... Pipe & Flange Welding Machine 1) Two models available: 16" and 16"-36" type 2)CO2 / MIG / SAW are optional Automatic Two-Torch Pipe ... Rotary Engineering, Petrol Steel, CNPC, SINOPEC, CNOOC, CNCEC, etc.The machine is able to synchronously weld on inside & outside of flanges ... effectively control welding speed.Features:1, Two models available: 16" type and 16"-36" type2, CO2 / MIG / SAW are optional3, ...