Abstract: A flow restrictor device for production tubing comprising an obstructing member. The flow restrictor is arranged for movement between a first position where the obstructing member is located so as to form a seal with an edge of an aperture formed in a wall of said production tubing and is arranged to prevent fluid flow through said aperture, and a second position where the obstructing member is located so that the aperture is unobstructed. The flow restrictor further comprises a retaining arrangement for restricting possible locations of said obstructing member to said first position, second position and positions therebetween. The aperture allows fluid communication between the exterior and interior of the production tubing.

Abstract: The present invention provides a flow restrictor coupling (10) and a method of forming a flow restrictor coupling. The flow restrictor coupling (10) comprises a hollow tubular member (12) having at a first end thereof first means for engagement with an end of a first pipe and, at a second end thereof, second means for engagement with an end of a second pipe, wherein said hollow tubular member (12) is arranged to couple said first pipe to said second pipe and to provide for fluid communication therebetween, said flow restrictor coupling (10) further being arranged to present at least one aperture (26) in a wall of said hollow tubular member between said first and second ends, the aperture (26) having selectively variable dimensions for control of fluid flow therethrough.