Particular embodiments of the present invention include devices and methods for relieving excess pressure or vacuum pressure from a tank interior. An embodiment of a pressure relief device includes a housing having an opening associated with a first end, an opening associated with a second end, and an over-pressure opening. The device further including a pressure relief valve for selectively relieving pressure from a tank, the valve including an over-pressure opening seal biased by a first pressure bias means against a pressure valve seat associated with the over-pressure opening. The device also including a guide block translatable in an axial direction of a second bore of the housing and being biased toward the pressure valve seat by a second pressure bias means. The guide block is translatable independent of the over-pressure opening seal. The device also includes a vacuum relief valve for selectively relieving vacuum pressure in the tank.