Directional Flow Controls apply orifice technology in one flow direction and free flow in the other. They work on the principal of Flow Restriction with the orifice diameter being identified in the part number. In addition to orifice diameter, Air Logic controls many smaller factors that have an impact on the total restriction of the orifice. A moving disk changes position based on the flow in the circuit. In the controlled direction, the orifice is the only path the media can flow through. In the opposite direction, the disk moves and the media is free to flow through the product unrestricted.