tailieunhanh - Machinery Component Maintenance and Repair Part 13

Tham khảo tài liệu 'machinery component maintenance and repair part 13', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 470 Machinery Component Maintenance and Repair Figure 8-19. Impeller with direct Stellite overlay in final machined condition. As mentioned previously an important part of the procedure is to limit the heat input particularly during the buildup of the shoulder using SMAW electrodes. If this is not controlled distortion of the impeller shrouds can occur. In order to prevent this Vs-in diameter electrodes a stringer bead technique and a maximum interpass temperature of 350 F are specified. 2. Water Injection Pump Case Due to a combination of the water chemistry and the pump design the carbon steel pump cases were experiencing interstage leakage due to erosion corrosion under the case wear rings and along the case split line faces. The repair procedure developed consists of undercutting 1 s in. deep the centerline bore and the inner periphery of the split line face. These areas are overlaid with Inconel 182 AWS ENiCrFe-3 . After rough machining the cases are stress relieved and then machined to final dimensions Figures 8-20 and 8-21 . The erosion corrosion problem has been effectively eliminated while providing a significant savings compared to the cost of a stainless or alloy replacement case. Repair and Maintenance of Rotating Equipment Components 471 Figure 8-20. Pump case with overlay along centerline bore and edge of split line face. Figure 8-21. Close-up of pump case overlay in the partially machined condition. 472 Machinery Component Maintenance and Repair 3. Seal Flanges The Monel seal flanges glands on a water injection pump were experiencing pitting corrosion on the sealing faces. A localized overlay using Inconel 625 Figure 8-22 has eliminated the problem. 4. Impeller Wear Rings Prior to the decision to hardface directly on the impeller attempts were made to fabricate replacement wear rings. The first attempts used core billets as raw stock however it appears easier to use solid bar stock. The OD is overlaid before drilling the center bore. Unsolved .