This standard specifies the structural length and tolerances of valves with internal thread connections. This standard applies to internal thread connection gate valves, globe valves, throttle valves, ball valves, plug valves, diaphragm valves and check valves.
GB/T 15188.3-1994 history
2005GB/T 12221-2005 Metal valves-Face to face,end to end,center to face and center to end dimensions
1994GB/T 15188.3-1994 Face-to-face,centre-to-face,end-to-end and centre-to-end dimensions of valves-Female screw valves
GB/T 15188.3-1994 Face-to-face,centre-to-face,end-to-end and centre-to-end dimensions of valves-Female 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.