets [ ]. The measurements may not be exact equivalents; therefore, each system must be used independently. 1.3 Safety. Safety and health issues and concerns are beyond the scope of this standard; some safety and health information is provided, but such issues are not fully addressed herein. Safety and Health information is available from the following sources: American Welding Society: (1) ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes (2) AWS Safety and Health Fact Sheets (3) Other safety and health information on the AWS website Material or Equipment Manufacturers: (1) Safety Data Sheets supplied by the materials manufacturers (2) Operating Manuals supplied by equipment manufacturers Applicable Regulatory Agencies: (1) United States Department of Labor, Occupational Safety & Health Administration (OSHA) (2) Equivalent agencies of other countries and individual states Work performed in accordance with this standard may involve the use of materials that have been deemed hazardous, and may involve operations or equipment that may cause injury or death. This standard does not purport to address all safety and health risks that may be encountered. The user of this standard should establish an appropriate safety program to address such risks as well as to meet applicable regulatory requirements. ANSI Z49.1 should be considered when developing the safety program. See 5.6 for additional safety and health information. 1.4 Ordering Information. The purchaser shall provide the following information to the brazer:1) Parent metal alloy and condition2) Brazing Filler Metal The following information is optional or has default requirements in this document; therefore, the purchaser may specify alternate requirements: 1) Brazed joint classification (Clause 4) 2) Cosmetic criteria 3) Fillet size 4) Areas to be free of excess brazing filler metal 5) Flux type or restrictions on use of flux 6) Heating or cooling rates 7) Post braze heat treatment8) Pre- or post braze cleaning methods 9) Method of nondestructive examination 10) Name of the Organization Having Quality Responsibility 11) Part number and quantity of parts