A valve for selectively fluidly communicating a first fluid volume and a second fluid volume includes a valve body, an inlet orifice in fluid communication with the first fluid volume, and an outlet aperture in fluid communication with the second fluid volume. The valve also includes an activation member axially movable relative to the valve body. The valve is operable in a first mode in which the valve opens in response to manual actuation of the activation member. The valve is operable in a second mode in which the valve opens when a pressure difference between the first and second fluid volumes reaches a predetermined value, and the valve closes when the pressure difference between the first and second fluid volumes is less than the predetermined value.