2013GB/T 5657-2013 Technical specifications for centrifugal pumps (Class III)
1995GB/T 5657-1995 Technical specifications for centrifugal pumps--class Ⅲ
1985GB 5659-1985 Technical specification for multistage centrifugal pumps
GB 5659-1985 Technical specification for multistage centrifugal pumps was changed to GB/T 5657-1995 Technical specifications for centrifugal pumps--class Ⅲ.