Price Comparison
Titanium costs 3-5x more than C71500. This is not a small gap.
Market prices (ex-works, May 2026):
| Size | C71500 Copper Nickel | Titanium Grade 2 |
|---|---|---|
| 1" x 14 BWG per ton | $11,000-12,000 | $35,000-50,000 |
| 1" x 14 BWG per foot | ~$4.80 | ~$18-22 |
| 2" x SCH 10 per foot | ~$10.00 | ~$40-50 |
| 4" x SCH 10 per foot | ~$32.00 | ~$130-160 |
What this means for a real project. Take a 200-foot seawater line with 4" SCH 10 pipe and 8 flanges:
| Item | C71500 | Titanium Grade 2 |
|---|---|---|
| Pipe (200 ft) | $6,400 | $26,000-32,000 |
| Flanges (8 pcs) | $1,600 | $7,000-8,000 |
| Gaskets and bolts | $400 | $1,000 |
| Material subtotal | $8,400 | $34,000-41,000 |
Titanium costs 4-5x more for materials alone. Before welding. Before shipping. Before installation.
For ASTM B111 C70600 copper nickel pipe, the gap is even wider because C70600 is 15-20% cheaper than C71500.
Corrosion Resistance Comparison
General corrosion rates in seawater:
| Material | Corrosion rate (mm/year) | 20-year loss |
|---|---|---|
| Titanium Grade 2 | ~0.001 mm/yr or less | Negligible (<0.02 mm) |
| C71500 | ~0.025 mm/yr | ~0.5 mm (0.020") |
What this means in practice:
Titanium pipe will never corrode through. It outlasts your plant.
C71500 pipe with 13 BWG wall (0.095" / 2.41 mm) loses about 0.020" over 20 years. It still has 0.075" left. Plenty of strength.
Specific corrosion types:
| Corrosion type | C71500 | Titanium Grade 2 |
|---|---|---|
| General seawater corrosion | Excellent | Excellent (better) |
| Crevice corrosion | Resistant | Resistant (Grade 7 even better) |
| Pitting in stagnant seawater | Resistant | Resistant |
| Chloride SCC | Resistant | Resistant |
| Erosion-corrosion | Good up to 4-6 m/s | Excellent up to 10-15 m/s |
Biofouling Comparison
| Biofouling aspect | C71500 | Titanium Grade 2 |
|---|---|---|
| Barnacle attachment | Prevents (copper ions kill larvae) | Attaches freely |
| Algae growth | Prevents | Grows |
| Mussel colonization | Prevents | Colonizes |
| Need for antifouling coating | No | Yes |
| Cleaning frequency | Annual inspection only | Monthly to quarterly |
Why C71500 works: Copper ions slowly release from the pipe surface. Barnacle larvae die on contact. Algae does not grow. The pipe stays clean.
What happens to titanium: No copper. Marine organisms attach and grow. Within 6-12 months, barnacles can reduce flow by 20-30%. Within 2 years, 40-50% flow loss is possible.
Real example: A desalination plant in the Middle East installed titanium intake pipes. After 8 months, barnacle growth reduced flow by 35%. They had to shut down and install a copper ion anode system. Total cost exceeded C71500 by 6x.
Velocity and Temperature Limits
Velocity limits:
| Velocity range | C71500 | Titanium Grade 2 |
|---|---|---|
| 0-3 m/s | Excellent | Excellent |
| 3-4 m/s | Excellent | Excellent |
| 4-6 m/s | Good (film erodes near 6 m/s) | Excellent |
| 6-10 m/s | Marginal – not recommended | Excellent |
| >10 m/s | Do not use | Acceptable with design care |
Temperature limits:
| Temperature range | C71500 | Titanium Grade 2 |
|---|---|---|
| <50°C | Excellent | Excellent |
| 50-80°C | Excellent | Excellent |
| 80-100°C | Acceptable | Excellent |
| 100-120°C | Acceptable (derate pressure) | Excellent |
| 120-150°C | Not recommended | Acceptable |
| >150°C | Do not use | Acceptable (Grade 2 to ~200°C) |
Sand and erosion resistance:
| Condition | C71500 | Titanium Grade 2 |
|---|---|---|
| Clean seawater | Excellent | Excellent |
| Trace sand (<0.1%) | Good | Excellent |
| Moderate sand (0.1-0.5%) | Fair – needs thicker wall | Good |
| High sand (>0.5%) | Poor – need filters | Fair – still erosive |
Fabrication and Welding Comparison
| Fabrication aspect | C71500 | Titanium Grade 2 |
|---|---|---|
| Cutting | Standard saw or abrasive wheel | Standard tools, slower speed |
| Bending | Standard pipe bender, 3x OD radius | Requires special tooling, larger radius |
| Welding process | TIG with argon back purge | TIG with extreme care |
| Welding environment | Shop or field | Clean room conditions preferred |
| Back purge requirement | Yes (argon) | Yes (high purity argon) |
| Weld contamination sensitivity | Low | Very high (oxygen, nitrogen, hydrogen all cause embrittlement) |
| Post-weld cleaning | Standard | Pickling or special procedures |
