| 摘要 |
The invention provides a fluid flow control valve (60) comprising a cylindrical inlet chamber (61) having a fluid inlet aperture (62) and a coaxial, optionally but preferably waisted, cylindrical outlet chamber (63) having a fluid outlet aperture (64), said inlet chamber containing adjacent first and a second apertured members (68, 69) mutually rotatable between a position in which fluid flow from said inlet aperture to said outlet aperture is permitted and a position in which said flow is prevented or constrained, characterised in that the apertures (67, 70) in at least one of said members are aligned so as to provide fluid flowing therethrough with a velocity component tangential to the axis of said outlet chamber. |
