Pressure compounding in turbines

[1] The arrangement consists of a number of simple impulse turbines in series mounted on a common shaft.

The steam from the boiler passes through the first nozzle ring, where its pressure drops and velocity increases.

[2] The high-velocity jet steam is directed onto the first moving blades, wherein nearly all of its velocity is absorbed.

The process is repeated in the remaining rings until the whole of the pressure has been absorbed.

The effect of absorbing the pressure drop in stages is to reduce the velocity of the steam entering the moving blades.