Gr2 Titanium Flange ANSI B16.5 ASTM B381

Product Overview

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

Gr2 Titanium Flange Stock, ANSI B16.5 | ASTM B381 F-2 (WPT2 / R50400), WN/SO/Blind, MTC 3.1

Meta Description: Gr2 titanium flange stock to ANSI/ASME B16.5 — ASTM B381 F-2 (WPT2 / UNS R50400 / 3.7035), weld neck / slip-on / blind, Class 150–600, RF/FF/RTJ, forged + CNC machined, pickled, heat-traceable, EN 10204 3.1. Rotating small-bore stock; large bore forged to PO.

Grade Identity (write it all on the tag)

• Gr2 = CP Titanium Grade 2
• Forging spec: ASTM B381 Grade F-2
• Fitting/pipe equivalence: WPT2 (B363 family logic)
• UNS: R50400 | DIN/W.-Nr.: 3.7035
• Density ~4.51 g/cm³ (≈57% of steel weight)

One grade, four names — RFQ can use any of them; we confirm against chemistry, not the label habit.

Flange Types in Rotating Scope

• Weld Neck (WNRF) — critical/high-pressure lines, tapered hub
• Slip-On (SORF) — utility/seawater transfer, Class 150/300 default
• Blind — end closure, spectacle blind on request
• Lap Joint — pairs with titanium stub end
• Socket Weld / Threaded — low-pressure accessory, PO-only

Standard & Dimension

• Dimensions: ASME/ANSI B16.5 (NPS 1/2–24), B16.47 Series A for large bore
• Forging: ASTM B381 / ASME SB381 (F-2)
• Facing: RF default; FF / RTJ on request (RTJ common Class 600+)
• Class: 150 / 300 / 600 rotating; 900–2500 forged to PO
• Bore: matched to SCH 10S/40S pipe; custom bore per isometric

Stock Reality (honest, no phantom shelf)

"In stock" = forged blank/rough-turned heat confirmed + CNC ready + MTC draft. Not "every class every face same day".

Manufacturing Route (why it seals)

1. Certified Gr2 billet → heat No. locked
2. Closed-die forging (ASTM B381 F-2)
3. Annealed + stress-relieved (alpha structure restored)
4. CNC turn: OD, bolt circle, hub taper, bore, RF height per B16.5
5. Pickled descale, passivation look, plastic face cover
6. Etch tag: B381 F-2 / WPT2 / R50400 / Class / Size / Heat XXX

Face & Sealing Notes

• RF serrated finish typical; smooth/FF on request
• RTJ groove machined to B16.5 groove dimensions, no hand-finishing
• No steel brush, no iron pickup on sealing face
• PE wrap + foam ring on RF face + plywood case

Where Gr2 Flange Is the Right Call

• Seawater intake / RO reject / cooling water
• Desalination channel head & brine header (ambient–moderate T)
• Wet chlorine / hypochlorite / chlor-alkali
• Oxidizing acid (nitric, mild sulfuric at low conc/temp)
• Heat exchanger nozzle + stub-end lap joint

When Gr2 Flange Is NOT Enough

• Hot concentrated brine >~80°C crevice → Gr7 or Gr12
• Reducing acid excursion → Gr7 (Pd)
• High-strength requirement → Gr5 (matched WPS, not corrosion-default)
• HF / dry chlorine / red fuming nitric → titanium excluded

Inspection & Cert

• PMI/XRF grade verification (Gr2 chemistry, not label)
• UT on forging, PT on machined face
• Dimensional: OD / bolt circle / thickness / bore / hub taper per B16.5
• EN 10204 3.1: measured O/H/N/C/Fe, tensile, heat-to-ingot
• 3.2 (SGS/BV/TÜV/DNV) PO-fronted

Export Docs & Pack

• CI + PL (heat-referenced)
• MTC 3.1 + PT/UT summary + dimensional report
• COO on request
• HS reference: WCO 6-digit 8108.90 base; destination sub-heading via broker
• ISPM-15 case, face protected, bolt holes oil-free

RFQ Template (copy-paste)

Flange type: WN / SO / Blind / Lap Joint ___
Standard: ASME B16.5
Grade: Gr2 (ASTM B381 F-2 / WPT2 / R50400)
NPS × SCH (bore): ___ (DN ___)
Class: 150 / 300 / 600 / ___
Face: RF / FF / RTJ ___
Qty: ___ pcs
Cert: 3.1 / 3.2 (TPI ___)
Incoterm: EXW Baoji / FOB Shanghai / DAP ___
Destination: ___

FAQ — Gr2 Titanium Flange Stock B16.5

Q1: Is Gr2 same as WPT2 / F-2 / R50400?
A: Same CP-Ti grade, different spec language — ASTM B381 calls it F-2; B363 fitting logic WPT2; UNS R50400; DIN 3.7035. Chemistry confirms, not the abbreviation.

Q2: Which class is in rotating stock?
A: Class 150/300 SORF+blind common; WN Class 300/600 on confirmed heat. Class 900+ forged to PO.

Q3: RF or RTJ?
A: RF default; RTJ groove machined to B16.5 for Class 600+ on request.

Q4: Forged or cast?
A: Closed-die forged (B381), CNC machined. No sand-cast for pressure service.

Q5: MTC real values?
A: EN 10204 3.1, measured interstitials + tensile, heat-to-ingot, QA-signed.

Q6: Pair with Gr2 stub end?
A: Yes — lap joint flange + Ti stub end is the standard cost-saving seawater combo.

Q7: Hot brine service?
A: Ambient–moderate T = Gr2. Above crevice threshold (~80°C depending on pH/deposit) → Gr7/Gr12 review.

Q8: Large bore 12–24"?
A: Forged to PO from project heat, B16.47 option, RT per PO. Not "shelf stock".

Q9: 3.2 possible?
A: Yes, TPI named at PO stage; cannot be back-built from 3.1 after shipment.

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

Request a Quote

Email: sales@[yourdomain].com

Send type + NPS×SCH + Class + face + qty. Reply in 24h: live heat status, EXW/FOB price, MTC type, dispatch window.

About: Baoji Titanium Valley Gr2 flange line — ASTM B381 F-2 (WPT2/R50400/3.7035), ASME B16.5, closed-die forged + CNC machined, pickled, face-protected, heat-traceable, EN 10204 3.1. Rotating small-bore stock + project-heat large bore. No cast-as-forged, no grade relabel, no cert downgrade. Lot confirmed before PI; tag = MTC = PL.