启、阀件密封面    Blowdown Sealing Face

泄料（放空，排污）阀    Blowdown valves

制动阀    Brake valves

对夹    Butt Clamp

蝶式缓冲止回阀    Butterfly Type Non-slam Check

蜗轮传动蝶阀    Butterfly Valves with Gear Actuator

对焊连接阀    Buttwelding valves