PISTON AS 7I1121 - Caterpillar

Illustration 16 g01210878
If the bowl surface does not align with the base edge and the bowl is lower than the top of the base edge, weld in a series dogs to the bowl and drive wedges under the dogs to bring the low points up flush as shown in Illustration 16. Remove any braces near the area to be realigned.Note: All K-series base edge assemblies other than the K80 base edge are butter beaded along the back edge and do not require preheating when welding the base edge into the bucket bowl. The K80 base edge assemblies are not butter beaded and do not require preheating prior to welding. The ends of all sizes of base edges are not butter beaded, but the K90 through K170 sized base edges should be preheated when welds are applied between the sidebars and the base edges. All base edges should be at room temperature before welding into the buckets. Base edge temperatures should not exceed 260 °C (500 °F) during welding.
Illustration 17 g01210924
Apply stringer weld (R) to the base edge bevel and bowl assembly. Start at the center of the edge and work toward the sides shown in Illustration 17.
Roll the bucket over and air arc the bottom side of the bowl at (S) to gain access to the bottom side of stringer weld (R) as shown in Illustration 17. Fill in the gouged area with multiple weld passes starting from the center and working toward the sides. If a wear plate is present, make the bevel weld equal to the thickness of the wear plate. Apply 8 mm (0.32 inch) fillet welds between the base edge and bowl assembly at (S) on the smaller base edges, increasing the fillet weld size up to 15 mm (0.59 inch) for the thickest base edges.
Roll the bucket back upright and fill in the rest of the bevel groove (R). Base edge bevels will range from 6 to 16 mm (0.24 to 0.63 inch) depending on the base edge thickness. Start from the center and work toward the sides. Fill in the bevel until the weld is flush with the bowl and the top of the base edge.Bucket Base Edge and Bowl Configurations
Illustration 18 g01211047
There a several basic variations in attaching the bowl to the rear of the base edge assembly. These variations are shown in Illustration 18. Base edge bowing and possible adapter weld cracking are reduced when thick wear plates are attached at the rear of the base edge as shown in Illustration (V) or when paddle plates are used with thicker base edge as shown in Illustration (W). Consider installing a paddle plate on the bucket 1520 mm (59.84 inch) or wider and for improved stiffness, add two to three gussets welded to the bottom of the bowl and plug welded to the paddle plate as shown in Illustration (X) .Preparing Sidebars when Welding Corner Adapters at the Corners
Perform Step 1 through Step 5 in ""Using K-series Center or Corner adapters at the Bucket