Most fabricating codes and standards require qualification and certification of welding and
brazing procedures and personnel who perform these tasks. A Welding Procedure Specification (WPS) is a document
that provides in detail the required welding conditions for a specific application. WPS's are either qualified
by testing of pre-qualified, which means the WPS is exempt from procedure testing. If the WPS is qualified by
producing a representative sample, the procedure qualification test and welding parameters are documented in a
Procedure Qualification Record (PQR). The PQR test is tested by either a combination of nondestructive testing
and destructive testing or destructive testing alone. The specific requirements for procedure qualification testing
or the pre-qualified status are outlined in the specific code, standard or specification for which the production
work is being manufactured.
Pre-qualified welding procedures are permitted by some industry standards and codes. Under
this allowance, the employer of fabricator prepares in writing a welding procedure conforming to the specific requirements
of that governing code for materials, joint design, welding process, technique, etc. for the application. AWS D1.1 "Structural
Welding Code-Steel" has many joint details and welding processes which are classified as prequalified therefore the preparation
of the WPS for this application is a much simpler process than qualified by testing.