FOSHAN, China – Guangdong WEIYI Intelligent Welding Equipment Co., Ltd. has announced a comprehensive upgrade to its industrial stainless steel tube mill series, targeting demanding applications in petrochemical, food processing, dairy, pharmaceutical, and sanitary piping systems. Unlike decorative mills that prioritize surface aesthetics, industrial tube mills must deliver superior weld integrity, precise dimensional tolerances, and full compliance with international standards such as ASTM A249 (welded boiler and superheater tubes), ASTM A270 (sanitary tubing), and ASTM A312 (seamless and welded austenitic stainless steel pipe). WEIYI’s new industrial mill series has been redesigned from the ground up to meet these stringent requirements while maximizing production efficiency and minimizing material waste.
The industrial stainless steel tube mill handles outer diameters from 12 mm to 219 mm and wall thicknesses from 0.5 mm to 4.0 mm, supporting grades including 304L, 316L, 321, and duplex stainless steels. Core technical innovations include a multi-roller constant-wall forming system that reduces longitudinal stress and ovality, a plasma or TIG welding station with seam tracking and automatic gap control, and an optional internal seam bead rolling device that flattens the weld bead without compromising corrosion resistance. The internal bead rolling device is particularly critical for sanitary and dairy applications, where any internal protrusion can trap product residue and promote bacterial growth. WEIYI’s version uses hydraulic pressure control to achieve a smooth internal surface with bead height reduced to less than 0.1 mm.
Another major upgrade is the integration of an inline bright annealing machine, which uses a controlled hydrogen or nitrogen atmosphere to recrystallize the weld zone and heat-affected zone. This process restores corrosion resistance and ductility to levels equivalent to the base metal, a requirement for ASTM A249 and A270 compliance. For customers who do not require a bright finish, WEIYI also offers a conventional black annealing machine as a lower-cost alternative. Both annealing options can be configured for either inline or offline operation depending on line speed and floor space availability. WEIYI’s R&D team reports that the new industrial mill achieves a weld tensile strength exceeding 95% of the base metal and an elongation rate above 40% in post-weld tests.
WEIYI has already delivered two complete industrial tube mill lines to a petrochemical fittings manufacturer in Thailand and a sanitary tube producer in India. The Thai customer reported successful production of ASTM A312 TP316L pipe for chemical transfer lines, passing hydrostatic testing and eddy current inspection with a rejection rate below 1.5%. Meanwhile, the Indian customer produced ASTM A270 tubing for a dairy processing plant, achieving an internal surface roughness of less than 0.4 Ra. “Industrial stainless steel tube production leaves no room for compromise on weld integrity or dimensional consistency,” said the director of WEIYI’s pipe mill division. “Our latest industrial mill series gives customers the confidence to bid on critical infrastructure and hygiene-sensitive projects, knowing that every meter of tube meets the toughest global standards.” WEIYI is also offering a complete set of new rolls customized to each customer’s profile portfolio, along with regrinding and reconditioning services to extend roll life and reduce long-term operational costs. Turn-key project services include factory layout design, installation supervision, and operator training, ensuring a smooth ramp-up to full production capacity.