LEADING COPPER NICKEL 90/10 & 70/30 COLLAR MANUFACTURER & EXPORTER — ISO 9001:2015 CERTIFIED
Manufacturer, Exporter & Supplier of Copper-Nickel 90/10 & 70/30 Composite Flange — ASME B16.5 · ASME B16.9 · MSS SP-43
Manufacturer, Supplier & Exporter of Copper-Nickel Composite Flanges — a complete, ready-to-install Van Stone flange assembly combining a CuNi 90/10 (UNS C70600) or CuNi 70/30 (UNS C71500) stub end with a loose backing flange, conforming to ASME B16.5, ASME B16.9, MSS SP-43, DIN, NAVSEA T9074 and NORSOK standards.
A Copper Nickel Composite Flange — also known as a Van Stone Flange Assembly or Copper Nickel Rotating Flange Collar — is a complete, ready-to-bolt flanged fitting supplied as a pre-assembled unit: a CuNi 90/10 or CuNi 70/30 stub end (the wetted, corrosion-resistant part welded to the pipe) fitted together with a loose backing flange that rotates freely for bolt-hole alignment. Unlike a standalone Welding Neck Collar or Stub End Collar, which is supplied as a single component for the fabricator to assemble on site, the Composite Flange arrives from Sunflex Metalloy as a complete, pre-fitted assembly — saving installation time and eliminating on-site fit-up risk.
The key commercial advantage of the Composite Flange is material economy: only the wetted stub end needs to be manufactured in expensive Copper-Nickel alloy, while the structural backing flange — which never contacts the seawater or process fluid — can be supplied in carbon steel, stainless steel, or CuNi depending on the specifier's requirement. This delivers full corrosion protection at the wetted face at a fraction of the cost of an all-CuNi solid flange, which is why Composite/Van Stone Flange assemblies are the standard specification on the majority of marine, offshore and shipbuilding CuNi piping projects worldwide.
As a specialist Copper Nickel Collar and Stub End Manufacturer, Supplier and Exporter, Sunflex Metalloy manufactures the stub end, machines the backing flange bore and face, and pre-assembles the complete Composite Flange in-house to ASME B16.5 flange dimensions and ASME B16.9 / MSS SP-43 stub end proportions — with every assembly backed by an EN 10204 3.1 Mill Test Certificate covering the CuNi stub end material, dimensional inspection and hydrostatic test records.
Wetted Part Material: CuNi 90/10 / CuNi 70/30
UNS: C70600 / C71500 / C70620 / C71640
Backing Flange Material: Carbon Steel / Stainless Steel / CuNi
DIN: CuNi10Fe1Mn (2.0872) / CuNi30Mn1Fe (2.0882)
Standards: ASME B16.5 · ASME B16.9 · MSS SP-43
Size: ½" (DN15) to 48" (DN1200) NB & Custom
Face Type: Flat Face (FF) / Raised Face (RF)
Pressure: Class 150 to Class 2500
MTC: EN 10204 3.1 supplied
Request a Quote| Element | CuNi 90/10 — UNS C70600 (CW352H / CuNi10Fe1Mn) | CuNi 70/30 — UNS C71500 (CW354H / CuNi30Mn1Fe) |
|---|---|---|
| Copper (Cu) | Remainder (min 86.5%) | Remainder (min 65.0%) |
| Nickel + Cobalt (Ni + Co) | 9.0 – 11.0% | 29.0 – 33.0% |
| Iron (Fe) | 1.0 – 1.8% | 0.40 – 1.0% |
| Manganese (Mn) | 0.5 – 1.2% | 1.0% max |
| Lead (Pb) | 0.05% max | 0.02% max |
| Carbon (C) | 0.05% max | 0.05% max |
| Sulphur (S) | 0.02% max | 0.02% max |
| Zinc (Zn) | 1.0% max | 0.50% max |
* Composition applies to the CuNi stub end (wetted component). The backing flange, where supplied in carbon steel or stainless steel, is certified separately to its own material standard (e.g. ASTM A105, ASTM A182 F304/F316).
