c. Position of welding.Approval tests are normally expected to be made in the most difficult positions that will be encountered in production welding. For example qualification in the vertical, horizontal and overhead positions usually qualifies for welding in the flat position.d. Testing of welder approval testpieces.All codes and specifications will have definite rules for the testing of approval welds to determine compliance. Most frequently this involves the removal of specimens for mechanical tests, such as bend tests, and specimens for macro examination from specific locations in the test pieces. Non-destructive testing may be required in conjunction with the mechanical tests.Other properties required of the procedure qualification welds such as tensile strength, hardness, etc. are not generally specified in welder approval tests since these properties depend primarily on the parent and filler materials used on procedure details that are beyond the individual welder's control.Welders whose test welds meet the requirements are qualified to use the process and to weld with the filler metals and procedures similar to those used in testing. It should be mentioned that a welder who has successfully welded a procedure test specimen is not required to undergo an approval test, unless the requirements of production welding are different from those of the procedure in which he has qualified.e. Re-tests.The circumstances for the re-testing of a welder include the following1. Failure of the initial test welds.2. A significant change in welding procedure.3. A welder has not been engaged in welding for an extended period. (Usually three months.)4. There is reason to question the welder's ability.5. Change of employment without the transfer of his approval certificates.CHECK LIST FOR WELDER AND PROCEDURE APPROVAL1. The test being carried out is the correct one required.2. Welders are in possession of all relevant information concerning the test.3. Test materials confirm in all respects to requirements.4. Joint configuration and tolerances are correct.5. Welding plant and consumables.6. The welder's identification is clearly marked on the testpiece.7. Where it is specified for a root run to be stopped and restarted in a certain position, that thisposition is clearly marked.8. In the case of joints welded in fixed positions the test piece is so fixed that it cannot be moved.9. All ancillary tools such as chipping hammers, wire brushes, grinders, etc. are available.