In-service inspection of steam turbine blades without disassembly
Loss of utility plant availability as a result of failure-causing cracks in steam turbine blades makes early detection of this problem critical. An Electric Power Research Institute survey, conducted as part of project RP 1266-24, indicated that 72% of turbine blade failures in fossil power plants occur in low-pressure (LP) turbines with half of all blade failures occurring in the last two blade stages (L-0 and L-1 rows). Failures are generally associated with blade tailing edges and root areas. Project RP 1266-24 also found that 79% of the blade problems in LP turbines were cracks. A turbine design of particular concern has been the Westinghouse Building Block (B.B.) 73. Reinhart and Associates has successfully inspected seven in-place B.B. 73 units for six utilities during the past 3 yr, as well as several disassembled turbines of other manufacturers and designs. These examinations consisted of visual and eddy-current examinations of the blade roots and trailing edges. The in-place inspections were performed using prototype manipulation devices to gain access to the blades through the hand holes. The only disassembly required to gain access for the examinations was the removal of the man-way covers on the main shell and the hand-hole covers on the outer cylinder covering the L-0 and L-1 blade rows.
- OSTI ID:
- 5579556
- Report Number(s):
- CONF-870837-
- Journal Information:
- Trans. Am. Nucl. Soc.; (United States), Journal Name: Trans. Am. Nucl. Soc.; (United States) Vol. 54; ISSN TANSA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
220200* -- Nuclear Reactor Technology-- Components & Accessories
AVAILABILITY
CRACKS
EDDY CURRENT TESTING
ELECTROMAGNETIC TESTING
EPRI
EQUIPMENT
FAILURES
FOSSIL-FUEL POWER PLANTS
IN-SERVICE INSPECTION
INSPECTION
MACHINERY
MATERIALS TESTING
NONDESTRUCTIVE TESTING
NUCLEAR FACILITIES
NUCLEAR POWER PLANTS
POWER PLANTS
REMOTE VIEWING EQUIPMENT
STEAM TURBINES
TESTING
THERMAL POWER PLANTS
TURBINES
TURBOMACHINERY