Multiple turbines
It is a simple matter to design and link multiple turbines to the same shaft to optimise power output. The safety, economical and environmental advantages of the basic design transfers to multiple stage units equally well.
The design also lends itself to staged pressure letdown where each turbine in the stage operates on a progressively lower pressure drop. This method has limitations in respect of freezing and may require the removal of water vapour or re-heating of the gas.