DOUBLE CASING TURBINE WITH AT LEAST ONE VALVE FOR THE HORIZONTAL SUPPLY OF STEAM

摘要

The valve intended for direct connection to the outer casing of a double casing steam turbine has a diffusor located in the valve housing, which diffusor protrudes through the outer casing into a connection stub pipe of the inner casing, where it is connected with a flexible seal to the inner casing. In a preferred embodiment, the diffusor sits with a cylindrical step in a corresponding bore of the valve housing, the valve housing consisting of ferritic cast material and the diffusor of austenitic steel, whose coefficient of thermal expansion is greater than that of the valve housing material. The diffusor, which sits loosely in the cold condition, expands more than the valve housing when the turbine becomes hot so that the diffusor is then firmly held in the valve housing.