ISO 3834 Welding Standard
Why ISO 3834?
Processes such as fusion welding are widely used to manufacture many products. In some companies, they are the key feature of production. Products may range from simple to complex. Examples include pressure vessels, domestic and agricultural equipment, cranes, bridges, transport vehicles and other items.
These processes exert a profound influence on the cost of manufacture and quality of the product. It is important, therefore, to ensure that these processes are carried out in the most effective way and that appropriate control is exercised over all aspects of the operation.
It is emphasised that ISO 3834 is not a quality management system standard replacing ISO 9001:2015. However, it can be a useful tool when ISO 9001:2000 is applied by manufacturers.
Specification of quality requirements for welding processes is important because the quality of these processes cannot be readily verified. Therefore, they are considered to be special processes as noted by ISO 9000:2015.
Quality cannot be inspected into a product; it has to be built in. Even the most extensive and sophisticated non-destructive testing does not improve the quality of the product.
For products to be free from serious problems in production and in service, it is necessary to provide controls, from the design phase, through material selection, into manufacture and subsequent inspection. For example, poor design may create serious and costly difficulties in the workshop, on site, or in service. Incorrect material selection may result in problems, such as cracking in welded joints.
To ensure sound and effective manufacturing, management needs to understand and appreciate the sources of potential trouble and to implement appropriate procedures for their control.
ISO 3834 identifies measures that are applicable for different situations. Typically, they may be applied in the following circumstances:
- in contractual situations: specification of welding quality requirements
- by manufacturers: establishment and maintenance of welding quality requirements
ISO 3834 has 3 levels and ISO 3834-2, ISO 3834-3 and ISO 3834-4 provide complete sets of quality requirements for process control related to all fusion welding processes.
Requirements: ISO 3834
Selection of the appropriate level of quality requirements
The selection of the appropriate part of ISO 3834, specifying the required level of quality requirements, should be in accordance with the product standard, specification, regulation or contract. Because ISO 3834 may be used in a variety of situations and for different applications, definitive rules on the level of quality requirements to be adopted in individual circumstances cannot be given in this clause.
ISO 3834 may be applied in a variety of situations. The manufacturer should select one of the three parts specifying different levels of quality requirements, based on the following criteria related to products:
- the extent and significance of safety-critical products
- the complexity of manufacture
- the range of products manufactured
- the range of different materials used
- the extent to which metallurgical problems may occur
- the extent to which manufacturing imperfections, e.g. misalignment, distortion or weld imperfection, affect product performance