| Field welding possible | Yes, with portable argon | Difficult – requires tent, humidity control |
| Welder certification | Standard pipe welder | Special titanium certification |
Availability and Lead Time Comparison
| Availability factor | C71500 | Titanium Grade 2 |
|---|---|---|
| Number of global mills | Many (20+) | Few (5-10) |
| Distributor stock | Widely available | Limited |
| Common sizes (1-4" SCH 10/40) | Usually in stock | Rarely in stock |
| Lead time – stock sizes | 1-5 days | 4-8 weeks if available |
| Lead time – mill order | 4-12 weeks | 12-20 weeks |
| Minimum order quantity | 1 ton (stock) or 5 tons (mill) | Often 5-10 tons |
| Small quantity availability | Yes, from distributors | Difficult, expensive |
Weight Comparison
| Property | C71500 | Titanium Grade 2 |
|---|---|---|
| Density (g/cm³) | 8.94 | 4.51 |
| Weight of 4" SCH 10 pipe per foot | ~6.2 lbs | ~3.1 lbs |
| Weight of 100 ft of 4" SCH 10 | ~620 lbs | ~310 lbs |
When this matters:
Offshore platforms with weight limits
Submarine or shipboard weight-sensitive designs
Mobile equipment
Long spans with limited support
When this does not matter:
Land-based installations
Most ships (weight is not usually the constraint)
Buried pipelines
When to Choose Titanium
| Condition | Threshold | Why titanium wins |
|---|---|---|
| High velocity | >6 m/s continuous | C71500 film erodes |
| High temperature | >120°C | C71500 degrades |
| Significant sand | >0.1% by weight | C71500 erodes |
| Weight critical | Structure limited | Titanium is 50% lighter |
| Zero copper | Nuclear / pharma | C71500 releases copper ions |
| No biofouling concern | Cold, flowing, clean water | Titanium does not foul as badly |
| Unlimited budget | - | Titanium is better technically |
When to Choose C71500
| Condition | Why C71500 wins |
|---|---|
| Seawater is warm (>20°C) | Biofouling risk – C71500 resists, titanium fouls |
| Flow is intermittent | Stagnant water increases biofouling – C71500 resists |
| Normal velocity (2-4 m/s) | C71500 handles this perfectly |
| Normal temperature (<80°C) | C71500 lasts 20-40 years here |
| Budget matters | C71500 costs 1/4 to 1/5 of titanium |
| Need pipe in <8 weeks | Titanium lead times are long |
| Local welders are not titanium-certified | C71500 uses standard welding |
| You will not clean pipes monthly | C71500 self-cleans via copper ions |
FAQ
Q1: Is titanium better than C71500?
Technically yes. It corrodes less and handles higher velocity and temperature. But for most applications, you do not need that extra performance. C71500 is good enough at 1/4 the cost.
Q2: Why do most ships use C71500 instead of titanium?
Two reasons. Cost (C71500 is much cheaper) and biofouling (titanium grows barnacles, C71500 does not). Ships also need field repairable materials. Titanium welding is difficult in a shipyard.
Q3: Does C71500 corrode in seawater?
Yes, but very slowly. About 0.025 mm per year. A 13 BWG pipe loses 0.020" of wall over 20 years. That leaves plenty of strength.
Q4: Does titanium corrode in seawater?
Almost zero. Less than 0.001 mm per year. Titanium pipe will outlast your plant.
Q5: Which one handles sand better?
Titanium. It has better erosion resistance. But if you have sand, you should install filters regardless of material.
Q6: Which one is easier to weld?
C71500. Standard TIG with argon back purge. Any pipe welder can do it. Titanium requires clean rooms and certified welders.
Q7: Can I weld C71500 directly to titanium?
No. Galvanic corrosion and metallurgical issues. Use a flanged joint with isolation gasket (PTFE).
Q8: Which one is used in most desalination plants?
C71500 for brine heaters and most sections. Titanium is sometimes used for the hottest sections or for special projects. C71500 is the industry standard.
Q9: Is ASTM B111 C70600 copper nickel pipe closer to titanium in performance?
No. C70600 has lower nickel content (10% vs 30%). It has lower velocity and temperature limits than C71500. The gap to titanium is even wider.
Q10: What is your final recommendation for a typical seawater cooling system?
Buy C71500. It works. It is available. It costs 1/4 of titanium. It does not grow barnacles. Only buy titanium if you have high velocity (>6 m/s), high temperature (>120°C), weight constraints, or a no-copper rule.
