dokument, mis sisaldab keevitusprotseduuri nõutud muutujaid ja mis tuleb kvalifitseerida; keevitusprotseduuri spetsifikaadi heakskiiduks vajalike proovikehade keevitamine toimub pWPS alusel (vt keevitusprotseduur), document containing the required variables of the welding procedure which has to be qualified; the preliminary procedure specifies how a qualification test piece is to be welded including the types of materials, type of weld configuration, test piece size, welding processes to be used, welding consumables to be used and all the necessary welding parameters (see: welding procedure specification)