1. Design manufacture: API 602
2. Connect the size of end:
1)Bear the socket size and press ANSI B16.11; JB/T1751
2)Thread end size according to ANSI B1.20.1; JB/T7306
3)Butt welding end size according to ANSI B16.25; JB/T12224
4)Flange end size according to ANSI B16.5; JB79
3. Valve inspection and experiment: API 598; GB/T13927: GB/T9092
4. Material according to ANSI/ASTM stipulation
5. Main body material: A105; LF2; F5; F11; F22; 304(L); 316(L); F347; F321; F51; MONEL; 20 alloy and so on.