Abstract: The function of steam sealing is to reduce the steam leakage loss of turbine. The qualified labyrinth clearance can ensure the relative inner efficiency of turbine, smaller labyrinth clearance will influence on turbine safety operation, and bigger labyrinth clearance will reduce inner efficiency of turbine. In overhaul, the adjustment quality of labyrinth clearance is very important for turbine safety, economical operation. The traditional labyrinth clearance overhaul process has some defects which cause the qualification rate of labyrinth clearance to be lower. The test and adjustment methods of labyrinth clearance were improved, and which was helpful for unit safety and economical operation.

Key words: turbine, labyrinth clearance, measurement method, adjustment