Abstract: To prevent water to be entrapped in the lubrication oil and the oil to leak out from the oil baffle of steam turbine, the clean compressed air can be injected into oil baffle cavity of each bearing shell of the turbine, which flow in both direction of outer space and oil housing, preventing the oil to leak out and the steam to flow into the oil housing. The pressures of the compressed air of the adjustment valves at the inlet and outlet of each bearing shell were determined by detailed calculation of the compressed air flow needed for each bearing shell, the fluid resistance of each bearing shell and the resistance of backair pipe. The oil leakage from the oil baffles and entrapped water into the oil housings of the beating shells were eliminated, the safety operation of turbine in long period was ensured, and a lot of labor forces and material resources were saved due to adopting above mentioned measures.

Key words: oil baffle, pressure, pressure drop, pipe resistance