dearman1978,
A welder can have his performance qualified by mechanical tests of coupons cut from a sample pipe section, or by a radiograph of his first production weld (materials limited to P1 carbon steels). The mechanical test could be either tensile tests or bend test of the coupon / strap. The bend test of a strap involves bending the strap over a 1" mandrel or bar - easy enough for moderate coupon thickness. All this should be documented, and a log kept of the welder's work and weld specs / weld processes used for maintaining a record of current status of proficiency.
If materials are more exotic than carbon steel, then the radiography of first weld is not sufficient to qualify the welder. A mechanical test of weld coupon is required.
The B31 codes now accept a welder with current paperwork from another organzation to be qualified for welding with similar welding specification. The copies of the WPS/PQR record documents are to be obtained from the previous employer, compared, and signed off for acceptance of responsibilty. ASME B31.1 para 127.5.3