tailieunhanh - Machinery Components Maintenance And Repair Episode 2 Part 13

Tham khảo tài liệu 'machinery components maintenance and repair episode 2 part 13', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Protecting Machinery Parts Against Loss of Surface 615 Table 10-A-7 Specification for HVOF Repair of Centrifugal and Axial Compressors Steam Turbines High Speed Gear Shafts Generator Rotors Pump Elements Etc. Requirements 1. Base material shall be 4140 4330 4340 400 series stainless steel or 17-4 ASTM alloy steel composition. For other base alloys ask Praxair for details and comments. 2. Base material shall not exceed 40 RC hardness. 3. Total coating dimension of restored area shall not exceed parameters established for each coating type. It is recommended that buildup on bearing fits and other impact areas be limited to maximum diametral thickness. 4. When possible supply information regarding type of service operating speed temperature and pressure to which coating will be subjected also size tolerance TIR and out-of-round limitation. Process Recommended process es for repair of centrifugal gas compressor components and for gas or steam turbine components shall be the Tafa JP 5000 HVOF coating system. Note that no equivalent is acceptable. Parameters set forth by manufacturer and spin test results conducted by Praxair will determine coating requirements. Procedure 1. Part will be visually inspected and indicated for run-out and eccentricity condition upon receiving. 2. If required a magnetic particle inspection will be performed to check the part for cracks. The part shall be demagnetized after inspection to a residual level not to exceed 2 gauss. Stainless parts can be dye penetrant inspected. 3. Part will be ground undersize minimum per side to the maximum limit established per PST Coating Guideline 97 for each coating type and for each area designated to be repaired. Each edge of undercut region shall be provided with a suitable radius. When possible a substrate shoulder will be left at end of coated area. Author s Note Procedures may be generic or equipment-specific. Choose whichever ones give greatest assurance of achieving long-term component .