| 摘要 |
An insert (10) for inclusion in a pressurised fluid container, for releasing a substance into the fluid from the insert when the pressure in the container is reduced, comprising a chamber (27) for storing the substance and from which the substance is released in response to said reduction in pressure in the chamber, wherein the chamber is provided with a valve means (28) which is closed to prevent communication between the interior of the insert and the exterior thereof when external pressure acting on the insert is below a predetermined pressure and which is opened to permit said communication when the external pressure acting on the chamber increases to a pressure which is not below said predetermined pressure. |
