A valve assembly in accordance with the present invention includes a head portion and a body portion. A throughbore extends through both the head portion and the body portion. A normal fluid flow path is formed within the valve assembly to provide for the controlled exit of a fluid. The valve assembly also includes an automatic pressure-relieving mechanism. The pressure-relieving mechanism includes a disc designed to burst or rupture at a predetermined pressure and an over-pressure fluid flow path for controlling the egress of over-pressure fluid.