Final answer:
A welder's qualification typically remains in effect as long as the welder continues welding without a break of more than six months. Employers must maintain records of the welder's work, and if there is a break in welding longer than six months, the certification may expire unless a continuity log has been kept.
Step-by-step explanation:
A welder's qualification, often referred to as Welder Certification, generally remains valid as long as the welder is consistently working within the scope of which they were tested. However, if a welder has not welded with the process they were qualified for within a period of six months, or if there is a specific reason to doubt the welder's abilities, requalification may be necessary. Furthermore, the specifics can vary based on the code under which they were certified, such as the American Welding Society (AWS) codes, ASME codes, or others.
For most certifications under AWS, for instance, as long as the welder continues welding without a break of more than six months, the qualification remains in effect. However, the employer is required to maintain records of the welder's work to ensure that they do not lapse. If a break in welding longer than six months occurs, the certification will expire unless a continuity log has been maintained.