Tesco Steel & Engineering manufactures UNS C71500 copper nickel flanges — the 70/30 Cu-Ni alloy (CuNi30Mn1Fe, DIN 2.0882, EN CW354H), the high-nickel marine copper-nickel grade. With ~68% copper, 30% nickel and controlled iron and manganese, C71500 offers the highest seawater velocity tolerance, strength and elevated-temperature resistance of the copper-nickel grades, plus the family's natural antifouling behaviour and resistance to chloride stress-corrosion cracking. Available in weld neck, slip-on, blind, socket-weld, threaded and lap-joint types to ASME B16.5 / B16.47 and marine standards EEMUA 145 / DIN 86019. Class 150 to 2500, NPS 1/2″ to 24″, PN6 to PN400. ISO 9001:2015 certified. Made in India.
UNS C71500 (70/30) Copper Nickel Flanges
C71500 Weld Neck & Blind Flanges
Tesco Steel & Engineering manufactures C71500 copper nickel flanges in all types from weld neck to blind, Class 150 to 2500 — supplied with EN 10204 3.1 / 3.2 certification, PMI and third-party inspection on request. Explore the wider copper nickel flange range, UNS C70600 (90/10) copper nickel flanges, UNS C71640 copper nickel flanges, and the flange dimension charts.
| UNS C71500 (70/30) copper nickel flanges are available in the following specifications: | |
|---|---|
| Material Grade | UNS C71500 / 70/30 Cu-Ni / CuNi30Mn1Fe / DIN 2.0882 / EN CW354H |
| Alloy Type | Copper-nickel (~68% Cu, 30% Ni + Fe, Mn) — high-nickel marine grade |
| Size | 1/2″ NB to 24″ NB (DN 15 to DN 600); larger to ASME B16.47 |
| Class / Rating | 150#, 300#, 600#, 900#, 1500#, 2500# · 3000#, 6000#, 9000# (socket-weld / threaded) |
| Pressure Ratings | PN 6 – PN 400 (PN6, 10, 16, 25, 40, 64, 100, 160, 250, 320, 400) |
| Material Standards | ASTM B151 (rod), B171 (plate), B466 (pipe); EEMUA 145; DIN 86019 |
| Dimensional Standards | ASME B16.5, ASME B16.47 (Series A & B), MSS SP-44, DIN EN 1092-1 |
| Flange Types | Weld Neck (WNRF), Slip-On (SORF), Blind, Socket Weld (SWRF), Lap Joint, Threaded / Screwed, Plate, Long Weld Neck, Orifice |
| Flange Faces | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), Tongue & Groove (T&G) |
| Weld Filler | ERCuNi (AWS A5.7) |
| Testing | PMI, hydrostatic, UT, MT/PT per spec; EN 10204 3.1 / 3.2 |
70/30 copper nickel is a copper-rich alloy with 30% nickel plus deliberate iron and manganese additions. The higher nickel produces a more robust protective film than 90/10, while iron and manganese strengthen it against impingement and erosion-corrosion in fast-flowing seawater.
