Abstract: The specification describes a pressure release device for use with a manhole cover for releasing excess fluid pressure within a manhole or the like, the device comprising a tubular member having a tubular wall, a fluid inlet at one end thereof, a fluid outlet in the wall, an arrangement at the other end thereof for securing the member to the cover, and an arrangement for securing the member to the manhole adjacent a manhole opening for longitudinal movement of the member between a closed position whereat the cover closes the opening and an open position whereat the cover is removed from the opening permitting fluid flow from the manhole into the member via the inlet and outwardly of the member and the manhole opening via the outlet, the member securing permitting movement of the member from the closed position at a predetermined fluid pressure within the manhole and permitting the member to return to the closed position when the fluid pressure drops below the predetermined pressure.