Codes, Standards and Certification Requirements
How codes and standards fit together
A code tells you what must be achieved; a standard often tells you how to test or qualify. Candidates must understand the difference between a specification (requirements for a product or procedure), a code (a body of rules with legal force when adopted), and a standard (a consensus document). Typical documents cited in welding inspection include AWS D1.1 for structural steel, ASME Section IX for procedure and performance qualification, and ISO 9606 for welder qualification. Know that a Welding Procedure Specification (WPS) is supported by a Procedure Qualification Record (PQR), and that a welder holds a performance qualification tested to a given standard.
Certification and qualification traps
Questions often blur procedure qualification with welder qualification: the first proves the procedure can produce a sound weld, the second proves the person can. Another trap is assuming a welder qualified on one process, position or thickness range is qualified for everything; qualification is always limited in range. Inspectors themselves are certified to schemes such as CWB, AWS or CSWIP, each with its own scope and renewal rules. Do not assume a certificate from one scheme satisfies another.
Worked example and rule of thumb
Suppose a WPS calls for 3 mm root gap and the welder uses 5 mm. The WPS is a qualified document; departing from an essential variable without requalification is a nonconformance. Rule of thumb: if a change could affect mechanical properties, treat it as essential until the code says otherwise. Always check that the WPS on the floor is the current revision, that the PQR supports it, and that each welder's certificate covers the process, position and thickness being welded. Record document numbers and revision status in your report; traceability is the point of the whole system.