Steam turbine seals are classified into blade seals, diaphragm seals, and shaft end seals based on their installation location.
Blade Seals
Blade seals include: Radial and axial seals between the moving blade shroud and the stationary blade or diaphragm, as well as radial and axial seals between the moving blade root and the stationary blade or diaphragm.
Diaphragm Seals
Diaphragm seals are used to limit steam leakage between stages between the inner surface of the diaphragm or the inner surface of the stationary blade ring and the outer surface of the rotor or hub.
Shaft End Seals
Shaft end seals are groups of seals installed at both ends of the rotor where it passes through the cylinder, suitable for different pressure drops; these are also called shaft seals.