Orifice adapters are used to restrict flow in a hydraulic system, usually to limit the speed of a hydraulically controlled movement.
Extreme caution should be used when replacing orifice adapters, to ensure the correct orifice is installed and that un-drilled parts are never supplied.
Please note, orifice adapters should be stocked in a completely separate location from standard adapters, since an orifice adapter installed in the place of a normal port size adapter will prevent normal operation of the hydraulic system.