ASTM B363 Titanium Fittings: Elbows, Tees, Reducers & Stub Ends Guide

Published by Engineering Team, Shaanxi Qianyi Tuoda Technology Co., Ltd on 2026-10-21

ASTM B363 Titanium Fittings: Elbows, Tees, Reducers, Crosses & Stub Ends — Specification Guide

Table of Contents

• 1. What Is ASTM B363?
• 2. WPT vs WPR: Seamless vs Welded Fitting Grades
• 3. Fitting Types: Elbow, Tee, Reducer, Stub End, Cross
• 4. Elbow Radii: Long Radius vs Short Radius
• 5. Wall Thickness Matching: Sch 5S to 80S
• 6. How Titanium Fittings Are Made
• 7. NDT, Hydrostatic & Dimensional Inspection
• 8. How to Write an ASTM B363 RFQ
• 9. Fitting Specification Mistakes
• 10. Our Fitting & Spool Fabrication
• 11. FAQs
• 12. Related Standards

1. What Is ASTM B363?

ASTM B363 is the standard specification for titanium and titanium alloy butt-weld fittings. It covers elbows, tees, reducers (concentric and eccentric), crosses, stub ends, caps, and return bends used in welded piping systems.

The ASME version is SB-363, referenced in ASME B31.3 (Process Piping) and B31.1 (Power Piping). B363 fittings are designed to be butt-welded directly to B861 seamless pipe or B862 welded pipe of matching nominal size and schedule.

B363 = butt-weld fittings. If you need threaded, socket-weld, or flanged fittings, those are a different product category (and typically custom-machined from bar or forged blanks).

2. WPT vs WPR: Seamless vs Welded Fitting Grades

ASTM B363 uses a dual-letter prefix system that tells you both the material grade and the manufacturing method:

Rule: For elbows and tees up to NPS 6", WPT (seamless) is common. Above NPS 6", WPR (welded) becomes the practical choice because seamless starting stock in large sizes is scarce and expensive.

3. Fitting Types: Elbow, Tee, Reducer, Stub End, Cross

4. Elbow Radii: Long Radius vs Short Radius

Example: NPS 4" elbow — LR center-to-end = 152 mm (6"); SR = 102 mm (4"). For titanium, LR is almost always specified because the smoother bend reduces erosion-corrosion at the extrados in high-velocity seawater or slurry service.

5. Wall Thickness Matching: Sch 5S to 80S

B363 fittings are dimensioned per ASME B16.9 (factory-made wrought butt-welding fittings). Wall thickness is designated by schedule:

• Sch 5S: thin-wall, low-pressure, large diameters
• Sch 10S: general service (most common for titanium)
• Sch 40S: standard pressure
• Sch 80S: high-pressure, mechanical strength

Critical rule: The fitting wall must be equal to or greater than the connecting pipe wall. Never specify a Sch 5S fitting on a Sch 40S pipe — the fitting becomes the weak point.

For eccentric reducers, specify face-up or face-down orientation when used for pump suction or instrument connections.

6. How Titanium Fittings Are Made

1. Material selection: Seamless tube (WPT) or plate/strip (WPR) per B861/B862/B265.
2. Hot forming: Induction heating or furnace heating in inert/protective atmosphere; elbows pushed over mandrel, tees extruded or welded-branch, reducers hot-pressed.
3. Welding (WPR only): Longitudinal seam welded by GTAW/PAW with argon shielding; trim and blend weld bead.
4. Heat treatment: Full-body anneal (650–760°C) to restore ductility and relieve forming stress.
5. Surface treatment: Pickling/descaling to remove α-case from hot forming.
6. Sizing & straightening: Cold sizing to ASME B16.9 tolerances.
7. Final NDT: ET, UT, PT, dimensional check, visual.

Hot forming titanium without proper atmosphere control or post-form pickling leaves a brittle α-case layer that will crack in service. Always confirm your supplier pickles after forming.

7. NDT, Hydrostatic & Dimensional Inspection

WPT (seamless) fittings typically get PT + VT + dimensional. WPR (welded) fittings add ET on the seam and may require UT.

