3API 600-1981. Steel gate valves flanged and butt-wedge ends.Eight Edition,[S].
4董祖珏.焊接手册第二版[M].北京:机械工业出版社,2001..
5BS 1414-1975 (R1998 R1990), Specification for steel wedge gate valves (flanged and butt-welding ends) for the petroleum .petrochemical and alliedindustries [S].
6BS 1873-1975 (R1990), Specification for steel globe and globe stop and check valve (flanged and butt-welding ends) for the petroleum . petrochemical and alliedindustries [S].
7BS 1868-1975 (R1990), Specification for steel check valve(flanged and butt-welding ends) for the petroleum . petrochemical and allied industries[S] .
