Abstract: A pressure reduction valve for a compressible fluid has an inlet and outlet separated by a pressure reduction member having a plurality of convergent-divergent nozzles High pressure gas or vapour passes from the valve inlet through the nozzles which control the expansion of the gas/vapour to a reduced pressure and eliminate shock waves. The gas/vapour expands into an intermediate attenuation chamber in which the resulting turbulence is confined before the gas/vapour passes through the diffuser into the outlet such that the diffused streams do not interact. The invention provides for pressure reduction with significantly reduced noise levels.