a few casing and more circulating
air casing
空气隔层
空气夹层
烟囱外套筒
空气套
气隔套
通风道
[空]气夹层
气套
气夹层
all casing and rotation drill
All Casing Foundation Drilling Equipment
all casing grab drilling
all casing rotary drilling
API standard casing head
Asbestos-cement pipe for well casing
barrel casing feed pump