tailieunhanh - Pracrical Machinery Management for Process Plants P2

Major Process Equipment Maintenance and Repair If failed bearings are suspected in pump or motor: Check radial clearance and end float in motor. Run motor and check for abnormal noise, vibration. If motor is bad, remove and Pump and Seal Problems In the Shop While the pump is being repaired it is advisable to carefully examine every component. A recommended procedure is to match mark all parts prior to disassembly and to make the following checks while dismantling the pump: | 26 Major Process Equipment Maintenance and Repair If failed bearings are suspected in pump or motor Check radial clearance and end float in motor. Run motor and check for abnormal noise vibration If motor is bad remove and repair. Diagnosing Pump and Seal Problems In the Shop While the pump is being repaired it is advisable to carefully examine every component. A recommended procedure is to match mark all parts prior to disassembly and to make the following checks while dismantling the pump 1. Visually check impeller and nut for wear erosion corrosion and other deterioration. 2. Remove seal flange nuts and check seal tension. 3. Record impeller position in relation to pump frame. 4. Remove impeller nut and impeller. 5. Inspect wear rings inboard if any. 6. Check and record throttle bushing clearance. 7. Check body gasket faces. 8. Remove stuffing box body from pump frame. 9. Check stuffing box gasket face bore and pilots. 10. Remove and inspect all shaft keys. 11. Remove sleeve seal sleeve gasket and sleeve flange. If necessary determine the cause of seal failure and inspect condition of parts. 12. Check pump bearings for roughness. Record shaft end float check shaft for wear erosion corrosion and straightness. 13. Excessive shaft axial end play Excessive shaft movement can result in pitting fretting or wear at points of contact in shaft packing and mechanical seal areas. It can cause over or under-loading on springs resulting in high wear rates and leakage. It can also cause excessive strain and wear on pump bearings. Defective bearings in turn can cause excessive shaft end play. To check for this condition a dial indicator should be installed so that its stem bears against the shoulder on the shaft Figure 1-6 . Installation Maintenance and Repair of Horizontal Pumps 27 Figure 1-6. Checking for end play. Figure 1-7. Checking for bent shaft. A soft hammer should be used to lightly tap the shaft on one end and then the other. Total indicated end play should be .