What are the basic criteria for choosing the level of quality requirements?
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degree and importance of critical risk to product safety;
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production complexity;
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types of products that are manufactured;
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different materials types that are being used;
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degree of metallurgical problems that may occur;
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the degree to which manufacturing defects can affect product performance (e.g. misalignment, warping, welding defects).
What should a manufacturer consider when choosing the level of quality requirement for a particular application?
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To what extent is welding performed in the factory or on the construction site?
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How many welding procedures are applied in the company?
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How many different materials are welded in the company?
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Are these materials easily weldable?
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Is the production or fabrication specified by the standard?
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How critical are the conditions under which the components must operate?
Levels of quality requirements
EN ISO 3834-2 „Comprehensive quality requirements“ would be relevant for specialist welding contractors, where welding technology, materials and contract specifications differ from contract to contract and are technically demanding. Examples are companies that produce various equipment for power plants; equipment for the chemical, gas and oil industry; contracts with the military; equipment for the production and processing of iron and steel etc.
EN ISO 3834-3 „Standard quality requirements“ will be suitable in situations where the welding technology and materials used may be technically demanding, but the variety and type of products are not large. In this case, the welding contractor can be considered an expert in a narrow field. Examples are companies that manufacture a range of similar pressure vessels, standard pipes, small bridges and steel constructions.
EN ISO 3834-4 „Elementary quality requirements“ will be applied by companies that use welding as an auxiliary process that is not of the greatest importance for the general activity.Welding materials, procedures, designs, configurations and product capacities should be simple and much the same, with small requirements for frequent development of new products, procedures and control techniques. Typical application would be for example the manufacture of holders for electrical consoles and other equipment, agricultural equipment, guardrails, gratings, bumpers, pipes for heating and ventilation equipment etc.