Why titanium is the best choice for seawater heat exchange
Titanium forms a tightly adherent oxide film on its surface that immediately reforms if damaged. This film makes titanium completely resistant to corrosive attack in seawater and all natural environments.
| Material | Limitation in Seawater |
|---|---|
| Copper alloy | Prone to erosion-corrosion at high velocities |
| Stainless steel | Susceptible to pitting and crevice corrosion in chlorides |
| Titanium | Excellent – no pitting, no crevice corrosion, no SCC |
Advantages of thin-wall titanium tube for heat exchangers
| Higher heat transfer efficiency | Thinner wall means lower thermal resistance and faster heat exchange |
| Lower material cost | Titanium is expensive; thinner wall reduces titanium volume per meter |
| Lighter weight | Easier handling, lower shipping cost, reduced structural support requirements |
| Sufficient strength | For heat exchanger duty (low to medium pressure), thin wall is fully adequate |
| Better formability | Thin-wall gr1 titanium tube is easier to bend into U-shapes |
Recommended titanium grades for seawater heat exchange
| Grade 1 | R50250 | Softest, highest ductility (24% elongation), best formability | Best for bending and U-tubes |
| Grade 2 | R50400 | Higher strength (275 MPa yield), good formability (20% elongation) | Most common, good all-around |
| Grade 7 | R52400 | Grade 2 + 0.12-0.25% palladium, superior crevice corrosion resistance | For high-risk applications |
Specifications for thin-wall titanium heat exchanger tubes
| Parameter | Typical Range |
|---|---|
| Standard | ASTM B338 / ASME SB338 |
| Grade | Gr.1 (UNS R50250), Gr.2 (UNS R50400) |
| Outer Diameter (OD) | 12.7 mm (1/2") to 50.8 mm (2") |
| Wall Thickness (thin-wall) | 0.5 mm to 1.5 mm |
| Length | Customized per customer requirement (up to 30 meters) |
| Form | Straight tube or U-bent tube |
| Type | Seamless or welded (cold worked, annealed) |
Applications for thin-wall titanium tubes in seawater
| Industry | Application |
|---|---|
| Power Plants | Seawater condensers, cooling water heat exchangers |
| Desalination Plants | Brine heaters, evaporators, condensers |
| Chemical Processing | Coolers using seawater as cooling medium |
| Marine / Shipbuilding | Engine cooling systems, auxiliary coolers |
| Offshore Platforms | Seawater cooling systems |
| LNG Terminals | Seawater vaporizers |
FAQ
1. What grade of titanium is best for seawater heat exchangers?
Gr1 titanium tube (UNS R50250) is best for U-bending due to its 24% elongation. Grade 2 is also suitable but less formable. Both offer excellent seawater corrosion resistance.
2. How long does titanium tube last in seawater?
Titanium tube typically lasts 20-30 years in seawater service. The self-repairing oxide film prevents pitting, crevice corrosion, and SCC that affect copper and stainless steel.
3. What wall thickness is recommended for titanium heat exchanger tubes?
For seawater heat exchange, thin-wall from 0.5mm to 1.5mm is sufficient. Thinner wall means lower thermal resistance and higher heat transfer efficiency.
4. Can welded titanium tube be used in seawater?
Yes. ASTM B338 welded tube is fully accepted for seawater heat exchangers. The weld must be cold worked and annealed, with 100% eddy current testing required.
5. Titanium vs Cu-Ni 90/10 for seawater – which is better?
Titanium is far superior. Cu-Ni suffers erosion-corrosion at high velocities. Titanium has no velocity limit, no pitting risk, and 2-3x longer service life.
6. What is the minimum bending radius for thin-wall titanium tube?
For thin-wall gr1 titanium tube, minimum cold bend radius is 1.5-2.0 x OD without mandrel. Annealed condition is best for tight bends.
7. Is titanium tube expensive compared to copper or stainless steel?
Initial cost is higher. But thin-wall design reduces material volume, and 20-30 year service life with zero corrosion makes titanium more cost-effective long-term.
8. What testing is required for titanium heat exchanger tubes?
Eddy current testing (ECT) for welded tubes, ultrasonic testing (UT) for seamless tubes, hydrostatic test, flattening test, flaring test, and tensile test.
9. Can titanium tube be used for U-bent heat exchangers?
Yes. Gr1 titanium tube is ideal for U-bending due to its 24% elongation. Use mandrel bending for thin-wall tubes to prevent ovality.
10. What is the difference between Grade 1 and Grade 2 titanium for seawater?
Grade 1 has lower yield strength (170 MPa vs 275 MPa) but higher elongation (24% vs 20%). Both have excellent corrosion resistance. Choose Gr.1 for bending; Gr.2 for straight tubes.
11. Does titanium rust or corrode in seawater?
No. Titanium forms a tightly adherent oxide film that immediately reforms if damaged. It is completely resistant to corrosion in seawater and all natural environments.
12. Can I get a sample of thin-wall titanium tube for testing?
Yes. Free samples are available for customer testing. You pay only the shipping cost. Contact us with your required OD and wall thickness.
Inspection and testing for thin-wall titanium tubes
| Test | Purpose |
|---|---|
| Eddy Current Testing (ECT) | Mandatory for welded tubes; detects flaws |
| Ultrasonic Testing (UT) | For seamless tubes |
| Hydrostatic Test | Pressure integrity verification |
| Flattening Test | Ensures ductility |
| Flaring Test | Ensures expansion capability |
| Tensile Test | Confirms yield strength and elongation |
| Chemical Analysis | Verifies titanium grade 1 composition |
GNEE provides: Mill Test Certificates (EN 10204 3.1), third-party inspection (SGS, BV, etc.) upon request.
Every shipment from GNEE includes complete test reports. Fast delivery gr1 titanium without compromising quality.
Packaging
GNEE ensures your gr1 titanium tube arrives in perfect condition for heat exchanger fabrication.
| Packaging Method | GNEE Standard Practice |
|---|---|
| Individual wrapping | Each tube wrapped in plastic film or VCI paper |
| End caps | Plastic caps on both ends – prevents debris and moisture |
| Bundling | Steel straps with rubber/cardboard padding – no tube damage |
| Wooden boxes | Export-standard plywood boxes, heat-treated, seaworthy |
| Labeling | Grade, heat number, OD, wall thickness, length, PO number |
| Custom packaging | Available per customer request |
GNEE factory equipment
GNEE is a professional gr1 titanium tube factory with full in-house production capabilities for thin-wall seawater heat exchanger tubes.
| Equipment | GNEE Specification | Capability |
|---|---|---|
| Cold pilger mill | 3 lines | Seamless tube: OD 6-102mm, wall thickness 0.5-20mm |
| TIG welding line | 2 lines | Welded tube: OD 6-1219mm, thin-wall 0.3-5mm |
| Vacuum annealing furnace | 2 units | Stress relief and recrystallization – ensures 24% elongation |
| Straightening machine | 3 units | Precision straightening for heat exchanger assembly |
| Eddy current tester | 2 units | 100% NDT for welded tubes |
| Ultrasonic tester | 1 unit | For seamless tube inspection |
| Hydrostatic tester | 2 units | Pressure test up to 200 bar |
| U-bending machine | 1 unit | Gr1 titanium forming/bending for U-tube heat exchangers |
| CNC cutting & end finishing | 2 units | Precise length cutting, end deburring |
SGS Certified Titanium Tube Manufacturer
GNEE is an SGS certified manufacturer of titanium. Our quality management system and production processes are regularly audited by SGS, one of the world's leading inspection, verification, testing, and certification companies.
