When sourcing boiler welding machines, you must prioritize automated orbital welding capabilities and high-precision pulse control. Key specs include IGBT inverter technology for stable arcs, a duty cycle of at least 60-100% for continuous industrial use, and programmable logic controllers (PLC) to store welding parameters for different pipe diameters. Ensure the machine supports TIG (Tungsten Inert Gas) or Submerged Arc Welding (SAW) processes, as these are standard for high-pressure vessel integrity.