U-Tube Bender & Hydrostatic Tester Production Line

Lyces has partnered with Sandvik (now Alleima) since 2008, delivering high-performance automated tube processing lines.

Ⅰ. Project Background: Decades of Trust from a Global Material Leader

Sandvik—a world-class manufacturer of advanced stainless steels and special alloys—maintains uncompromisingly high standards for manufacturing precision, automation safety, and cross-border equipment delivery.
Between 2008 and 2010, we established a robust, long-term international partnership with Sandvik. To satisfy their precise dimensional tolerances and surface corrosion protection requirements for premium heat exchanger U-tubes, we custom-developed and delivered a high-performance, closed-loop U-bent tube processing turnkey production line. This automated solution was successfully commissioned at Sandvik's facility in China and subsequently exported and delivered to Sandvik India.
Fully compliant with ASME SA688 and ASME SA556 international standards, these production lines have been operating stably for nearly 20 years. This enduring performance stands as a monumental proof of our machinery's industrial-grade durability and our engineering capability to support global industrial supply chains.

Ⅱ. Technical Core: Rigorous 4-in-1 Turnkey Workflow & Structural Compliance

To eliminate tube end deformation and satisfy international condenser and feedwater heater manufacturing codes, our production line follows an ultra-rigorous, ASME-compliant sequence to guarantee that every tube end is flawless:

  [1. 360° CNC Bending]  →  [2. 100% Hydro-Testing]  →  [3. Clamping Margin Cutting & Chamfering]  →  [4. Stress-Relieving Annealing]

1. Long U-Tube Bending Machine (Capable of 270° Bending via 360° Rotary Head)

Our customized CNC long U-tube bender is engineered to process extra-long heat exchanger tubes, overcoming critical industry bottlenecks:

360° Continuous Bending Capability: Unlike standard 180° benders, our machine is designed with a specialized rotary head and tooling set that allows for seamless 360-degree continuous bending. This provides supreme flexibility for complex coil configurations and tight-radius space constraints.
ASME SA556 & SA688 Dimensions: The bending process strictly controls wall thinning rates, ovality (out-of-roundness), and surface scratches, fully satisfying ASME SA556/SA556M and ASME SA688/SA688M specifications for high-end heat exchanger tubes.

2. Automated U-Tube Hydrostatic Testing Machine (Pre-Processing Inspection)

Before any final trimming or edge bevelling occurs, the fully bent U-tubes undergo a 100% online hydrostatic pressure check to establish an absolute safety barrier:

100% Pressure & Leak Testing: The machine automates water filling, high-pressure holding, and sealing detection, ensuring that every single heat exchanger tube achieves zero leaks and zero defects under maximum operating pressures.

3. Clamping Margin Cutting & Dual-End Precision Chamfering Machine

Once hydrostatic testing is complete, the tubes enter the end-finishing stage to ensure perfect joint preparation:

Why Do We Cut After Hydrostatic Testing? Cold bending and high-pressure testing require clamping margins (blind areas) at both ends of the tube. This integrated station precisely slices off the non-conforming clamping margins, completely preventing any secondary inner diameter distortion or tube mouth deformation caused by pressure testing clamping.
Simultaneous Dual-End Chamfering: Right after cutting, the machine chamfers both tube ends simultaneously. This guarantees highly consistent bevel angles and smooth tube faces, ensuring seamless fit-up and high-purity welding during final assembly.

4. Localized Stress-Relieving Annealing Furnace (With Glass Fiber Insulation)

To restore the mechanical properties of the bend area after cold working and prevent Stress Corrosion Cracking (SCC), the line integrates localized heat treatment equipment:

Innovative Glass Fiber Insulation: Back in 2008, our engineering team pioneeringly integrated high-density glass fiber insulation materials into the heating furnace chamber. This robust insulation design dramatically minimized heat dissipation, secured exceptional temperature uniformity, cut energy loss, and fully protected surrounding automated components.
Post-Bend Heat Treatment (PBHT): Precisely controls the heating and cooling curves to completely relieve residual stress in the U-bend portion, meeting absolute ASME heat-treatment specifications.

