A WPS is a document that describes how welding is to be carried out in production. They are recommended for all welding operations and many application codes and standards make them mandatory
What information should they include?
Sufficient details to enable any competent person to apply the information and produce a weld of acceptable quality. The amount of detail and level of controls specified on a WPS is dependant on the application and criticality of the joint to be welded.
For most applications the information required is generally similar to that recorded on a Procedure Qualification Record (PQR) or Welding Procedure Approval Record (WPAR), except that ranges are usually permitted on thicknesses, diameters, welding current, materials, joint types etc.
The purpose for qualification of a WPS is to determine
that the weldment proposed for construction is capable of
providing the required properties for its intended application.
Welding procedure qualification establishes the properties
of the weldment, not the skill of the welder or welding
operator.
The Procedure Qualification Record (PQR) documents
what occurred during welding the test coupon and the
results of testing of the coupon.
PQR's are not required if Standard Welding Procedures are used, see below for details.
This document contains details of the welding test, it must include details of all the parameters listed as variables in tables QW250 to QW265 for each process involved and all the destructive test results.
The relevant variables for each type of welding process are clearly defined in tables QW250 to QW265. The left hand column of each table defines the section and paragraph where each variable and its application to the table is explained in the code.
