ASTM B337/B337M is the standard specification by ASTM International covering seamless and welded titanium and titanium alloy pipe for corrosive service. The specification defines multiple grades of commercially pure (CP) titanium and titanium alloys — including Grade 1, Grade 2, Grade 3, Grade 4, Grade 7, Grade 9, and Grade 12 — with pipe dimensions governed by ASME B36.19M. Grade 2 is the industry standard for chemical processing, seawater, and desalination applications. The companion specification ASME SB337 adopts identical requirements for ASME Boiler and Pressure Vessel Code compliance.

Zhengzhou Huitong (HT Pipe) supplies ASTM B337 / SB337 compliant seamless and welded titanium pipe in all standard grades with full Mill Test Certificates (MTC) per EN 10204 3.1. 

1. Standard Scope & Designation

ASTM B337/B337M covers two manufacturing forms for titanium and titanium alloy pipe:

2. Grades Covered by ASTM B337

ASTM B337 covers both commercially pure (CP) titanium grades and titanium alloy grades. Grade 2 is the most widely used for general corrosion-resistant service; Grade 7 adds palladium for enhanced crevice corrosion resistance.

3. Chemical Composition (ASTM B337 Table 1)

Values are maximum unless shown as a range. Heat analysis. Ti = balance. Per ASTM B337/B337M-10.

Note: Full chemistry per ASTM B337/B337M-10 Table 1. Product analysis tolerances per ASTM B348 apply. Grade 5: Al 5.5–6.75%, V 3.5–4.5%; Grade 9: Al 2.5–3.5%, V 2.0–3.0%; Grade 12: Mo 0.2–0.4%, Ni 0.6–0.9%.

4. Mechanical Property Requirements (ASTM B337 Table 2)

All values are minimum requirements. Per ASTM B337/B337M-10. All grades supplied in annealed condition.

Note: Elongation test specimen: 2" gauge length (GL) per ASTM B338 strip specimen, or 4D (4× diameter) for round specimens. EUL = Extension Under Load method. Testing per ASTM E8/E8M.

5. Heat Treatment Requirements

6. Testing & Inspection Requirements

7. Pipe Dimensions — ASME B36.19M (Stainless Steel & Titanium Pipe)

ASTM B337 pipe dimensions follow ASME B36.19M (Stainless Steel and Titanium Pipe). Key wall thicknesses for common NPS sizes:

Note: ASME B36.19M covers titanium pipe in Schedules 5S, 10S, 20S, 40S, 80S, 120S, and 160S. Unlike B36.10M, the S-suffix schedules have thinner walls for corrosive service (no pressure design in corrosive medium). Wall thickness tolerance: OD ±0.75% (min ±0.25 mm); WT −0 / +15%.

8. Industries & Applications

9. ASTM B337 vs ASTM B861 vs ASTM B338 — Titanium Pipe & Tube Comparison

10. Related Standards

11. How to Order — Required Information

12. Frequently Asked Questions

Q: What is ASTM B337 Grade 2 titanium pipe used for?

ASTM B337 Grade 2 (UNS R50400) is the most widely specified titanium pipe for corrosive service. Key applications include seawater desalination plant piping (evaporators, brine heaters, condensate lines), offshore platform seawater cooling systems, chemical processing plant piping for hydrochloric acid, sulfuric acid, nitric acid, and organic acids, and power plant condensate and feedwater systems. Its minimum tensile strength of 344 MPa, yield of 275 MPa, and 20% elongation provide excellent structural integrity while maintaining titanium's superior corrosion resistance in oxidizing and chloride-bearing environments.

Q: What is the difference between ASTM B337 Grade 2 and Grade 7?

Grade 7 (UNS R52400) has identical mechanical properties to Grade 2 — same TS ≥ 344 MPa, YS ≥ 275 MPa, Elongation ≥ 20% — but adds 0.12–0.25% palladium. This palladium addition dramatically improves crevice corrosion resistance in chloride-bearing acids (hydrochloric acid, sulfuric acid, phosphoric acid) and seawater service where crevices are unavoidable. The rule of thumb: specify Grade 7 wherever crevice corrosion is a concern; use Grade 2 for general corrosive service where cost is a factor.

Q: What are the temperature limits for ASTM B337 titanium pipe?

CP titanium grades (Grade 1–4) are limited to approximately 315–400°C (600–750°F) for continuous service. Below 315°C, CP titanium maintains excellent corrosion resistance in most environments. At elevated temperatures above 350°C, CP titanium may experience surface oxidation and gradual strength loss. Grade 5 (Ti-6Al-4V) is limited to approximately 430°C (800°F) due to its alpha-beta microstructure. For cryogenic service, CP titanium grades maintain excellent toughness and ductility down to liquid nitrogen temperature (−196°C) and below, making them suitable for LNG applications.

Q: Can ASTM B337 welded titanium pipe withstand seawater service?

Yes. ASTM B337 Grade 2 and Grade 7 welded titanium pipe are the preferred materials for seawater service. Titanium forms a stable, passive TiO₂ film that provides outstanding corrosion resistance in seawater at temperatures up to approximately 120°C (250°F) with zero pitting, no crevice corrosion (Grade 7), and negligible corrosion rates compared to stainless steels or nickel alloys. Welded titanium pipe for seawater must use ERTi-2 filler wire for Grade 2 base metal, and both the OD and ID weld zone must be purged with argon shielding during and after welding to prevent oxidation embrittlement.

Q: Is ASME SB337 the same as ASTM B337?

Technically identical in chemical, mechanical, dimensional, and testing requirements. ASME SB337 is ASTM B337 adopted into ASME BPVC Section II Part B. The key difference is regulatory context: SB337 is used for ASME Code-stamped pressure vessels and piping where authorized inspector (AI) oversight, Certified Material Test Reports (CMTR), and material traceability are mandatory. For non-code chemical processing or offshore piping, ASTM B337 is sufficient. Most titanium pipe mills supply dual-certified B337/SB337 material.

Request a Quote — ASTM B337 Seamless & Welded Titanium Pipe

Zhengzhou Huitong (HT Pipe) supplies ASTM B337 / SB337 Grade 1, 2, 3, 4, 7, 9, and 12 seamless and welded titanium pipe in all standard schedules. Full EN 10204 3.1 CMTRs and competitive lead times from affiliated titanium mills.