Automatic High-efficient Welding Machine 1)Automatic root pass, fill, and cap pass 2)With two welding heads Automatic High-efficient Welding MachineSuitable for industries of: OIL ... , CNPC, SINOPEC, CNOOC, CNCEC, etc.Automatic small pipe welding station consists of welding manipulator, elbow welding machine, power source, self centering welding ...