API 1104:2005 pdf download

API 1104:2005 pdf download.Welding of Pipelines and Related Facilities.
If any of the following essential variables are changed in a procedure specification, the welder using the new procedure shall he requalified:
a. A change from one welding process to another welding process or combination of processes, as follows:
1. A change from one welding process to a different welding process; or
2. A change in the combination of welding processes, unless the welder has qualified on separate qualification tests, each using the same welding process that is used for the combination of welding processes.
b. A change in the direction of welding from vertical uphill to vertical downhill, or vice versa.
c. A change of filler-metal classification from Group 1 or 2 to Group 3 or from Group 3 to Group 1 or 2 (see Table 1).
6.4 VISUAL EXAMINATION
For a qualification test weld to meet the requirements for visual examination, the weld shall he free from cracks, inadequate penetration, and burn-through, and must present a neat workman-like appearance. The depth of undercutting adjacent to the final bead on the outside of the pipe shall not he more than ‘/32 in. (0.8 mm) or 12.5% of the pipe wall thickness, whichever is smaller, and there shall not be more than 2 in. (50 mm) of undercutting in any continuous 12 in. (300 mm) length of weld.
When semi-automatic or mechanized welding is used, filler wire protruding into the inside of the pipe shall be kept to a minimum.
Failure to meet the requirements of this subsection shall he adequate cause to eliminate additional testing.
6.5 DESTRUCTIVE TESTING
6.5.1 Sampling of Test Butt Welds
To test butt welds, samples shall he cut from each test weld. Figure 12 shows the locations from which the specimens are to he removed if the test weld is a complete circumferential weld. If the test weld consists of segments of pipe nipples. an approximately equal number of specimens shall he removed from each segment. The total number of specimens and the tests to which each shall be submitted are shown in Table 3. The specimens shall be air cooled to ambient temperature prior to testing. For pipe with an outside diameter less than or equal to 1.315 in. (33.4 mm), one full- pipe section specimen may he substituted for the root-bend and Nick-break sped mens. This ful 1-section specimen shall he tested in accordance with 5.6.2.2 and shall meet the requirements of 6.5.3.
6.5.2 Tensile-strength, Nick-break, and Bend-test Procedures for Butt Welds
The specimens shall he prepared for tensile-strength, Nick- break and bend tests, and the tests shall he performed as described in 5.6. However, for the purpose of welder qualification, it is not necessary to calculate the tensile strength of the coupons. The tensile strength test may even be omitted, in which case the specimens designated for the test shall be subjected to the Nick-break test.
6.5.3 Tensile-strength Test Requirements for Butt Welds
For the tensile-strength test, ii any of the reduced-section specimens or the full-section specimen breaks in the weld or at the junction of the weld and the parent material and fails to meet the soundness requirements of 5.6.3.3, the welder shall be disqualified.
6.5.4 Nick-breakTest Requirements for Butt Welds
For the Nick-break test, if any specimen shows imperfections that exceed those allowed by 5.6.3.3, the welder shall be disqualified.
6.5.5 Bend Test Requirements for Butt Welds
For the bend tests, if any specimen shows imperfections that exceed those allowed by 5.6.4.3 or 5.6.5.3, the welder shall be disqualified. Welds in high-test pipe may not bend to the full U shape. These welds shall be considered acceptable if the specimens that crack are broken apart and their exposed surfaces meet the requirements of 5.6.3.3.
If one of the bend test specimens fails to meet these requirements and, in the company’s opinion, the imperfection observed is not representative of the weld, the test specimen may be replaced by an additional specimen cut adjacent to the one that failed. The welder shall he disqualified if the additional specimen also shows imperfections that exceed the specified limits.
6.5.6 Sampling of Test Fillet Welds
To test fillet welds, specimens shall be cut from each test weld. Figure 10 shows the locations from which the specimens are to be removed if the test weld is a complete circumferential weld. If the test weld consists of segments of pipe nipples, an approximately equal number of specimens shall be removed from each segment. The specimens shall be air cooled to ambient temperature prior to testing.