A valve assembly for use with an unmanned aerial vehicle is provided and includes an inlet tube, a shuttle, a base plate, a screw assembly, and a spacer block. The shuttle is partially disposed within the inlet tube and is configured to be placed in a first position where the shuttle abuts the inlet tube and a second position where the outer surface is disposed in spaced relation to the inlet tube. The base plate extends between a first end portion that defines a cavity therein and a second end portion. The screw assembly is disposed within the cavity of the base plate and is coupled to a portion of the shuttle. The spacer block is interposed between the second end portion of the inlet tube and the first end portion of the base plate and is configured to maintain the inlet tube and the base plate in spaced relation.