Roll Steering Revolving Coal Winning Craft
A Valve Type Puncture Needle
ball-and-dish seat type valve
valve gear
阀齿轮
气门机构
配气机构
阀动装置
阀动机构
气门机件
球阀
Box type power distribution substation
buttress type power house
central king pin type steering systme
channel type power station
明渠式水电站
明渠式水力电厂
引水式水电站
引水式水力电厂
conduit type power plant
die block type gear reduction unit
frequency cycle type power supply