This standard specifies the connection dimensions of welded or quick-change hose joints for hydraulic systems that use hydraulic oil (fluid) as the working medium.
GB/T 9065.3-1988 Hydraulic fluid power--Hose connector--Connecting dimension(Part 3:Welding or quick-action type) was changed to GB/T 9065.1-2015 Hydraulic hose fittings.Part 1:Hose fittings with O-ring face seal ends.