LYCES Global: Automated Heat Exchanger U-Tube Bending & Hydrotest Line Case Study for Sandvik India

The project site at Sandvik’s manufacturing facility in India.

 
 
 
Project Dimension / Indicator
 
Technical Specifications & Delivery Standards
 
 
 
 
 
Project Year
 
2011
 
 
 
Applicable Standards
 
 • ASME SA688 / SA557
 • ASTM A688 
 
 
 
Hydrostatic Testing
 
100% Full-Pressure Paperless Data Traceability
 
 
 
Control System
 
Siemens Industrial PLC Full Closed-Loop Control
 
 
 
Surface Anti-Corrosion
 
Sa2.5 Shot Blasting + RAL 5005 Signal Blue Thermosetting Coating
 
 
 

I. Project Background & Industry Challenges

Back in 2011, Sandvik India initiated a procurement plan for an automated heat exchanger tube processing line to meet the technical demands of nuclear power and high-pressure heat exchangers in European and global markets.

In processing austenitic stainless steel heat exchanger tubes under ASME SA688 / SA557 standards, the project faced several key engineering challenges:

1. Large-Angle Bending Tolerances: Bending long U-tubes at large angles easily leads to excessive wall thinning and out-of-roundness (ovalization).
2. Hydrostatic Test Data Traceability: Nuclear and high-pressure applications require 100% high-pressure hydrostatic testing for every tube, along with archived digital records.
3. Residual Stress Relief: Stress relief annealing in the bend zone requires precise thermal control of the heat-affected zone while preventing surface oxidation on the tubes.

An operator running the CNC bending system for long U-tubes.

II. Tailored "4-in-1" Automated Turnkey Solution (2011)

To meet the production requirements of Sandvik's plant in India, Hoilda (LYCES) developed and delivered a complete closed-loop automated U-tube processing and testing line in 2011:

CNC 360° Long U-Tube Bending / Push-Bending System

• Technical Features: Driven by hydraulics with PLC closed-loop control, featuring 360° continuous bending capabilities. Equipped with a smart auxiliary push mechanism that automatically engages when the bend angle exceeds 90°, keeping wall thinning and ovality strictly within ASME SA688 standard tolerances.

Fully Automated U-Tube High-Pressure Hydrostatic Testing System

• Technical Features: Configured with dual-head (A/B) clamping seals, automatically executing water filling, air venting, secondary boosting, pressure holding, and pressure release. Integrated with paperless recorders to log real-time pressure-time curves, providing verifiable inspection certificates for shipped tubes.

Process Tube Cutting & End Facing / Chamfering Integrated Machine

• Technical Features: Dual-cylinder synchronized clamping with adjustable feed speed (0-375mm/min) and cutting torque. Completes excess process tube cutting and flat-end chamfering in a single setup, ensuring smooth, burr-free end faces.

Localized Stress Relief Annealing Furnace

• Technical Features: Features a fiberglass thermal insulation structure, combined with protective gas purging (anti-oxidation) and fan cooling. Paperless recorders precisely track temperature control curves, effectively restoring intergranular corrosion resistance in the bend area.

III. Compliance, Controls & Coating Standards

• Siemens Control System: The entire line is equipped with Siemens industrial PLCs and touchscreens, featuring safety interlocks and fault diagnostics.
• RAL 5005 Signal Blue Anti-Corrosion Coating: Pre-factory treatment includes Sa2.5 shot blasting, followed by RAL 5005 (Signal Blue) thermosetting anti-corrosion coating to withstand cross-border transport and tropical environments.
• Paperless Electronic Data Traceability: Test pressure and annealing temperature data are digitally archived to satisfy international audit requirements.

The gantry system smoothly transferring ultra-long heat exchanger tubes across the line.

IV. Project Significance & Technical Legacy

Successfully delivered and commissioned in 2011, this project achieved turnkey automation from tube bending and high-pressure testing to heat treatment, fully meeting ASME SA688/SA557 standards.

As a flagship project that entered Sandvik's global supply chain 15 years ago, this case demonstrates Hoilda's engineering expertise in tube processing and laid a solid foundation for subsequent technical iterations and automated equipment R&D.

V. Frequently Asked Questions (FAQ)

Q1: How does the Hoilda tube bender control the wall thinning rate during large-angle bending of long U-tubes?

A: The system is equipped with an Auxiliary Push mechanism. When the bend angle exceeds 90°, the push device activates synchronously to reduce tensile stress, maintaining wall thinning and ovality within ASME SA688 allowable tolerances.

Q2: How do the hydrostatic testing and annealing data fulfill ASME audit requirements?

A: Both the hydrostatic tester and annealing furnace integrate paperless recorders that automatically log pressure-time and temperature-time curves, supporting digital data export and full-lifecycle record traceability.

VI. Contact Us & Technical Support

If you are planning an automated turnkey solution for heat exchanger tubes or pipe processing, feel free to contact the Hoilda engineering team to discuss customized equipment selection and planning.

• Email📧: [[email protected]]
• Website🌐: [www.lyccnc.com]

Processed and inspected U-tubes neatly stacked in dedicated storage racks.