It is necessary to clearly understand the difference between the terms «attestation» and «certification» relating to testing for welders. When we say that the welder was certified, it means that this welder demonstrated the sufficient skills to perform the weld. At the same time, the concept of «certification» belongs to the documents which confirm this certification. The welder who has successfully passed the test for the certification program can be called the «attested welder» which differs from the «certified welder».
After the certification passing the welder is allowed to perform welding on production if in the welding technology does not include provisions, thicknesses, types of electrodes, etc., that are outside the scope of the certification. According to the majority of collections of regulations and rules, certification remains in force during the unlimited period of time if the welder continues to use successfully this technology in the process of welding works. However, if the welding inspector or other specialists in engineering supervision note unsatisfactory quality of work, the welder may need to undergo additional testing program for evaluation and/or additional training. If the welder leaves the employer and goes to work to other employer, the certification (the documentary confirmation of the attestation) can be cancelled. As each producer and the contractor bears responsibility for the attestation of the welders technologies, as a rule, the requirement about certification of the welder by each employer is provided in collections of regulations and rules.