蝶阀+止回阀式进气阀
butterfly valve + non-return intake valve
差压式截止止回阀
differential stop check valve
蝶式缓冲止回阀
Butterfly Type Non-slam Check
立式止回阀
vertical lift check valves
内螺纹升降式止回阀
inside screw lift check valve
扫描式冲击回波法
scanning type shock echo method
双板对夹式止回阀
dual plate wafer type check valve