2012 New type DTH drilling rig 1,Driving type:pneumatic and ... Crawler DTH drilling rig 3,CE,ISO9001 4,Warranty 2Ys 2012 New type DTH drilling rig:Zhengzhou Dayu Machinery Co.,Ltd. have ... rig6,Diesel movable screw air compressor for DTH drilling rig7,Electric movable screw air compressor for DTH drilling rig1,Safe ... of DTH drilling rigZhengzhou Dayu Machinery Co.,Ltd web: 2012 New type DTH drilling rig