摘要 |
A method and apparatus is disclosed for controlling the flow of fluid in oil and/or gas production, involving a control device or an autonomous valve (2) operating by the Bernoulli principle and comprising a moveable disk or body (9) provided within a housing (4) for opening and closing said valve (2), involving use of a material (24) within the valve (2) that changes its properties as to shape and/or volume and/or elastic modulus when exposed to a chemical substance contained in the flow of fluid and thus altering said flow of fluid. |