GR1 Titanium Tube for Heat Exchangers
Jun 30, 2026
GR1 Titanium Tube vs 304/316L Stainless Steel
| Material | Pitting Resistance Equivalent Number (PREN) | Seawater Corrosion Rate (mm/year) | Crevice Corrosion Temperature (°C) | Stress Corrosion Cracking Risk |
|---|---|---|---|---|
| GR1 Titanium | Not applicable (passive film self-healing) | < 0.001 | > 80°C | Extremely low |
| 304 Stainless Steel | ~19 | 0.05 – 0.10 | < 10°C | High above 60°C |
| 316L Stainless Steel | ~25 | 0.02 – 0.05 | < 15°C | Moderate above 60°C |
| 90/10 Cu-Ni | Not applicable | 0.01 – 0.02 | < 40°C | Low |
| Titanium Grade 2 | Not applicable | < 0.001 | > 80°C | Extremely low |
GR1 titanium does not rely on chromium or molybdenum for corrosion resistance - it forms a stable, continuous, and self-healing titanium dioxide (TiO₂) passive film that remains intact even when mechanically damaged. This film is stable in seawater up to 80°C and provides virtually unlimited service life in chloride environments. For power plant condensers using seawater as cooling medium, GR1 titanium seamless pipe has become the industry standard.
Thermal Conductivity vs. Corrosion Resistance
| Material | Thermal Conductivity (W/m·K) | Typical Wall Thickness (mm) | Fouling Resistance (m²·K/W) | Overall U-Value (W/m²·K) - Water/Water |
|---|---|---|---|---|
| Copper / Cu-Ni | ~380 | 1.2 – 1.6 | Moderate (0.0002) | ~2,500 – 3,000 |
| 316L Stainless Steel | ~16 | 0.9 – 1.2 | Moderate (0.0002) | ~1,800 – 2,200 |
| GR1 Titanium | ~17 | 0.5 – 0.9 | Very Low (0.00005) | ~2,200 – 2,800 |
Why choose GR1 titanium?
Thinner walls can be used because titanium's corrosion resistance eliminates the need for corrosion allowance
Lower fouling tendency due to smooth, oxide-free surface - biofouling and scaling are significantly reduced
Higher tube-side velocity can be tolerated (up to 3.5 m/s in seawater) without erosion-corrosion concerns
Dimensions and Standard Sizes
| Outer Diameter (OD) | Wall Thickness (WT) | Typical Application | Standard Length |
|---|---|---|---|
| 12.7mm (1/2 inch) | 0.70mm, 0.89mm | Small condensers, evaporators | 3m – 6m |
| 15.88mm (5/8 inch) | 0.89mm, 1.09mm | Medium heat exchangers, chillers | 4m – 8m |
| 19.05mm (3/4 inch) | 0.89mm, 1.09mm, 1.24mm | Standard heat exchangers | 4m – 10m |
| 25.4mm (1 inch) | 0.89mm, 1.09mm, 1.24mm, 1.65mm | Large condensers, process exchangers | 4m – 12m |
| 31.75mm (1.25 inch) | 1.09mm, 1.24mm, 1.65mm | High-flow applications | 4m – 12m |
| 50.8mm (2 inch) | 1.24mm, 1.65mm, 2.11mm | Evaporators, large process exchangers | 4m – 15m |
For custom heat exchanger bundles, we offer precision cut-to-length GR1 titanium tubing up to 15 meters with OD tolerance ±0.08mm and wall thickness tolerance ±10%. We also provide tube-end preparation including beveling, deburring, and polishing to facilitate smooth tube rolling and expansion into tube sheets.
