A valve is disclosed. The valve can be mounted through a wall, for example in the hull wall of a submersible vehicle. The internal components of the valve can be readily removed, serviced and/or replaced without removing the valve body from the wall. A filling assembly is also disclosed, which mates with the valve to deliver a fluid from one side of the wall, through the valve and into a storage tank or other apparatus disposed on the opposite side of the wall. The filling assembly actuates the valve to open a fluid pathway therethrough in order to deliver fluid to a storage tank or other apparatus connected to the valve's exit port.