Engineered Casting Repair Service, Inc.

Turbines

GE 227 MW Turbine, H/P and I/P Outer Cases

ECRS has was first contacted regarding this turbine in 1979. It was at this time that the original repairs were performed on the upper and lower, H/P and I/P cases. Because of the high operating pressure and temperature of these turbines, our repair material has a finite fatigue life. Because of this, the repairs need to be refurbished every 3-4 years. Work was performed on this particular unit during the 1979, 1981, 1984, 1991, and 1996 outages. The pictures that follow are of work performed during the 2001 outage. On the left is the existing repair, and on the right is after the refurbishing.

repair complete
ECRS has kept this damaged turbine in service for over 20 years, we will continue to do so for many years to come.

GE 250 MW Turbine, Upper and Lower I/P Outer Cases

survey of damages
Our engineer inspected 4 areas of cracking that were discovered in the I/P case of this unit. These cracks were located on the inside surfaces of both the upper and lower cases at four symmetrical areas. The cracking in this unit was "textbook" of that found in other similar units. At all 4 symmetrical locations of this I/P case, the cracking extended 3-4 feet around the inside wall from the horizontal joint. The cracking was present completely through the length of the stud holes and onto the outer surface at 3 of the 4 locations. This was evidence that these cracks were "through case cracks" with probable steam leakage.

repair procedures performed
The total length of crack in the upper and lower I/P cases was 242 inches. Over 70% of these cracks were completely through the case, and causing steam leakage. ECRS engineers designed an extensive crack repair involving metalocks®, preloaded masterlocks, keylocks, and metalace. The designs were specific to each of the 4 locations of cracking.

repair complete
After the installation of these repairs, the turbine was returned to service. There was zero steam leakage, and this turbine will remain in service for years to come.