What makes titanium sheets ideal for chemical reactor applications?
Chemical reactors operate in some of the most aggressive environments in industrial processing. They expose metallic materials to strong acids and bases, as well as high temperatures and pressures. To ensure the reactor's reliable, long-lasting performance, it is crucial to select the right grade, thickness and surface finish of Titanium Sheet.
Titanium GR1 and GR2 sheets are preferred in these environments for their excellent corrosion resistance, high strength-to-weight ratio, and thermal stability. Correct selection, fabrication, and post-weld treatment significantly influence equipment lifespan and maintenance costs.
For additional guidance on material selection and thickness, see GR1 vs GR2 Titanium Sheet – Detailed Comparison and Titanium Sheet Thickness Guide.
Material Selection and Reactor Applications
Titanium’s corrosion resistance is largely due to its self-passivating oxide layer. However, performance varies depending on media, temperature, pressure, and sheet treatment.
| Parameter | Recommendation | Notes |
| Sheet Grade | GR2 for highly corrosive media | GR1 suitable for mild chemicals |
| Thickness | 3–12 mm | Determined by reactor size and operating pressure |
| Surface Finish | Pickled preferred for aggressive media | BA acceptable for mild chemicals |
| Welding Method | TIG or Plasma | Proper shielding gas is essential |
| Post-Weld Treatment | Pickling required for pickled sheets | Restores passivation layer |
Example:
A GR2 pickled titanium reactor for sulfuric acid processing with 6 mm sheets and TIG welds showed no pitting or corrosion after 7 years, whereas previous stainless steel reactors required maintenance every 2–3 years.
Case Studies by Reactor Type
1.1 Small Organic Synthesis Reactor (0.5–2 m³)
- Chemical Environment:1–2 M hydrochloric acid, 60°C
- Material Choice:GR1 BA sheet, 3 mm
- Fabrication:TIG welding, no post-weld pickling
- Result:Panels maintained visual brightness and corrosion-free operation for 6 years
- Lesson Learned:BA sheets suffice for mild acids and allow easy inspection
1.2 Medium-Sized Sulfuric Acid Reactor (2–5 m³)
- Chemical Environment:Concentrated H2SO4, 80°C
- Material Choice:GR2 pickled, 5 mm
- Fabrication:TIG welding with post-weld pickling
- Result:Reactor corrosion-free for 10 years, reducing downtime
- Lesson Learned:Proper surface finish and post-weld pickling extend service life in aggressive media
1.3 Large Chlorinated Solvent Reactor (>5 m³)
- Chemical Environment:Chlorinated solvents, 90°C, 2.5 bar pressure
- Material Choice:GR2 pickled, 8 mm
- Fabrication:TIG welding, post-weld pickling, mechanical leveling
- Result:Zero micro-pitting after 12 years
- Lesson Learned:Thickness, surface finish, and post-weld treatment are critical for large-scale reactors
1.4 High-Temperature Nitric Acid Reactor (3–5 m³)
- Chemical Environment:Nitric acid, 95°C
- Material Choice:GR2 pickled, 6 mm
- Fabrication:Plasma welding, pickled after weld
- Result:No pitting or discoloration over 8 years
- Lesson Learned:For high-temperature operation, pickled GR2 sheets resist acid attack better than BA sheets
Thickness and Pressure Considerations
| Reactor Size | Operating Pressure (bar) | Recommended Thickness (mm) | Sheet Grade | Surface Finish |
| Small (<2 m³) | 0.5–1 | 3 | GR2 | Pickled |
| Medium (2–5 m³) | 1–2 | 5 | GR2 | Pickled |
| Large (>5 m³) | 2–5 | 8–10 | GR2 | Pickled |
Engineering Note: Thicker sheets improve mechanical strength and corrosion resistance, especially under pressure fluctuations and high-temperature conditions.
Surface Finish Impact
| Feature | Bright Annealed (BA) | Pickled |
| Appearance | Shiny, reflective | Matte, uniform |
| Corrosion Resistance | Moderate | Excellent in aggressive media |
| Maintenance | Easy visual inspection | Requires chemical cleaning |
| Weld Heat Tint | Minor | Must be removed post-weld |
| Recommended Application | Mild acids, instrumentation | Strong acids, bases, high-temperature reactors |
Case Example:
In hydrochloric acid processing, BA sheets developed micro-pitting in 18 months, while pickled GR2 sheets remained corrosion-free after 8 years, reducing maintenance costs by 40%.
Fabrication and Welding Guidance
- Cutting:CTL (Cut-to-Length) precision recommended; see Cut-to-Length Titanium Sheet Guide
- Forming:Avoid scratches, maintain dimensional stability
- Welding:TIG welding preferred; for thick sections, plasma welding may be used
- Post-Weld Treatment:Pickling restores passivation layer and prevents HAZ corrosion
- Inspection:Visual and chemical inspection ensures long-term reliability
Example:
A 5 m³ sulfuric acid reactor using GR2 pickled sheets underwent TIG welding with post-weld pickling. No corrosion or HAZ issues were reported 10 years post-installation, highlighting the importance of proper fabrication.
Engineering and Procurement Perspective
- Grade Selection:Match media, temperature, and pressure
- Thickness Planning:Thicker sheets for high pressure or aggressive media
- Surface Finish:Pickled for aggressive chemicals; BA for mild conditions
- Fabrication Verification:Ensure supplier can handle CTL cutting, TIG/plasma welding, and pickling
- Cost-Benefit Analysis:Slightly higher material cost offsets reduced downtime and replacement expenses
Procurement Tip: Specify titanium grade, thickness, surface finish, and post-weld treatment in RFQs for reliable fabrication.
FAQ
Q: Can BA plates withstand strong acids?
A: They are not recommended; acid-washed GR2 plates should be used instead.
Q: Is acid washing required after welding?
A: Yes, especially for acid-washed plates.
Q: Does thickness affect corrosion resistance?
A: Yes, thicker plates are more resistant to localised corrosion.
Q: What are the recommended welding methods?
A: TIG welding under inert gas protection and plasma welding for thick plates.
Q: How is post-weld passivation verified?
A: Standard chemical testing and visual inspection.
Q: Can BA plate be acid-washed after machining?
A: Yes, through acid treatment.
Conclusion and Brand Guidance
To ensure the durability and operational efficiency of chemical reactors, it is essential to select the correct titanium grade, thickness and surface finish.
At ProX Metal, we provide comprehensive support, including guidance on material selection and fabrication. We offer GR1 and GR2 Titanium Sheets, CTL cutting and welding expertise, and consultation on post-weld treatment. Chemical plants can maximise reactor lifespan, reduce maintenance and achieve long-term operational safety by combining engineering knowledge with high-quality materials.