| Element | UNS C71500 (70/30 Cu-Ni) |
|---|---|
| Copper (Cu) | Balance (~66–68%) |
| Nickel (Ni) | 29.0 – 33.0% |
| Iron (Fe) | 0.40 – 1.0% |
| Manganese (Mn) | 0.50 – 1.5% |
| Zinc (Zn) | 1.0% max |
| Lead (Pb) | 0.05% max |
| Mechanical Property (annealed, typical) | UNS C71500 |
|---|---|
| Tensile Strength | 340 – 420 MPa (49–61 ksi) |
| Yield Strength 0.2% | 125 – 180 MPa (18–26 ksi) |
| Elongation | ~30% |
| Density | 8.95 g/cm³ |
| Max Service Temperature | ~350–400 °C |
| Max Seawater Velocity (pipe) | ~4.0–4.5 m/s |
| Standard | C71500 (70/30) Designation |
|---|---|
| UNS (USA) | C71500 |
| EN (Europe) | CW354H (CuNi30Mn1Fe) |
| DIN / Werkstoff | 2.0882 (CuNi30Mn1Fe) |
| BS (UK) | CN107 |
| ASTM material | B151 (rod), B171 (plate), B466 (pipe) |
| Common name | 70/30 Copper Nickel (Cu-Ni) |
C71500 Weld Neck (WNRF)
C71500 Slip-On (SORF)
C71500 Blind (BFF)
| Flange Type | Description & C71500-Specific Use |
|---|---|
| Weld Neck (WNRF) | Tapered hub butt-welded to pipe for high-integrity, high-velocity seawater lines; weld with ERCuNi filler, no PWHT. |
| Slip-On (SORF) | Fillet-welded over the pipe; common copper-nickel connection for naval and offshore seawater piping. |
| Blind (BFF) | Seals pipe ends and vessel nozzles in seawater, brine-heater and firewater systems. |
| Socket Weld (SWRF) | Small-bore (1/2″–2″) instrument and branch connections in seawater service. |
| Lap Joint (LJRF) | Used with a Cu-Ni stub end where frequent dismantling is needed; economises on alloy in the backing ring. |
| Threaded (TRFF) | Internal NPT/BSP threads for non-welded low-pressure seawater connections. |
| Long Weld Neck / Orifice / Plate | Nozzle, flow-metering and plate flanges in C71500 for marine, desalination and condenser duty. |
| Property | 70/30 (C71500) | 90/10 (C70600) | C71640 (66/30/2/2) |
|---|---|---|---|
| Nickel content | ~30% | ~10% | ~30% (Fe/Mn enhanced) |
| Seawater corrosion / antifouling | Excellent | Excellent | Excellent |
| Strength | Higher | Moderate | Higher |
| Max seawater velocity | ~4.0–4.5 m/s | ~3.0–3.5 m/s | Highest (sand-laden) |
| Elevated-temperature service | Better | Good | Better |
| Relative cost | Higher (more Ni) | Lowest | Higher |
| Best For | High-velocity / high-strength / hotter seawater | General seawater piping, shipboard | Sand-laden, high-velocity seawater (intakes) |
30% nickel gives a robust protective film — excellent general, pitting and crevice resistance plus high chloride-SCC resistance.
Handles seawater up to ~4.0–4.5 m/s without impingement attack — ideal for intakes, pumps and turbulent service.
Copper content inhibits barnacle, mussel and algae settlement — keeps pipe bores clear without coatings or biocides.
Stronger than 90/10 and better at elevated temperature — suited to brine heaters and high-temperature seawater stages.
| Industry | Typical Application |
|---|---|
| Naval & Marine | High-velocity seawater cooling, condenser, firewater and pump-connection flanges |
| Desalination | MSF brine heaters, high-temperature stages, high-velocity seawater intakes |
| Power Generation | Seawater-cooled condensers and feedwater heaters in coastal/marine plants |
| Offshore Platforms | Seawater and firewater systems, high-velocity intake and pump piping |
| Heat Exchangers | Tube-sheet and nozzle flanges in seawater-cooled and brine exchangers |
| Chemical & Process | Higher-strength / higher-temperature seawater and brine service |
Made from certified 70/30 copper-nickel with PMI verification of Ni, Fe and Mn — full chemistry on the MTC.
Manufactured to ASME B16.5 with EEMUA 145 / DIN 86019 compliance for naval, offshore and desalination work.
WNRF, SORF, blind, socket-weld, threaded, lap-joint, LWN, orifice and plate — in RF, FF, RTJ and T&G faces.
EN 10204 3.1 / 3.2 MTC, heat/lot traceability, hydrostatic and third-party inspection on request.
C71500 (70/30) flange prices track copper and the higher nickel content plus size, pressure class, flange type and quantity — it costs more than 90/10 but delivers higher velocity tolerance, strength and temperature capability. Tesco Steel & Engineering offers competitive ex-works pricing from Mumbai with full export documentation and material traceability. Click Ask for Quote or message us on WhatsApp at +91 92233 66922 with flange type, size (NB), pressure class, quantity and documentation requirements.
Q1. What is a UNS C71500 copper nickel flange?
A UNS C71500 copper nickel flange is a pipe flange made from 70/30 copper-nickel alloy (about 68% copper, 30% nickel, plus iron and manganese), also designated CuNi30Mn1Fe, DIN 2.0882 and EN CW354H. It is the higher-nickel copper-nickel grade, offering the highest seawater velocity tolerance, strength and elevated-temperature resistance of the Cu-Ni family, plus natural antifouling. Flanges are machined to ASME B16.5 / B16.47 dimensions and supplied to marine standards such as EEMUA 145 and DIN 86019.