What Can Go Wrong With Heat Exchanger Tubes?
| Real Failure Scenario | Root Cause | Our QC Countermeasure | Test Method |
|---|---|---|---|
| Tube splits during rolling into tube sheet | Material too hard / insufficient ductility | Flattening + Flare test on every heat - we reject if any cracking appears at 2x OD flattening | ASTM B338 mechanical tests |
| Pinhole leak develops after 6 months in seawater | Subsurface inclusion not caught by standard UT | Rotating-probe Eddy Current (ET) with 100% coverage - detects flaws as small as 0.1mm | Internal ET standard for all heat exchanger orders |
| Tube ends corrode at the tube sheet crevice | Surface contamination from mill oil / residue | Ultrasonic degreasing + hot DI water rinse - removes all organic residues before packaging | Water break test + UV inspection |
| Tube vibrates and frets at support baffles | Residual stress from cold drawing causing micro-movement | Stress relief annealing verified by X-ray diffraction (residual stress < 50 MPa) | XRD residual stress measurement on sample |
Our Factory
| Metric | Our Performance | |
|---|---|---|
| Annual heat exchanger tube output | 850+ tons (GR1 + GR2) | We have run multiple large projects simultaneously - no bottlenecks |
| Cold pilgering speed (typical) | 8–12 meters/minute | Faster throughput = shorter lead times for your bundle |
| Maximum tube length (single piece) | 18 meters | Fewer welds in your heat exchanger = lower leak risk |
| Wall thickness consistency (heat-to-heat) | ±8% of nominal | Predictable rolling behavior - no surprises in your tube sheet |
| Lead time for standard sizes | 3 working days (stock) / 18 days (custom) | Faster project completion - you get paid sooner |
| Number of VAR melts per year | 120+ heats | High melt frequency = fresher material, better traceability |
FAQ
Q1: Why choose GR1 titanium tube over GR2 for heat exchanger applications?
Answer: GR1 offers superior formability for tube rolling and expansion - its lower yield strength (170–310 MPa vs 275–450 MPa for GR2) makes it significantly easier to roll into tube sheets without cracking. For heat exchangers that require extensive tube rolling, flaring, or bending, GR1 is the preferred grade. GR2 may be selected if higher strength is required for thin-wall designs.
Q2: What is the maximum seawater temperature for GR1 titanium condenser tubes?
Answer: GR1 titanium tubes can handle seawater temperatures up to 80°C (176°F) without risk of crevice corrosion or pitting. At temperatures above 80°C, the passive film remains stable, but the risk of hydrogen absorption increases if cathodic protection is not properly controlled. For desalination plants operating at higher temperatures, we recommend Grade 2 or Grade 7 titanium.
Q3: Can GR1 titanium heat exchanger tubes be welded to titanium tube sheets?
Answer: Yes, GR1 titanium tubes can be welded to titanium tube sheets using GTAW (TIG) welding with 100% argon shielding. The weld joint must be purged with argon on the root side to prevent embrittlement. We recommend using GR1 or GR2 filler wire for weld matching. Post-weld inspection should include dye penetrant testing or pneumatic leak testing to verify weld integrity.
Q4: What is the difference between seamless and welded GR1 titanium tubing for heat exchangers?
Answer: Seamless GR1 tubes are produced by rotary piercing and cold drawing - they have no weld seam and are preferred for high-pressure or high-integrity heat exchangers (e.g., nuclear, chemical reactors). Welded-and-drawn GR1 tubes are formed from strip, welded, and then cold-drawn to final dimensions - they offer more uniform wall thickness, better concentricity, and lower cost, making them ideal for large power plant condensers. Both are ASTM B338 compliant.
Q5: What eddy current testing (ET) standards do you apply to heat exchanger tubes?
Answer: We perform eddy current testing per ASTM E426 and ASME Section V requirements. For heat exchanger tubes, we use a rotating probe system to achieve ≥ 90% coverage of the tube surface. Defects are evaluated against acceptance criteria per SA-213 / SA-249 - typically, any flaw exceeding 5% of wall thickness is flagged for rejection or further evaluation.
Q6: Do you provide tube rolling and expansion test reports?
Answer: Yes, upon request we provide tube expansion test reports as part of our MTR package. We perform flattening tests, flare tests, and expansion tests on samples from each heat to verify that the GR1 titanium tube can withstand the deformation required during tube-to-tubesheet rolling. These tests are conducted per ASTM B338 requirements.
