Overview
ASTM B338-17(2026) covers seamless and welded titanium and titanium-alloy tubes for surface condensers, evaporators and heat exchangers. A complete order identifies grade, manufacturing route, outside diameter, wall, length, heat treatment, weld condition, testing, cleanliness and equipment-design requirements.
Designation and acceptance
B338 is an equipment-service tube specification, not a general titanium pipe document. Seamless tube is cold reduced or drawn from hollow billet; welded tube is formed from flat product by automatic arc welding and receives sufficient cold work and subsequent heat treatment to transform the weld microstructure as required. Pipe size, piping-code acceptance or general welded-pipe supply must use the appropriate separate document.
Members and selection
| Designation | Selection context |
|---|---|
| Seamless tube | Choose when the design or qualification requires the seamless route and define OD, wall and cold-work/heat-treatment condition. |
| Welded tube | Require automatic weld route, final cold work, heat treatment and weld-specific examination evidence. |
| Commercially pure grades | Select for the qualified water/process environment, strength, fabrication and erosion/corrosion limits. |
| Alloy and H grades | Use only after pressure/equipment code, temperature, corrosion and property requirements are resolved. |
Comparison framework
| Criterion | Decision context |
|---|---|
| Tube vs pipe | B338 is condenser/heat-exchanger tube; similar dimensions do not turn it into B861/B862 pipe. |
| Seamless vs welded | Manufacturing history, weld presence and examination differ even when alloy and dimensions match. |
| OD and wall | Tube identity uses exact outside diameter and wall, plus tolerances and length—not only a nominal pipe schedule. |
| Material vs exchanger | B338 material compliance does not establish tubesheet design, expansion, vibration, water chemistry or equipment-code approval. |
Performance
- Acceptance under ASTM B338 Titanium Tube depends on the exact alloy or grade, delivered condition, product geometry and specified test basis rather than the standard number alone.
- Wall eccentricity, weld quality, contamination, hydride formation and handling dents can govern tube reliability.
- Service suitability remains an engineering decision: material selection alone does not solve galvanic couples, tubesheet crevice conditions, flow-induced vibration or cleaning chemistry.
Orderable product scope
- Straight seamless titanium heat-exchanger tube in exact OD, wall and length.
- Straight welded/cold-worked titanium tube with documented weld and heat-treatment route.
- Special-length or test-controlled tube lots for condensers, evaporators and exchangers.
Processing
- Keep tube bores and surfaces free from iron, oil, chlorides and handling damage.
- Qualify tube expansion, orbital welding or seal welding with the selected grade and tubesheet system.
- Control cutting, deburring, end protection and cleaning so acceptance remains valid at assembly.
Applications
- Power and industrial surface condensers after vibration and water-chemistry design.
- Desalination and process evaporators using qualified titanium grades.
- Chemical and marine heat exchangers where corrosion, erosion and joining details are engineered.
Selection
- Confirm that ASTM B338 Titanium Tube actually covers the required product form and manufacturing route before comparing grades or quotations.
- Select alloy or grade and delivered condition from service, fabrication, section size and required property evidence; do not infer condition from a trade name.
- Require a written technical comparison and responsible-engineer approval before substituting another standard, alloy, condition or product route.
Procurement
- State ASTM B338-17(2026), exact grade, seamless or welded route and required heat-treatment condition.
- State outside diameter, nominal/minimum wall basis, length, quantity, tolerances and end preparation.
- Define hydrostatic/pneumatic or NDE, flattening/flaring, weld examination, surface cleanliness and inspection document.
- Require heat/lot and weld-route traceability, tube marking or bundle identification, capped ends and dry protected packing.