FAQ

• What is the FXT20 Pro-U U-shaped orbital welding machine?

  The FXT20 Pro-U is a specialized automated system designed for the high-precision socket welding of heat exchanger U-tubes to straight tubes. Known as a "precision surgeon" for tube bundles, it utilizes pulse TIG welding technology to complete 360° circumferential fillet welds. It is specifically engineered to ensure leak-free operation in high-temperature and high-pressure environments, replacing inconsistent manual welding.

• What pain points does the FXT20 Pro-U solve in heat exchanger manufacturing?

  It addresses four critical industry challenges: burn-through of thin-walled tubes, inconsistent penetration in confined spaces, oxidation of the internal weld bead, and the cracking of welds during post-weld tube expansion. By using digital 8-zone programming, it ensures a uniform weld formation that manual welding cannot replicate.

• Can the FXT20 Pro-U weld ultra-thin-walled tubes without burn-through?

  Yes. The FXT20 Pro-U features ultra-low current control with arc initiation starting at just 5A. This precision, combined with a Pulse DC TIG control system, allows it to weld tubes with a combined wall thickness of ≤1.6mm perfectly, making it ideal for small-diameter heat exchanger tubes (φ16mm and below).

• What materials are compatible with the FXT20 Pro-U U-tube welder?

  The system is optimized for austenitic stainless steel (304, 316L) and duplex stainless steel (2205). Its integrated internal argon gas channel prevents sensitization and oxidation, maintaining the original physical and corrosion-resistant properties of the stainless steel.

• Why is internal argon protection critical for U-tube welding?

  During the welding of stainless steel, high temperatures can cause the internal wall to oxidize and turn black. The FXT20 Pro-U integrates an internal argon interface that delivers protective gas inside the tube simultaneously with the external torch. This ensures a silver-white metallurgical appearance on the inner wall, meeting GMP cleanliness standards without the need for pickling.

• Is the FXT20 Pro-U compatible with the "Weld Before Expand" process?

  Absolutely. The FXT20 Pro-U is designed specifically for the "weld before expand" sequence required by standards like ASME VIII and GB/T 151. By precisely controlling heat input, it creates high-strength welds that do not crack during the subsequent tube expansion process, eliminating crevice corrosion risks.

• How much space is required between tubes for the FXT20 Pro-U welding head?

  The welding head features a compact horseshoe-shaped structure that requires a minimum tube center spacing of 38.1mm. This allows it to access and weld compact tube bundles where manual welding is impossible due to dense tube arrangements.

• Is the FXT20 Pro-U portable for on-site heat exchanger installation?

  Yes. The welding head is extremely lightweight at only 3kg, and the power source weighs 22kg. It is designed for portability, allowing operators to move between workstations or perform on-site repairs easily with its standard 8-meter flexible cable.

• How does the FXT20 Pro-U ensure consistency across 360° of welding?

  It uses an 8-zone independent programming system and a full closed-loop servo control system. This allows the machine to automatically adjust current and rotation speed at different positions (such as 6 o'clock vs. 12 o'clock) to compensate for gravity effects, ensuring uniform weld beads throughout the entire circumference.

• What technical support does Feiyide (FYID) offer for overseas customers?

  We provide 7×18 hours online video support in English and Chinese, a 12-month warranty, and lifetime technical assistance. Our service includes remote diagnosis and PQR (Procedure Qualification Record) support to help customers optimize their welding parameters for specific materials and wall thicknesses.