complete repair, overhauling, testing , replacement of damaged component of Main Inlet Valve of Unit No-I and successful commissioning at 3x1.5 MW Thirot Powerhouse under Resident Engineer, Larji Powerhouse Division HPSEBL Thalout.

The complete scope of work is as under: 1. Systematically disassemble the MIV housing, valve disc, shafts, and hydraulic servomotor at the Contractor’s Works and care should be taken to avoid any scratches or damage to mating parts during dismantling at works. 2. Measure all key dimensions (such as bore sizes, alignment, and clearances) using calibrated micrometres and dial gauges to identify exact wear patterns. 3. Inspect the badly damaged and eroded areas on the MIV body and disc. Grind or gouge out the damaged metal until clean, sound base metal is reached. 4. To prevent structural cracking and manage thermal stress, uniformly preheat the MIV body and disc casting before welding. Maintain this heat throughout the welding process in line with standard ASME procedures. 5. Build up the worn areas using high-quality, special alloy welding rods that match or exceed the strength of the original metal. Use careful welding techniques to keep residual stress as low as possible. 6. Set up the welded MIV body and disc on a boring or milling machine. Machine the parts back to their original dimensions. 7. Machine the valve seat and sealing faces to a smooth surface finish. The final sealing face must be completely smooth and entirely free from pinholes, blowholes, or tool marks. 8. Conduct a 100% liquid dye penetrant test on all welded and machined surfaces of both the body and disc. 9. The inspected surfaces must show zero cracks, pinholes, or surface defects. If any defects are found, they must be ground out and re-welded. 10. Repair all twelve (12) damaged, stripped, or cross-threaded structural bolt holes and replacement of SS Bolts on the Rubber Seal and SS Ring. 11. Replacement of Rubber Seal on the MIV as per the Sample/drawing. 12. Drill out and re-tap the holes to their original metric thread sizes. The finished threads must allow the matching bolts to be screwed in freely by hand without binding or excessive play. 13. Press out the two worn or damaged bronze bushings from both ends of the housing. Supply and machine two new end bushings made from high-grade, wear-resistant bronze. 14. Install the new bushings using a proper interference (tight) fit so they remain securely in place during operation. All the components shall be transported back to Thirot Power house and Commissioning of aforesaid detailed Overhauled/repaired components shall be carried out at site, ensuring that the MIV assebly and hydraulic servomotor are fully operational and meet the required performance standards, completing the job in all respects.