This standard specifies the structural length and limit deviation of valves connected by external threads. This standard applies to globe valves, throttle valves, lift check valves and ball valves with external thread connections.
GB/T 15188.4-1994 history
2005GB/T 12221-2005 Metal valves-Face to face,end to end,center to face and center to end dimensions
1994GB/T 15188.4-1994 Face-to-face,centre-to-face,end-to-end and centre-to-end dimensions of valves-Male screw valves
GB/T 15188.4-1994 Face-to-face,centre-to-face,end-to-end and centre-to-end dimensions of valves-Male screw valves was changed to GB/T 12221-2005 Metal valves-Face to face,end to end,center to face and center to end dimensions.