Ⅲ. Technical Specifications & ASME Compliance Matrix

   Process Module / Dimension  Core Technical Specifications & Engineering Capability  Compliance & Supply Chain Standards  
 
   1. CNC Long U-Tube Bending   • Up to 360° continuous seamless bending
 • Strict control over wall thinning, ovality, and surface defects   • ASME SA688 / SA688M
 • ASME SA556 / SA556M  
  2. Automated Hydrostatic Testing   • 100% online whole-tube pressure holding test
 • Automated water filling and high-pressure ceiling for zero leakage   • Meets severe heat exchanger hydro-test safety inspection codes  
  3. Clamping Margin Sizing & Chamfering   • Post-testing precision cutoff of non-conforming blind areas
 • Simultaneous dual-end chamfering with zero secondary ID distortion   • Perfect bevel alignment for automatic industrial orbital welding  
  4. Post-Bend Heat Treatment (PBHT)   • Custom-engineered High-Density Glass Fiber Insulation Furnace
 • Precision thermal curves to eliminate Stress Corrosion Cracking (SCC)   • Fully satisfies mandatory ASME PBHT heat treatment protocols  
  5. Automation & Surface Coating   • Full line integration with Siemens PLC & HMI Architecture
 • Shot blasting + Primer + RAL 5015 Sandvikblue Paint (DFT > 100 microns)   • Siemens global industrial tracking standards
 • Strict Sandvik Painting Requirements  
  6. Field-Proven Lifespan   • Active service pool for nearly 20 years (Since 2008-2010 commissioned)   • Multi-plant field validation (Sandvik China & Sandvik India)

Process Module / Dimension	Core Technical Specifications & Engineering Capability	Compliance & Supply Chain Standards
1. CNC Long U-Tube Bending	• Up to 360° continuous seamless bending • Strict control over wall thinning, ovality, and surface defects	• ASME SA688 / SA688M • ASME SA556 / SA556M
2. Automated Hydrostatic Testing	• 100% online whole-tube pressure holding test • Automated water filling and high-pressure ceiling for zero leakage	• Meets severe heat exchanger hydro-test safety inspection codes
3. Clamping Margin Sizing & Chamfering	• Post-testing precision cutoff of non-conforming blind areas • Simultaneous dual-end chamfering with zero secondary ID distortion	• Perfect bevel alignment for automatic industrial orbital welding
4. Post-Bend Heat Treatment (PBHT)	• Custom-engineered High-Density Glass Fiber Insulation Furnace • Precision thermal curves to eliminate Stress Corrosion Cracking (SCC)	• Fully satisfies mandatory ASME PBHT heat treatment protocols
5. Automation & Surface Coating	• Full line integration with Siemens PLC & HMI Architecture • Shot blasting + Primer + RAL 5015 Sandvikblue Paint (DFT > 100 microns)	• Siemens global industrial tracking standards • Strict Sandvik Painting Requirements
6. Field-Proven Lifespan	• Active service pool for nearly 20 years (Since 2008-2010 commissioned)	• Multi-plant field validation (Sandvik China & Sandvik India)

Ⅳ. International Supply Chain Standards & Asset Protection

To ensure seamless integration into international tier-1 corporate asset pools, our equipment complies with rigid global manufacturing, automation, and anti-corrosion coating specifications:

Siemens Control Infrastructure: The entire automated production line is programmed and driven by a Siemens Control Architecture with an interactive HMI touch-screen interface. It delivers flawless manual troubleshooting modes, real-time input/output diagnostic signals, and easy ingredient recipe saves for multi-specification tube processing.
Sandvik Painting Requirements Standard: All heavy-duty welded structural elements undergo mandatory shot blasting and receive a protective industrial primer coat within 6 hours of cleaning to prevent flash rust. The finishing coat is applied via professional spray systems to match RAL 5015 (Signalblau / Sandvikblue) anti-corrosion aesthetics. The total dry film thickness (DFT) of the two layers of paint is strictly verified to exceed 100 microns, ensuring supreme weatherability in harsh chemical plant environments.

💡 Next Series Preview: As Sandvik’s trusted long-term tube automation partner since 2008, this high-precision ASME SA688 turnkey production line was just the beginning of our deep cooperation. In our Next successful Implementation, we will uncover the historical records from 2011 to 2024, detailing Sandvik's subsequent machinery orders, advanced technology re-fits, customized mold expansions, and long-term lifecycle technical support. Stay tuned.

Lyces&Sandvik(Alleima) Commissioning