Inspection of Steam Turbine MAN MARC2-C10 10 MW
Energetic machinery was called in for an overhaul on a Steam Turbine MAN MARC2-C10, 10 MW. During this inspection, several problems were found in the turbine. Steam leakages where observed at the split line of the casing at the level of the stuffing box DE side.
Figure 1: MAN MARC 2 10MW
Technical details:
- Type: MARC2-C10
- Year of construction: 2008
- Power: 4995kW
- Nominal speed: 10714 rpm
- Trip speed: 11785 rpm
Findings during inspections:
Energetic machinery was called in for an overhaul on a Steam Turbine MAN MARC2-C10, 10 MW. During this inspection, several problems were found in the turbine. Steam leakages where observed at the split line of the casing at the level of the stuffing box DE side.
Figure 2: Split line stuffing box damaged
We could also see that the rotor had made contact with the stator, damaging the seal strips on the rotor and on the carriers 1 and 2. The stuffing box DE side also showed some damages and the damping wire of the last row blades was broken.
Further inspection of the valve beams revealed damages on the valve sitting of the low pressure control valve.
Figure 3: Low pressure control valve beam
Figure 4: Control valve sitting damaged
Repair:
The machine was disassembled on site and was sent to our workshop in Stekene (BE) for further inspection and repair.
In our workshop, the valve beam was machined to remove all damages. Then by applying reverse engineering; 3D scanning, 3D modelling and 2D, all valve sittings were manufactured in our workshop. The produced parts were scrupulously controlled with high performance 3D inspection tools.
Figure 5: Valve beam machining
Figure 6: New valve sitting manufacturing
Figure 7: New control valve sittings assembled
Furthermore all regulating valves of the low pressure control valve were manufactured by applying reverse engineering.
Figure 8: New regulating valves manufactured
The damaged seal strips on the rotor and carriers were all removed and replaced.
Figure 9: Seal strips rotor replaced
Figure 10: Seal strip carriers replaced
The leakage problem at the split line was solved by welding the area of leakage and then machining the surface flat in our facility, then NDT was performed which revealed no cracks.
Figure 11: Welding split line
Figure 12: Split line machining
Figure 13: Split line repaired
With our knowledge of reverse engineering we created new 3D models of the stuffing boxes from the scan data of the old ones and the parts were produced in our facility. After production fast quality checks were performed on the new parts.
Figure 14: New stuffing boxes manufacturing
Figure 15: Quality check stuffing box
The broken damping wire of the last row blades was replaced, the balancing weight which was damaged was also manufactured and replaced, then the rotor was balanced at low speed in our workshop.
Figure 16: Rotor balancing
Other inspection activities:
Figure 17: Gearbox inspection
Figure 18: Inspection of radial tilting pad bearings
Figure 19: NDT of radial tilting pad bearings
Figure 20: Inspection of axial tilting pad bearings
Figure 21: NDT of radial tilting pad bearings
After a short down time, all repairs were performed and the rotor was reassembled with a successful startup and well running machine. Another satisfied customer whom we treat with great care.
*Energetic nv has no agreements or any relationship with the original equipment manufacturer