A chip bin for wood chips in a continuous digester system includes internal steaming that is controlled in response to both the interior temperature across the level of chips in the bin, and the level of chips in the bin, so as to substantially prevent cool, non-condensible gas-laden chips from accumulating at the top of the chip column in the bin, and to substantially prevent steam blow-through. The temperature probe used in the chip bin has a temperature sensing portion with a length of about ten to twenty feet instead of the conventional five foot length, and extends across the level of the chips to a position about five feet below the level of chips. Control of steam added to the bin is provided utilizing a controller which controls the position of one or more valves in one or more steam conduits, each valve having multiple open positions and a closed position. A vacuum and pressure relief device is disposed in a non-condensible gases vent from the bin which minimizes the potential for gross gas flow variations across it. The relief device includes a solid interior peripheral portion of the vent, a gate mounted for pivotal movement by a pivot shaft, and a casing which is a cylindrical sector (having a sector angle of about 30.degree.-60.degree.) in which the gate pivots. The casing is mounted in the solid interior peripheral portion and a brush seal is provided between the gate and the cylindrical sector casing.