Before joint welding, project specifications require that the longitudinal weld of the pipe has a specific angular distance relative to the previous pipe. The Seam Aligner clamp allows for quick, precise, and safe positioning of the pipe, even with bent pipes that have angular inertia. The Seam Aligner is a clamp composed of 4 radio-controlled hydraulic arms equipped with 12 polyurethane-coated rollers that wrap around the pipe. The clamp is secured by safety lock valves on the hydraulic circuit. After closing the clamp around the pipe, the operator uses the remote control to rotate the pipe clockwise or counterclockwise until the longitudinal weld of the pipe reaches the desired position relative to the previous pipe section.