Q2. What is the difference between 70/30 (C71500) and 90/10 (C70600) copper nickel?
Both copper-nickel alloys share excellent seawater corrosion and biofouling resistance. 90/10 (C70600) has 10% nickel and is the most economical grade for typical seawater velocities (up to ~3.0–3.5 m/s). 70/30 (C71500) has 30% nickel, giving higher strength, higher tolerance of seawater flow velocity (up to ~4.0–4.5 m/s), and better resistance at elevated temperature and in turbulent or hotter seawater. Choose 70/30 for higher-velocity, higher-strength or hotter duty; 90/10 for general lower-cost seawater piping.
Q3. What is the chemical composition of C71500 copper nickel?
UNS C71500 (70/30 Cu-Ni) composition: nickel 29.0–33.0%, iron 0.40–1.0%, manganese 0.50–1.5%, copper balance (~66–68%), with limits on zinc, lead and other residuals. The iron and manganese additions strengthen the protective surface film and improve resistance to impingement and erosion-corrosion in fast-flowing seawater.
Q4. Why is C71500 copper nickel used in high-velocity seawater service?
The higher 30% nickel content of C71500 produces a more robust, adherent protective film than 90/10, so it tolerates higher seawater flow velocities (about 4.0–4.5 m/s vs 3.0–3.5 m/s for 90/10) without impingement attack. It also has higher strength and better elevated-temperature performance, making it the preferred copper-nickel for brine heaters, high-velocity intakes, naval condensers and turbulent seawater service — while keeping copper-nickel's antifouling behaviour and chloride stress-corrosion resistance.
Q5. What standards apply to C71500 copper nickel flanges?
C71500 copper nickel flanges are made to ASME B16.5 / B16.47 dimensional standards in material to ASTM B151 (rod), ASTM B171 (plate) and ASTM B466 (pipe), and to marine fabrication standards EEMUA 145 and DIN 86019. Equivalents are CuNi30Mn1Fe, DIN/Werkstoff 2.0882, EN CW354H and BS CN107. Certification is supplied per EN 10204 3.1 / 3.2.
Q6. What are the mechanical properties of C71500 copper nickel?
Typical 70/30 copper nickel (C71500) properties in the annealed condition: tensile strength about 340–420 MPa, yield strength about 125–180 MPa, elongation about 30%, density 8.95 g/cm³. It is stronger than 90/10 (C70600) while remaining highly ductile, and is used where both seawater corrosion resistance and higher strength or velocity tolerance are required.
Q7. Can C71500 copper nickel flanges be welded?
Yes. C71500 is readily welded by GTAW (TIG) and GMAW using matching copper-nickel filler such as ERCuNi (AWS A5.7). No preheat or post-weld heat treatment is required. Joints should be clean and welded with controlled heat input; copper-nickel has higher thermal conductivity than steel, so technique differs slightly, but it is considered easy to weld for marine fabrication.
Q8. What is the maximum seawater flow velocity for 70/30 copper nickel?
70/30 copper nickel (C71500) tolerates a maximum continuous seawater velocity of about 4.0–4.5 m/s in pipework — higher than 90/10 (C70600) at about 3.0–3.5 m/s — before impingement attack of the protective film becomes a risk. This higher velocity capability, together with greater strength and elevated-temperature resistance, is the main reason to choose 70/30 over 90/10.
Q9. What industries use C71500 copper nickel flanges?
C71500 (70/30) copper nickel flanges are used in naval and marine seawater systems, high-velocity seawater intakes and pump connections, desalination plants (MSF brine heaters, high-temperature stages), power-station seawater condensers and feedwater heaters, offshore platform seawater and firewater systems, and chemical/marine heat exchangers — wherever the duty exceeds what 90/10 can handle in velocity, strength or temperature.
Q10. Are C71500 copper nickel flanges supplied with material test certificates?
Yes. Every C71500 copper nickel flange is supplied with EN 10204 3.1 (or 3.2) mill test certificates confirming chemistry, mechanical properties and heat/lot traceability, with PMI, hydrostatic testing and third-party inspection on request. Tesco Steel & Engineering is an ISO 9001:2015 certified manufacturer and exporter from Mumbai, India.