Abstract: The present invention provides a pressure-release sealing cap for a reservoir including a rotatable platform with a ramp connected to a rotatable enclosure. A movable plunger with connected to a movable pressure-release member with a guide stud and a valve means. The guide stud disposed on said ramp between said first and second reference portions, while said sealing cap is installed on said reservoir and the guide stud disposed to rotate on the ramp on rotation of the enclosure to lift the valve means, to release the excess pressure while concurrently removing the sealing cap from the reservoir. The pressure-releasing member is actuated indirectly to release excess pressure from the reservoir, in a controlled and gradual manner.