How should shell-and-tube titanium heat exchangers be installed and maintained?

Introduction

Shell-and-tube heat exchangers are widely used in chemical processing, seawater desalination, power generation, and industrial cooling systems. These systems face high pressures, corrosive fluids, and mechanical stresses. Selecting the correct titanium grade, plate thickness, and surface finish, along with proper installation and maintenance practices, is crucial for long-term efficiency and reliability.

GR2 Titanium Sheets are preferred for submerged and high-pressure sections due to their exceptional corrosion resistance, strength, and durability.

Natural internal linking: For thickness guidance, see Titanium Sheet Thickness Guide. For welding techniques, refer to Titanium Sheet Welding and Fabrication Techniques.

1. Material Selection for Shell-and-Tube Exchangers

Case Study 1 – Seawater Desalination Plant:
A desalination facility installed GR2 pickled tubes and tube sheets. After 10 years of continuous operation, the system showed no leaks, no pitting, and zero corrosion, outperforming stainless steel alternatives, which required maintenance every 3–5 years.

Case Study 2 – Chemical Process Heat Exchanger:
A chemical plant with aggressive brine solution used GR2 plates and tubes with 6 mm thickness. After 8 years, inspections confirmed the structural integrity and corrosion-free performance, reducing downtime and maintenance costs significantly.

2. Installation Guidelines

2.1 Pre-Installation Checks

• Inspect all titanium sheets and tubes for scratches or dents.
• Verify dimensions, thickness, and surface finishagainst design specifications.
• Confirm that welding and CTL equipmentcan handle specified thickness and grade.

2.2 Assembly Tips

• Tube-to-Sheet Alignment:Ensure uniform spacing to reduce thermal stress.
• Expansion Allowances:Allow for thermal expansion during operation to prevent deformation.
• Fastening:Use titanium bolts or compatible materials to prevent galvanic corrosion.

Example:
A GR2 exchanger used TIG welding with post-weld pickling for all tube-to-sheet joints. After 7 years, no leaks or corrosion were observed.

3. Maintenance Best Practices

3.1 Inspection

• Visual Inspection:Annually check welds, tubes, plates, and fasteners.
• Internal Inspection:Every 3–5 years, examine for scaling, biofouling, or micro-pitting.

3.2 Cleaning

• Avoid abrasive cleaning to protect titanium’s passivation layer.
• Use chemical descaling solutionscompatible with titanium to remove deposits.

3.3 Preventive Measures

• Replace gaskets and seals periodically.
• Monitor for mechanical stress pointsand vibration effects.
• Avoid contact with dissimilar metalsto prevent galvanic corrosion.

Case Study 3 – Offshore Platform:
An offshore facility conducted annual inspections and chemical cleaning of GR2 shell-and-tube heat exchangers. After 8 years, plates and tubes remained intact, demonstrating the long-term benefits of proper maintenance.

4. Engineering and Procurement Perspective

• Grade Selection:GR2 for immersion and high-pressure zones, GR1 for non-submerged areas.
• Thickness Determination:Balance mechanical load, pressure, and corrosion environment.
• Fabrication Requirements:Ensure suppliers can perform CTL, welding, forming, and post-weld pickling.
• Procurement Tip:Include grade, thickness, surface finish, and welding certification requirements in RFQs to reduce risk and ensure performance.

Practical Advice:
Coordinate with engineering teams to match material properties and fabrication capabilities with design specifications. This minimizes installation errors and increases the heat exchanger’s service life.

5. FAQ – Detailed

Q1: What thickness is recommended for seawater tubes?
A: 2–5 mm depending on operating pressure, flow rate, and corrosion environment.

Q2: Can BA plates be used in tube sheets?
A: Only in low-corrosion zones; pickled plates are preferred for seawater or aggressive chemical contact.

Q3: How often should post-weld pickling be applied?
A: After every welding operation to restore the passivation layer in the heat-affected zone.

Q4: Is TIG welding suitable for all Titanium Plates?
A: TIG is ideal for thin-to-medium plates; plasma welding is recommended for thick plates.

Q5: How to prevent galvanic corrosion?
A: Use titanium fasteners or compatible metals and avoid contact with dissimilar metals in wet zones.

Q6: How to extend the service life of heat exchangers?
A: Proper material selection, correct thickness, precise welding, post-weld pickling, and regular maintenance inspections are key.

6. Conclusion

Proper installation and maintenance of shell-and-tube titanium heat exchangers ensure maximum corrosion resistance, thermal efficiency, and operational safety.

At ProX Metal, we provide high-quality GR2 and Gr1 Titanium sheets, support CTL processing, welding, forming, and post-weld pickling, and offer engineering expertise to optimize heat exchanger design, reduce maintenance, and achieve long-term, reliable performance.