Pure Nickel Tube For Caustic Soda Plant

Specification	We stock common OD and wall thickness sizes, support cut-length processing, offer clean packaging and complete export documents for chlor-alkali plant EPC contractors and end users.
Applicable Standard	Manufactured from Nickel 200 UNS N02200 and tested under ASTM B161 norms, these tubes pass hydrostatic inspection and PMI identification, with traceable certification for alkali plant audit checks.
Material Condition	Unlike stainless steel and titanium, pure nickel avoids caustic embrittlement and stress corrosion cracking in high-temperature lye environments, sustaining stable performance under continuous alkalin
Inspection & Packaging	We stock common OD and wall thickness sizes, support cut-length processing, offer clean packaging and complete export documents for chlor-alkali plant EPC contractors and end users.
Reference Price	$50.00 – $60.00

Product Description: Pure Nickel 200 (UNS N02200) tube for caustic soda plant, ASTM B161 standard. Resists hot concentrated sodium hydroxide and caustic embrittlement, ideal for chlor-alkali electrolysis and evaporation l

Product Overview

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

Pure Nickel Tube for Caustic Soda Plant | Nickel 200 / 201 (N02200/N02201), ASTM B161/B163, MTC 3.1

Pure Nickel Tube for Caustic Soda Plant

Nickel 200 / N02200Nickel 201 / N02201ASTM B161 / B163EN 10204 3.1

SEO Title: Pure Nickel Tube for Caustic Soda Plant | Nickel 200/201, ASTM B161/B163, MTC 3.1
URL Slug: pure-nickel-tube-for-caustic-soda-plant
Meta Description: Pure nickel tube for caustic soda plants — Nickel 200 (N02200) for service ≤315°C, Nickel 201 (N02201) for high-temp evaporators. ASTM B161 seamless & B163 heat-exchanger tube, annealed, PMI tested, EN 10204 3.1. Caustic-SCC resistant.

1. One Sentence — Why Caustic Soda Plants Pick Pure Nickel

The hotter and more concentrated the alkali, the more a plant needs pure nickel. That is the whole rule. Where austenitic stainless steels crack under hot concentrated caustic soda, pure nickel stays passive and stable.

Nickel 200 / 201 contains at least 99.0% nickel. Its self-healing oxide film handles sodium hydroxide and potassium hydroxide across the full concentration range at moderate temperatures — and unlike 304 or 316L, it does not fall apart in caustic stress-corrosion cracking.

The plain-language version: alkaline lines that eat stainless steels alive are exactly where pure nickel earns its place. It is not "stronger steel" — it is a different material class that simply does not react with caustic the same way.

2. Nickel 200 or Nickel 201? One Number Decides

Both grades share the same Ni≥99.0% chemistry. The split is carbon content, and carbon decides the service ceiling.

Item	Nickel 200 (N02200)	Nickel 201 (N02201)
Carbon, max	0.15%	0.02%
Service ceiling	≤315°C (600°F)	Up to ~650°C
Best fit	Standard caustic soda lines, ambient–moderate T	Hot-concentrated alkali, evaporators, high-T duty
Why the limit	Above 315°C, carbon precipitates as graphite at grain boundaries	Low carbon prevents graphite precipitation

315°C is the watershed. Above it, carbon in Nickel 200 comes out of solution and forms graphite at the grain boundaries. Ductility collapses, and the tube can fail with no visible warning. Sending 200 into a high-temperature evaporator is not a cost-saving move — it is a failure waiting to happen. That is why service >315°C always goes to 201.

3. Standards — Get This Right on the PO

ASTM B161 / ASME SB-161 — cold-worked seamless nickel pipe and tube (N02200 / N02201)
ASTM B163 / ASME SB-163 — seamless nickel and nickel-alloy condenser and heat-exchanger tubes
ASTM B725 — welded nickel pipe (do not label this as seamless B161)

B161 and B163 are not interchangeable — one is general seamless pipe/tube, the other is condenser and heat-exchanger tubing. State the correct standard on the RFQ.

4. Where Pure Nickel Tube Sits in a Caustic Soda Plant

Falling-film evaporator tubes / forced-circulation evaporator tubes
NaOH transfer mains and finished-product cooling lines
Electrolyzer cathode-side alkali lines
Concentrated-alkali storage-tank heating coils
High-purity caustic soda lines (low iron pick-up)
Condensers and reboilers handling alkaline service

5. Why It Works — The Engineering Reasons

Property	What it means in service
Ni ≥99.0%	Stable passive film in caustic, all concentrations, moderate temperatures
Caustic-SCC resistance	No alkali-induced stress-corrosion cracking like 300-series stainless
Thermal conductivity ~70 W/m·K	3–5× austenitic stainless — evaporator tubes run efficiently
Density 8.89 g/cm³	Heavier than titanium, lighter than copper-alloy alternatives in same duty
Non-contaminating	Suitable for food-grade and high-purity alkali handling

6. Mechanical Properties (annealed, typical)

Property	Value
Tensile strength, min	≥380 MPa (55 ksi)
Yield strength (0.2%), min	≥105 MPa (15 ksi)
Elongation, min	≥35–40%
Melting range	~1435–1446°C

7. Typical Stock Window

Parameter	Range
Outside diameter	6–219 mm (1/2"–8"); fractional sizes on request
Wall / Schedule	SCH 5S, 10S, 40S, 80S, STD, XS, up to SCH 160 (confirmation required)
Length	Single / double random, or cut-to-length (commonly 3000–6000 mm)
Condition	Annealed, bright annealed, pickled; stress-relieved by agreement
Ends	Plain end / beveled end / threaded on request

Live stock moves daily. Send OD × wall (or NPS × SCH) plus quantity for a same-day availability answer.

