DISTRIBUTOR 5354452 - Caterpillar

Image1.28.1
Refer to the D11 UT Inspection Areas section below for thickness and probe selection instructions for each weld joint. Table 1 shall be used for reference if needed. Alternate angles can be used for multiple thicknesses if warranted by joint design or joint preparation.
**Accept/Reject Criteria and Sizing**
Image1.30.1
Note: Adjacent discontinuities: when (AE) is smaller than the designated minimum length (AE)
Subsurface internal weld quality will meet the requirements set forth by this document. In order to determine the rejectable lengths of indications that meet or exceed the following thresholds:
1.) A -6dB offset shall be applied to any DAC or TCG. Indications that meet or exceed this offset threshold are rejectable.
2.) A +6dB Indication Rating for 0dB reference level shall apply. Indications that meet or exceed this indication rating are rejectable.
The above thresholds are created from 1.5mm (0.06 inch) SDH sensitivity reference point/s. These point/s are considered the reference level. The above sensitivity thresholds are created by reducing the rejectable indication size by 50% from the reference level.
An indication that meets or exceeds the -6dB offset threshold level for DAC or TCG OR a +6dB indications rating for 0dB reference level continuously for 12 mm (0.5 inch) or 17 mm (0.67 inch) aggregate length is rejectable.
Intermittent indications that do not meet the criteria but the aggregate length of the indications exceed 17mm (0.67 inch) of total length is considered rejectable. Indications below 5 mm (0.20 inch) in length are not typically included in the aggregate indication length.
In determining the ends of rejectable indications, the 6dB drop method shall be used, with the flaw detector sensitivity set to the reference level (0dB). Move the search unit parallel to the weld until the tip of the signal drops to 50% of the DAC height. Mark the weld even with the center of the search unit. Move the search unit parallel to the weld in the opposite direction until the signal drops to 50% of the DAC height. Mark the weld even with the center of the search unit. Acceptability of welds with multiple defective areas. If the space between two defective areas is less than the largest defect length, the area between the two defective areas shall be considered rejectable and should be marked for repair. Refer to Illustration 10.
**D11 UT Inspection Areas**
During In-Service Field Inspection: UT inspection is required on welds in Location A and B per Illustration 11. Both 45? and 70? send/receive conventional angle beam inspection. These methods are described below.
Image1.32.1
Image1.32.2
Image1.32.3
Inspect weld joints A and B (Illustration 11 / Image 1.32.1) with 45? and 70? send/receive transducer search units.
The Send/Receive transducer search units in both 45? and 70? shall be utilized for inspection. The transducers shall be scanned in both directions from the centerline of the weld where possible. Follow the Scan Pattern, Scan Distance, and Scan Speed and Accept/Reject Criteria and Sizing sections for determining if the welds are acceptable. The thickness of the instrument should be set to 75mm (3 inch) nominal rail thickness. The 70? should be