8. How to Write an ASTM B363 RFQ

Weak: "Titanium elbow 90 degree 3 inch"

Strong: ASTM B363 WPT-2 titanium 90° long-radius elbow, NPS 3", Sch 10S, annealed, pickled, PT per ASTM E165, dimensional per ASME B16.9, EN 10204 3.1

Must specify:

1. Standard: ASTM B363 / ASME SB-363
2. Grade: WPT-2 / WPR-2 / WPT-5 / WPR-5 / WPT-7 / WPR-12 etc.
3. Type: elbow / tee / reducer / stub end / cross / cap
4. Size: NPS and schedule (or exact dimensions)
5. Angle / configuration: 90° LR, 45° SR, equal tee, concentric reducer, etc.
6. Wall thickness: matching schedule
7. Ends: beveled (for butt weld)
8. Condition: annealed, pickled
9. NDE: PT / ET / UT / hydrostatic
10. Certificate: 3.1 / 3.2

9. Fitting Specification Mistakes

10. Our Fitting & Spool Fabrication

• ASTM B363 / SB-363 WPT-2, WPR-2, WPT-5, WPR-5, WPT-7, WPR-12
• NPS ½" through 24", Sch 5S through 80S
• Elbows (90°/45°/180°), tees, reducers, stub ends, caps, crosses
• Hot-formed in inert atmosphere; full-body anneal; pickled
• 100% PT + VT; ET on WPR; UT on request
• Spool assembly: fitting + pipe + flange pre-welded
• Orbital GTAW welding with argon backing; WPS/PQR qualified
• Dimensionally verified per ASME B16.9
• EN 10204 3.1 / 3.2; heat-number traceable

We supply installation-ready titanium spools — fittings welded to pipe, hydrotested, and packed for export.

11. FAQs

Q: Can B363 fittings be used with carbon-steel flanges?

Technically yes, but it creates a galvanic couple. If you must, use dielectric isolation (gasket, sleeve) or specify Titanium Flanges per ASME B16.5.

Q: What's the difference between B363 and B16.9?

B363 is the material standard (titanium grades, manufacturing, testing). ASME B16.9 is the dimensional standard (size, shape, tolerance). You need both.

Q: Are titanium stub ends reusable?

Yes. The stub end is welded to the pipe; the lap-joint flange is loose and can be rotated for bolt alignment. The stub end itself is not typically reused once welded and cut.

Q: Can I get custom angles (e.g., 22.5°, 60°, 120°)?

Yes. Custom-angle elbows are made to order. Lead time is typically 2–4 weeks additional.

Q: Do B363 fittings need post-weld heat treatment after installation welding?

No. CP titanium (Gr.1–4) does not require PWHT. Ti-6Al-4V (Gr.5) may need stress relief depending on service — confirm with your welding engineer.

12. Related Standards

• ASTM B861 Titanium Seamless Pipe — matching pipe for butt-weld fittings
• ASTM B862 Titanium Welded Pipe — large-diameter matching pipe
• ASTM B381 Titanium Forgings — forged flange blanks for spool assemblies
• ASTM B863 Titanium Wire — ERTi filler for fitting-to-pipe welding
• ASTM B348 Titanium Bar — custom-machined fitting stock
• ASTM B265 Titanium Plate, Sheet & Strip — plate source for WPR fittings
• ASTM B338 Titanium Heat Exchanger Tubes — tube-side equipment connected by fittings
• Titanium Standards Hub — all ASTM/ASME titanium articles
• ASME B16.5 Titanium Flanges — flange dimensions & facing, coming soon

Request ASTM B363 Titanium Fitting Quote

Send us:

• Type & grade (WPT-2 / WPR-2 / WPT-5 etc.)
• Size & schedule (NPS × Sch)
• Angle / configuration
• Quantity
• NDE requirements (PT / ET / UT)
• Certificate (3.1 / 3.2)

We reply within 4 business hours with availability, pricing, and lead time.