Check valves are automatically actuated. They opened and sustained in the open position by the force of velocity pressure, and closed by the force of gravity. Seating load and resultant tightness is dependent upon back pressure.
This download include all size variations of the 159XU Check Valve by Crane Fluid Systems.
based on your comment below I am guessing you are having trouble loading in the size variations of this particular valve. Please refer to the user guide contained in the download file to explain the process of loading the component via the type catalogue. Hope this helps.
Nice but where'e the rest of it?