Gr1 Gr2 Gr5 Gr7 Titanium Pipe Fittings For Desalination Line ASME B16.9

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Проверено и поддерживается инженерной командой Shaanxi Qianyi Tuoda Technology Co., Ltd.

Titanium Pipe Fittings for Desalination Line | WPT2/WPT7/WPT12, ASTM B363 + ASME B16.9

Meta Description: Titanium pipe fittings for desalination lines from Baoji — ASTM B363 WPT2/WPT7/WPT12 butt weld elbows, tees, reducers, stub ends for SWRO/MSF/MED. Grade-by-duty selection against chloride, temperature and crevice risk. Pickled, bevel-capped, EN 10204 3.1.

Why Titanium in a Desalination Plant

Desalination is one of the most chloride-aggressive services on earth: raw seawater + high velocity + brine concentration + (in thermal plants) high temperature. Titanium survives because of a self-healing TiO₂ passive film — general corrosion rate in ambient seawater is effectively nil, and chloride stress-corrosion cracking is not a failure mode for CP titanium.[2,17](@ref)

But "use titanium" is not a one-grade answer. The right call is grade-by-circuit, not plant-wide Gr2 by default.

Desalination Circuit → Grade Map (Red/Yellow/Green)

Grade Quick Decision

• WPT2 (Gr2) — ambient seawater, permeate, intake, cooling. The default workhorse.[1,2](@ref)
• WPT7 (Gr2+Pd) — hot brine (>80°C), tight crevices, reducing-acid dosing. Use when CP Ti crevice risk is real.
• WPT12 (Ti-0.3Mo-0.8Ni) — hot chloride economy grade; crevice resistance above Gr2, lower cost than Gr7.
• WPT5 (Gr5) — only for load-bearing/high-strength hardware (risers, clamps), not for corrosion-only piping. Avoid over-specifying.

Fitting Types Supplied

• 90°/45° LR elbow (SR on PO), 180° return
• Equal / reducing tee
• Conc / ecc reducer (ecc for pump suction, no air pocket)
• Stub end Type A/B (pair with CS/SS backing flange = cost saver on large bore)
• Cap, custom piggable 3D/5D bend on request

All per ASTM B363 / ASME SB363 material, ASME B16.9 dimensions, MSS SP-43 for light-wall stub ends.

Wall / Schedule Rule (no over-spec)

Crevice & Welding Reality (must brief the site)

• CP Ti crevice attack possible in tight dead-legs above ~70–82°C — design out deposits, dead legs, low-flow stalls
• Weld: TIG, dual-side argon purge, trailing shield; accept silver/straw, reject blue/grey
• No steel brush, no carbon marker, no iron contamination
• Backing flange (CS/SS) OK on stub end — only titanium wets the fluid
• Galvanic: titanium is noble — isolate from less-noble metals with non-conductive sleeves/washers

Media Red Lines (titanium NOT the answer)

• Hydrofluoric acid / fluoride-bearing acidic streams — outside envelope
• Dry chlorine gas — exclude
• Hot concentrated reducing acids without Gr7 scope — use Gr7 or alternative alloy
• Red fuming nitric — exclude

Honest line: we flag the red line in RFQ review, not after hydrotest.

Inspection & Docs for Desalination Projects

• EN 10204 3.1: measured O/H/N/C + Fe (+Al/V for Gr5), heat-to-ingot
• Heat & lot traceability, bevel cap photo, crate-seal photo
• PT on seam-free body; RT/UT on welded fittings per PO
• 3.2 (SGS/BV/TÜV) PO-fronted for class-submission files
• CI/PL/COO/HS statement (WCO base 8108.90; destination sub-heading via broker)

RFQ Template (copy-paste, gets a real grade reply)

Circuit: intake / SWRO HP / permeate / MSF brine / MED / reject ___
Medium + Cl- ppm: ___
Temp: ___°C   Pressure: ___bar
Velocity / dead-leg concern: Y/N
Grade preference: Gr2 / Gr7 / Gr12 / let supplier recommend ___
Fitting: elbow 90LR / tee / reducer / stub end ___
NPS × SCH: ___ (DN ___)
Qty: ___ pcs
Cert: 3.1 / 3.2 (TPI ___)
Incoterm: EXW / FOB Shanghai / DAP ___

FAQ — Titanium Fittings for Desalination

Q1: Is Gr2 always enough for seawater?
A: For ambient aerated seawater — yes, standard workhorse. Above ~80°C in tight crevices/hot brine → Gr7 or Gr12.[8,14,17](@ref)

Q2: Gr7 vs Gr12 for hot brine?
A: Gr7 (Pd) highest crevice margin, cost premium. Gr12 (Mo-Ni) hot-chloride economy route, lower cost than Gr7 with strong crevice resistance.

Q3: Can titanium replace super duplex in SWRO HP?
A: Corrosion-wise yes; pressure wall still by code. Titanium wins on lifecycle, not on cheapest first cost vs F53/F55.

Q4: Stub end with CS backing flange — allowed?
A: Common cost move. Only titanium contacts fluid; isolate galvanically at bolt/face.

Q5: Welding on site?
A: Dual-side argon purge mandatory. We ship bevel-capped + clean; site WPS/qualification is the installer's scope.

Q6: Biofouling?
A: Titanium doesn't corrode under fouling; fouling still needs chlorination/velocity >2 m/s per plant CIP plan.

Q7: Large bore 12–24" brine header?
A: Welded/fabricated WPT2/WPT12, project heat, RT per PO. Not "shelf stock" — scheduled before PI.

Q8: HF in cleaning chemical?
A: Flag it. Titanium + fluoride acid = red line; we re-route material, not bluff.

Q9: MTC real measured values?
A: EN 10204 3.1, heat-to-ingot, interstitials measured.

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

Request a Quote

Email: sales@[yourdomain].com

Send circuit + T/Cl⁻/pressure + grade intent. Reply in 24h: grade recommendation (not sales-default Gr2), heat status, EXW/FOB price, MTC type, dispatch window.

About: Baoji Titanium Valley desalination line — ASTM B363 WPT2/WPT7/WPT12 butt weld fittings, ASME B16.9, pickled, bevel-capped, heat-traceable, EN 10204 3.1. Grade chosen by circuit duty (ambient seawater / hot brine / reducing dose), not by catalogue habit. No phantom "all-titanium plant" promise; red lines (HF, dry Cl₂) flagged before PI. Lot confirmed, docs matched, auditable.