Seamless vs. Welded: A Guide to Choosing Your Titanium Pipes

When specifying titanium pipes for a project, one of the first decisions is whether to use a seamless or welded product. Both have their advantages and are manufactured to strict ASTM standards, but their differences in manufacturing, performance, and cost make them suitable for different applications.

Seamless Titanium Pipes (ASTM B861)

Seamless pipes are produced by extruding or piercing a solid billet of titanium to form a hollow tube. There is no weld seam.

• Key Advantages: Superior strength under pressure and a completely uniform structure. They are considered more reliable for high-pressure and high-temperature applications.
• Best For: Critical, high-pressure systems such as aerospace hydraulic lines, high-pressure chemical reactors, and subsea systems.
• Limitations: Generally more expensive and available in a more limited range of diameters and wall thicknesses compared to welded pipes.

Welded Titanium Pipes (ASTM B862)

Welded pipes are manufactured by taking a titanium sheet or plate, rolling it into a pipe shape, and then longitudinally welding the seam.

• Key Advantages: More cost-effective, especially in larger diameters. They are available in a much wider range of sizes and can be made with thinner walls.
• Best For: The majority of industrial applications, including low-to-medium pressure chemical transport, water treatment, power plant cooling systems, and architectural uses.
• Quality Note: Modern welding and testing techniques (like eddy current and ultrasonic testing) ensure that the weld seam is high-quality and reliable for its intended service.

Comparison at a Glance

Feature	Seamless Titanium Pipe	Welded Titanium Pipe
Manufacturing	Extruded from a solid billet	Rolled from a flat sheet/plate and welded
ASTM Standard	B861	B862
Pressure Rating	Highest	Good (suitable for most industrial needs)
Cost	Higher	Lower (more cost-effective)
Size Range	More limited	Very wide range of sizes available
Common Use	High-pressure, critical systems	General industrial, large-diameter systems

Choosing the Right Grade

For both seamless and welded pipes, Grade 2 is the most common choice due to its excellent all-around corrosion resistance and good fabricability. For exceptionally corrosive environments where crevice corrosion is a concern (e.g., hot chlorides), Grade 7 (with palladium) or Grade 12 (with nickel and molybdenum) may be specified.

The Right Pipe for the Job: The choice between a seamless and welded titanium pipe comes down to application requirements: pressure, temperature, environment, and budget. For most industrial piping, modern welded pipe is the optimal choice, while seamless is reserved for the most critical duties.