TC4 titanium flange for pressure vessel

Product Overview

Reviewed and maintained by the Engineering Team, Shaanxi Qianyi Tuoda Technology Co., Ltd.

TC4 (Gr5 Ti-6Al-4V) Titanium Flange for Pressure Vessel | ASTM B381 F-5, ASME B16.5, Forged + CNC

Meta Description: TC4 (Ti-6Al-4V / Grade 5) Titanium Flanges for pressure vessel nozzles and closures — ASTM B381 F-5, ASME B16.5, closed-die forged + CNC, annealed, UT/PT, EN 10204 3.1. Grade confirmed against medium + temperature + WPS before PI.

TC4 in One Line (no abbreviation confusion)

• GB: TC4
• ASTM/ASME: Grade 5 / F-5 (forging), Ti-6Al-4V
• UNS: R56400 | DIN/W.-Nr.: 3.7165
• Chemistry: Ti bal., Al 5.5–6.75%, V 3.5–4.5%, O≤0.20%, Fe≤0.30%, H≤0.015%
• Annealed min: Rm≥895 MPa, Rp0.2≥828 MPa, El≥10% [1,10](@ref)
• Density ~4.43 g/cm³ — steel-beating strength at ~57% of steel weight

Certificate must say F-5 / R56400 / Ti-6Al-4V. "TC4" alone is not enough for an ASME paper trail.

When TC4 Is the Right Flange for a Pressure Vessel

• Vessel nozzle or closure where stress analysis shows CP-Ti (Gr2) wall/weight is not competitive
• High-pressure loop, skid, autoclave, reactor head, separator
• Offshore/man-lift weight budget — flange mass matters
• Fatigue / thermal-cycle duty on the connection
• Vessel shell is also Gr5 pipe/tube — grade continuity on the weld

When TC4 Is NOT the Auto-Choice

• Pure corrosion duty (seawater/oxidizing chloride, ambient T) → Gr2 is cheaper, more ductile, wider crevice margin
• Hot concentrated brine crevice → Gr7/Gr12 reviewed first
• Reducing-acid excursion → Gr7 (Pd by chemistry)
• HF / dry chlorine / red fuming nitric → titanium excluded entirely
• No qualified WPS for Ti-6Al-4V dissimilar weld → fix WPS before material moves

Pressure-Vessel Supply Scope

• Type: Weld Neck (vessel nozzle, preferred), Blind (closure/test port), LWN, orbit/long-hub on drawing
• Standard: ASME B16.5 (NPS 1/2–24); B16.47 Series A/B for large bore
• Forging: ASTM B381 F-5 / ASME SB-381
• Class: 150–600 rotating; 900–2500 forged to PO
• Face: RF / FF / RTJ (groove machined to B16.5)
• Heat treatment: anneal per B381; STA (solution treat + age) on PO only, with thermal record

Why Forged, Not Bar-Cut

1. Certified R56400 billet → heat No. locked
2. Alpha-beta die forging (controlled vs Beta transus ~995°C) — refined grain, no coarse Widmanstätten
3. Anneal + (STA if specified), furnace record retained
4. CNC: hub taper, bore, bolt circle, RF height / RTJ groove to B16.5
5. Pickle descale, ferroxyl check for iron pickup, face protected
6. Re-etch heat No. — parent heat = finished flange heat

Pressure-Vessel Acceptance Items (what the inspector wants)

• ASTM B381 F-5 MTC 3.1: measured interstitials + tensile/YS/elongation, heat-to-ingot
• UT on forging (immersion per PO/AMS clause), PT on machined face
• Dimensional report: hub, bore, bolt circle, face flatness, groove geometry
• Heat treat record (anneal or STA curve)
• PMI/XRF grade verify; Gr5 not "guessed by colour"
• Weld prep: machine bevel 37.5°, argon-clean, no steel contact
• 3.2 (SGS/BV/TÜV/DNV) PO-fronted — TPI witnesses forge + NDE, not back-built from 3.1

Welding Reality (owner/installer scope, stated up front)

• GTAW, ERTi-5 (or ERTi-23 ELI where toughness governs), full argon torch + trailing + back purge
• Weld colour accept: silver/straw; blue/purple = reject
• Dissimilar Gr2↔Gr5 joint: qualified WPS + procedure qualification required
• Post-weld stress relief common on loaded joints; PWHT per designer
• Site WPS/PQR is installer responsibility — we supply compatible bevel + cert, not the weld procedure

RFQ Template (copy-paste)

Vessel service / medium: ___
Design T: ___°C   Design P: ___bar   Code: ASME VIII / GB150 / PED ___
Flange type: WN nozzle / Blind / LWN ___
Grade confirm: TC4 = ASTM B381 F-5 / R56400 ___
NPS × SCH (bore): ___ (DN ___)
Class: 300 / 600 / ___   Face: RF / RTJ ___
Heat treat: annealed / STA ___
NDE: UT ___ / PT ___ / RT ___
Weld: same-grade Gr5 / dissimilar Gr2↔Gr5 (WPS attached?) ___
Cert: 3.1 / 3.2 (TPI ___)
Incoterm: EXW Baoji / FOB Shanghai / DAP ___

FAQ — TC4 Pressure Vessel Flange

Q1: Is TC4 accepted in ASME construction?
A: Via ASTM B381 F-5 / SB-381, UNS R56400. Drawings must call the grade by spec, not only "TC4".

Q2: WN or Blind for a vessel?
A: Nozzle = WN (stress flow + radiograph-friendly). Closure/test port = Blind. LWN when drawing specifies extended hub.

Q3: Annealed or STA?
A: Annealed is default pressure-equipment state. STA only when design intends higher strength and WPS/heat-treat record supports it.

Q4: Stronger than Gr2 — so always better?
A: Mechanically yes, metallurgically not "more corrosion-proof". Gr2 has wider reducing/crevice margin. Pick by duty, not by strength alone.

Q5: Can TC4 weld to Gr2 pipe?
A: Yes with qualified WPS (ERTi-5 or transition logic). Unqualified dissimilar Ti weld = reject risk.

Q6: UT mandatory?
A: For solid pressure-retaining forgings, yes per PO/class; 100% UT on blind, volumetric per procedure on WN.

Q7: RTJ at what class?
A: Class 600+ common; groove machined to B16.5, metal ring gasket.

Q8: Large bore vessel flange?
A: Free-forge / ring-roll from project heat, B16.47, RT per PO. Not shelf stock.

Q9: 3.2 possible?
A: TPI at PO stage. Cannot be retro-built from 3.1 after shipment.

Q10: HS code?
A: WCO 6-digit 8108.90 base; destination sub-heading via broker. Process statement supplied.

Request a Quote

Email: sales@[yourdomain].com

Send vessel code + medium + design P/T + flange type + grade confirmation. Reply in 24h: heat status, EXW/FOB price, NDE scope, MTC type, dispatch window.

About: Baoji Titanium Valley TC4/Gr5 pressure-vessel flange line — ASTM B381 F-5 (R56400 / Ti-6Al-4V), ASME B16.5, alpha-beta die forged + CNC, annealed, UT/PT, heat-traceable, EN 10204 3.1. For load-governed nozzles and closures where strength-to-weight wins. No bar-cut-as-forge, no "TC4-only" cert with no F-5 line, no grade guess, no cert downgrade. Lot confirmed before PI; tag = MTC = PL.