Knife gate valve main standard (1) GB12232-89 "universal valve flanged iron gate valve" (2) GB12234-89 "universal valve flange and butt welding connection steel gate valve" (3) GB8486-87 "internal thread (4) GB8465.1-87 "internal thread connection gate valve, globe valve, ball valve, check valve basic size iron gate valve" (5) JB / T53162-94 "gate valve product quality Grading "(6) JB / T5298-91" Pipeline steel plate gate valve "(7) JB / Z243-85" Gate valve static pressure life test procedures "(8) JB / TQ648-88" Gate valve "(9) JB / T53200-94" iron price plate gate valve product quality classification "(10) JB / T53242-94" steel plate gate valve product quality classification "