8. QC Before Dispatch

Heat certificate to EN 10204 3.1 — chemistry and tensile from parent heat
PMI / OES grade verification — N02200 ≠ N02201 ≠ alloy 625, confirmed not guessed
Hydrostatic test or electric NDT (per PO / general requirements)
Flattening and flare / expansion tests per applicable specification
OD, wall, length and end-face inspection
Traceability: heat number → tube tag → MTC cross-linked
EN 10204 3.2 (SGS / BV / TÜV) with TPI named at PO stage — never back-built

9. The Honest Boundaries

Where pure nickel is the wrong call:

Strong oxidizers — nitric acid, wet chlorine excursion, hypochlorite-rich streams. Pure nickel is for reducing/alkaline duty, not oxidizing chloride.
Stagnant seawater with biofouling — localized attack risk; design review required.
Above 315°C on Nickel 200 — upgrade to 201 before ordering.
High chlorate in alkali — can accelerate pitting; impurity control matters, and "pure nickel" is not a blanket guarantee.

Welding uses ERNi-1 filler. Keep sulphur and lead away from the joint, and never drag a steel wire brush across nickel — cross-contamination ruins the surface.

10. RFQ Template — Copy, Paste, Send

Standard:        ASTM B161 (pipe/tube) / B163 (exchanger tube) ___
Grade:           N02200 (Nickel 200) / N02201 (Nickel 201) ___
OD:              ___ mm  (or NPS ___)
Wall:            ___ mm  (or SCH ___)
Length:          random / fixed ___ mm
Condition:       annealed / bright annealed / pickled ___
Ends:            plain / bevel / threaded ___
Service:         NaOH/KOH concentration ___%   Temp ___°C
Test:            hydrostatic / NDT / both ___
Cert:            3.1 / 3.2 (TPI ___)
Quantity:        ___ m / ___ pcs
Incoterm:        EXW Baoji / FOB Shanghai / DAP / DDP ___

11. FAQ — Pure Nickel Tube for Caustic Soda Service

Q1: Why pure nickel instead of 316L for caustic soda?
A: Because 316L is vulnerable to caustic stress-corrosion cracking as concentration and temperature rise. Pure nickel is not. That is the single reason chlor-alkali plants standardize on it.

Q2: 200 or 201 — how do I choose?
A: Service ≤315°C → Nickel 200. Service >315°C or any hot-concentrated alkali evaporator → Nickel 201. Carbon content is the deciding line.

Q3: Is graphite precipitation reversible?
A: No. Once carbon has precipitated at grain boundaries above the temperature limit, ductility does not come back. Prevention is the only option, which is why the grade decision is made before the PO.

Q4: Can pure nickel handle nitric acid?
A: Not as a default. Nitric is oxidizing acid — pure nickel belongs in reducing and alkaline duty. Send the exact medium and temperature for a proper alloy review.

Q5: What standard for heat-exchanger tubes?
A: ASTM B163 (SB-163). B161 covers general seamless pipe and tube, not condenser and exchanger tubing.

Q6: Is there stock, or is this all mill lead time?
A: Common sizes rotate in stock; heavy wall and unusual NPS are quoted to mill lead. Send dimensions and quantity for a fast availability check.

Q7: MTC with a small quantity?
A: EN 10204 3.1 with every lot. 3.2 is available when a TPI is named at the PO stage.

Q8: Does pure nickel contaminate high-purity caustic?
A: Nickel pick-up is negligible in caustic service, which is why it is used for high-purity alkali. Surface finish and cleaning state are agreed per application.

Q9: HS code for nickel tube?
A: Base 7506.20 for nickel tubes/pipes; the destination sub-heading must be confirmed with the buyer's broker.

Q10: What is the single biggest mistake buyers make?
A: Quoting 200 for a line that runs above 315°C to save cost. The right answer is 201 — and a supplier who quotes 200 without asking the temperature is not doing the job properly.

12. Request a Quote

Email: sales@[yourdomain].com

Send OD × wall (or NPS × SCH) + grade + NaOH concentration + operating temperature + quantity. Stock answer within hours; dispatch window on heat confirmation.

About: Baoji nickel-tube desk — pure nickel tubes for caustic soda plants, ASTM B161 / SB-161 and ASTM B163 / SB-163, Nickel 200 (UNS N02200) for service to 315°C and Nickel 201 (UNS N02201) for high-temperature caustic evaporators. Annealed, cold-worked seamless, PMI verified, hydrostatic or NDT tested, EN 10204 3.1 with every lot and 3.2 available with PO-fronted TPI. No welded-passed-as-seamless, no grade mix, no 200 quoted above 315°C without flagging 201, no carbon confusion between 200 and 201. Heat number = tube tag = MTC.

pure nickel tube caustic soda plant