Dispenser cap for pressurised fluids

A valve actuator for a container containing a pressurised fluid and having an operable valve via which the fluid is dispensed, the actuator comprising:

• a mounting attachable to the container,
• a control part moveably mounted on the mounting, the control part incorporating a valve operator operably connectable to the valve when the mounting is attached to the container, and incorporating an outlet conduit via which fluid may flow from the valve to an outlet opening, the control part being moveable in a first direction to operate the valve to release fluid from the container, and being moveable in a second direction after use to thereby operate the valve to cease the flow of fluid;
• comprising:
• a variable volume post-expansion chamber provided in communication with the outlet conduit via an expansion opening between the outlet conduit and the post-expansion chamber and in which residual fluid remaining in the outlet conduit after use can expand,
• a variable volume suction chamber in communication with the outlet conduit via a suction opening between the outlet conduit and the suction chamber and adjacent to the expansion opening,
• the volume of the variable volume post expansion chamber and the suction chamber being reduced on movement of the control part in the first direction and increased on movement of the control part in the second direction, such that the increase in volume of the suction chamber results in negative pressure within outlet conduit which draws fluid in the outlet conduit back away from the outlet opening,
• the suction opening being more constricted relative to the flow of the fluid than is the expansion opening such that fluid drawn back from the outlet opening expands into the expansion chamber in preference to passing through the suction opening.