This SAE Recommended Practice has been set up by Subcommittee 4 of the Off-Road MachineryTechnical Committee and is primarily for directional control valves on construction and industrial machineryequipment as referenced in SAE J1116. The purpose is to establish port area to flow relationship and match valve spool eye ends in relation to rated capacity.Port connections are optional for either the 4-bolt split flange connection or the internal straight thread "O" ring connection.