... rig 3,CE,ISO9001 4,Warranty 2Ys 2012 New type DTH drilling rig:Zhengzhou Dayu Machinery Co ... DTH drilling rig1,Safe and stable traveling system of Dayu DTH drilling rigLow gravity, great ground clearance ... small vibration and working stable. 3,New type boom of Dayu DTH drilling rigThe scope adjustable sysytem ... and reduce the sticking rate.Technical data of Dayu DTH drilling rigModel DY140 DY130 DY120 ...