Steam seal gap adjustment of turbine is one of the key procedures for turbine maintenance.The gap regulation speed directly affects the unit maintenance duration

and the adjustment results have an immediate influence on the unit economy.Four steam turbines for 350MW units in Nantong Power Plant were taken as the example to conduct the improvement of steam seal gap adjustment

on the premise of ensuring the unit maintenance quality.The concrete upgraded process is:regulating the steam seal gap by fully-installed cylinder tests combined with simulation;adjusting the steam seal radial clearance symmetrically;slightly regulating the high/medium pressure cylinder during assemble stage

changing the original maintenance result that the alignment deviation between cylinder and rotor was less than 0.15mm for that lifting the cylinder at steam turbine side for 0.20mm and that at the generator for 0.40mm.After adjustment

the unit rushed successfully for just one time

and the maintenance duration was dramatically shortened.