Flow control device

摘要

A flow control device comprises an outer sleeve having an outer sleeve wall and at least one aperture through the outer sleeve wall; a inner sleeve having an inner sleeve wall and at least one aperture through the inner sleeve wall; and means for providing relative sliding movement of the sleeves between "open" positions allowing variable flow of fluid through the apertures of the sleeves and a "closed" position, so that relative movement of the sleeves produces available amount of opening through which fluid can flows. The apertures are arranged so that the change in the coefficient of velocity (CV) of fluid flowing through the apertures caused by a change in the relative displacement of the sleeves is substantially proportional to said change in relative displacement.