An apparatus for delivering fluid from a fluid container comprises a housing to which a fluid container is attachable, a slider movably disposed in the housing and a resilient having a first end connected to the housing and a second end connected to the slider. Upon receiving an external force, the slider moves relative to the housing from a first position toward a second position to deform the resilient member from an original state to a deformed state, and upon release of the external force, the resilient member is allowed to resume to the original state to move the slider toward the first position to urge the slider against the fluid container to deliver fluid from the fluid container under a constant fluid flow rate.
