Patent ID: 8545166

Claim:
A steam turbine system comprising: a high pressure (HP) turbine operatively coupled to an intermediate pressure (IP) turbine and a low pressure (LP) turbine; a working steam flow within at least one of the HP turbine, the IP turbine and the LP turbine; a leakoff path from a pressure packing in proximity to at least one of the HP turbine and the IP turbine, wherein leakoff steam flowing through the leakoff path is in fluid communication with the working steam flow within the steam turbine system; a plurality of steam seal lines from at least one of a pressure packing on the HP turbine and the IP turbine being fluidly connected to a seal steam header (SSH), wherein the SSH is fluidly connected to a vacuum packing on the LP turbine and is adapted to maintain constant self-sustaining sealing pressure on a seal packing of the LP turbine; means for restricting sealing steam flow operatively connected to at least one of the steam seal lines between HP turbine seal packing and the SSH and an IP turbine seal packing and the SSH; and a controller operatively connected to the means for restricting sealing steam flow and adapted to isolating excess sealing steam from the steam seal header, and wherein the means for restricting sealing steam flow are activated by the controller according to a pressure on the steam seal header according to a sequence of isolation sealing steam flow from of a HP inlet side, a HP outlet side, an IP inlet side, an IP outlet side, and a LP inlet side.