ASME SB163 UNS N08825 (Alloy 825 / Incoloy 825) Seamless Heat Exchanger Tubing

ASME SB163 UNS N08825 (Alloy 825 / Incoloy 825) Seamless Heat Exchanger Tubing

ASME SB163 UNS N08825 seamless tube, also widely known as Alloy 825 / Incoloy 825 seamless tubing, is a titanium-stabilized austenitic nickel-iron-chromium alloy pipe manufactured strictly in accordance with ASME SB163 specification. This standard governs seamless nickel alloy tubes dedicated to condenser and heat exchanger service, delivering precise dimensional control and consistent metallurgical quality for heat transfer equipment.

Alloy 825 features balanced chemical composition with intentional additions of molybdenum, copper and titanium. The high nickel matrix provides strong resistance against chloride-induced stress corrosion cracking. Molybdenum effectively prevents pitting and crevice corrosion, while titanium stabilizes the microstructure to avoid intergranular corrosion after welding or long-term thermal exposure. Unlike regular stainless steel, UNS N08825 performs reliably in both oxidizing and reducing corrosive media, standing out in sulfuric acid, phosphoric acid, brine, seawater and sour gas environments.

Produced via fully seamless cold drawing & pilger rolling processes, our SB163 N08825 tubing eliminates hidden risks from welded seams. We supply tubes in bright annealed or pickled finish with tight OD & wall thickness tolerances required by ASME SB163. Each batch undergoes strict inspections including chemical composition analysis, tensile & hardness testing, hydrostatic pressure test, eddy current non-destructive testing and PMI verification. Full test certificates meeting EN 10204 3.1 / 3.2 can be provided upon request.

Material: ASME SB163 UNS N08825 (Alloy 825 / Incoloy 825)

(1). Chemical Composition (Weight %, ASME SB163 Standard Limits)

Notes: Balance is Iron. Values conform to ASME SB163 specification for seamless tubes.

(2). Mechanical Properties (Solution Annealed Condition, Room Temperature ASME SB163)

Equivalent Materials:

UNS N08825 is commercially known as Incoloy 825. Its international equivalent grades include W.Nr.2.4858 (NiCr21Mo), JIS NCF825, BS NA16, GB NS1402 and GOST XH38BT. ASME SB163 is the dedicated specification for seamless heat exchanger tubing of UNS N08825, while ASME SB423 covers general seamless pipe of the same alloy chemistry. All equivalent grades feature matching chemical composition and corrosion resistance performance, but formal standard approval should be confirmed before substitution in engineering projects.

Core Advantages

✅ Complies fully with ASME SB163 for heat exchanger & condenser tubular service

✅ Excellent resistance to SCC, pitting and crevice corrosion in chloride-containing fluids

✅ Superior performance against sulfuric, phosphoric and various organic acids

✅ Stable mechanical properties from cryogenic temperature up to 540°C

✅ Titanium stabilization prevents sensitization during fabrication and operation

✅ Seamless structure ensures high pressure integrity and uniform heat transfer

✅ Custom OD, wall thickness, straight lengths and U-bent tubes available

Applications of ASME SB163 UNS N08825 Seamless Tube

Main Description Paragraph

ASME SB163 UNS N08825 seamless tube is specially designed for heat exchanger and condenser service as defined by the ASME SB163 specification. Thanks to outstanding resistance to stress corrosion cracking, pitting and crevice corrosion in acidic, saline and chloride-containing media, this seamless nickel alloy tubing is widely adopted for critical corrosion-resistant heat transfer equipment across the chemical, petrochemical, oil & gas, marine and environmental protection industries.

Classified Application List

1. Oil & Gas Industry

Sour service heat exchangers and cooling tubes

Offshore seawater cooling systems

Downhole chemical injection pipelines

Onshore processing plant condensers

2. Chemical & Petrochemical Industry

Heat exchangers, evaporators and condensers

Sulfuric acid and phosphoric acid production equipment

Organic acid processing facilities

Pickling circuit tubing

3. Marine & Desalination

Seawater heat exchange pipelines

Desalination plant heat transfer tubes

Marine platform cooling equipment

4. Environmental Protection

Flue gas desulfurization (FGD) heat exchangers

Waste gas and wastewater treatment facilities

5. Power & Other Industrial Fields

Power plant auxiliary cooling systems

Pharmaceutical processing heat exchange equipment

Food industry corrosion-resistant heat transfer tubes