Q series Wire-line Double Tube Barrel Core barrelCore Barrels include single tube type,Website:http://www.yikuangdrilling.com, double tube type and triple tube ... type. BMLC, NMLC, HMLC triple tube core barrels are generally ... BWT, NWT, HWT(Single Tube, Double Tube) WG series: EWG, AWG, BWG, NWG, HWG(Single Tube, Double Tube) WM series: EWM, AWM, ...