Carbon Steel Spiral Heat Exchange Coil for Boiler, manufactured from 20G / A106‑B seamless boiler tube. Helical spiral winding structure creates fluid turbulence for high heat transfer efficiency. Compact size, reliable high‑pressure & high‑temperature performance. Full customization on tube size, coil diameter, pitch, heat duty. Available for boiler steam generator, waste heat recovery and tank immersed heating service. Hydro‑test & NDT inspection provided, material certificate supplied.