An apparatus and method to improve delivery of liquid anhydrous ammonia from aportable liquid NH3 tank in cold temperatures includes an air compressorcoupled to thevapor port of a portable liquid NH3 tank used to supply liquid anhydrousammonia to ananhydrous ammonia fertilizer applicator. The apparatus can include an actuatorto relievethe tank of compressed air after the tank is empty of liquid anhydrousammonia.