| Property | CuNi 90/10 (UNS C70600) | CuNi 70/30 (UNS C71500) | Test Standard |
|---|---|---|---|
| Tensile Strength (UTS) | 275 MPa min (40 ksi) | 380 MPa min (55 ksi) | ASTM E8 / ISO 6892-1 |
| Yield Strength (0.2% PS) | 105 MPa min (15 ksi) | 170 MPa min (25 ksi) | ASTM E8 / ISO 6892-1 |
| Elongation (in 50 mm) | 30% min | 30% min | ASTM E8 / ISO 6892-1 |
| Hardness | 45 HRB max | 65 HRB max | ASTM E18 / ISO 6508 |
| Density | 8.94 g/cm³ | 8.95 g/cm³ | – |
| Modulus of Elasticity | 135 GPa | 150 GPa | – |
| Thermal Conductivity | 40 W/m·K | 29 W/m·K | – |
| Melting Point (Approx.) | 1100°C | 1170°C | – |
| NPS (inch) | DN | Stub End Hub O.D. (mm) | Flange Face O.D. (mm) | Overall Length (mm) | Min. Wall (mm) |
|---|---|---|---|---|---|
| 1/2" | DN15 | 21.3 | 90 | 38 | 1.65 |
| 3/4" | DN20 | 26.7 | 100 | 38 | 1.65 |
| 1" | DN25 | 33.4 | 110 | 51 | 1.65 |
| 1 1/2" | DN40 | 48.3 | 135 | 57 | 1.65 |
| 2" | DN50 | 60.3 | 150 | 64 | 1.65 |
| 3" | DN80 | 88.9 | 190 | 79 | 3.05 |
| 4" | DN100 | 114.3 | 230 | 90 | 3.05 |
| 6" | DN150 | 168.3 | 280 | 108 | 3.4 |
| 8" | DN200 | 219.1 | 345 | 121 | 3.76 |
| 10" | DN250 | 273.0 | 405 | 133 | 4.19 |
| 12" | DN300 | 323.9 | 485 | 146 | 4.57 |
| 16" | DN400 | 406.4 | 580 | 165 | 4.78 |
| 20" | DN500 | 508.0 | 715 | 187 | 5.54 |
| 24" | DN600 | 609.6 | 840 | 210 | 6.35 |
* Dimensions are indicative and manufactured to the purchaser's drawing / applicable standard (ASME B16.5, ASME B16.9, MSS SP-43). Custom sizes, special wall thicknesses, backing flange materials and non-standard face preparations manufactured on request. Full certified drawings issued on order confirmation.
Prime-grade CuNi 90/10 / CuNi 70/30 billet sourced from certified mills for the stub end; carbon steel or stainless steel plate/forging sourced for the backing flange. Incoming chemical composition verified by PMI (XRF) and spectrochemical analysis.
CuNi stub end forged or machined from seamless pipe to ASME B16.9 / MSS SP-43 proportions, with precision-machined lap face and radius for correct seating against the backing flange.
Backing flange bored and faced to ASME B16.5 dimensions, then fitted over the stub end lap and checked for free rotation and correct bolt-hole alignment — delivering a complete, ready-to-install composite assembly.
100% dimensional check, hydrostatic pressure test, spectrochemical chemical analysis of the CuNi stub end, mechanical testing, visual inspection and PMI. EN 10204 3.1 MTC issued for the assembly.
A Copper Nickel Composite Flange is a complete, pre-assembled Van Stone flange unit consisting of a CuNi stub end (the wetted, corrosion-resistant surface welded to the pipe) fitted with a loose backing flange that clamps it in place and rotates freely for bolt-hole alignment. It arrives ready to bolt into the piping system, rather than as a separate collar the fabricator must assemble on site.
A Stub End Collar or Welding Neck Collar is supplied as a single CuNi component only — the fabricator sources and fits a separate loose backing flange on site. A Composite Flange is the complete pre-assembled unit, with the CuNi stub end and backing flange already fitted together and inspected for correct rotation and bolt-hole alignment before dispatch, saving site labour and eliminating fit-up risk.
The backing flange is most commonly supplied in carbon steel (e.g. ASTM A105) or stainless steel (e.g. ASTM A182 F304/F316) for maximum cost savings, since it never contacts the corrosive seawater or process fluid. A full CuNi backing flange is also available where specified for uniformity or additional corrosion margin.
Sunflex Metalloy manufactures Composite Flange assemblies with the stub end to ASME B16.9 (long pattern) or MSS SP-43 (short pattern), and the backing flange to ASME B16.5 dimensions, with DIN Van Stone Collar, EEMUA 145, NAVSEA T9074, DEF STAN and NORSOK compliance available on request.
Share your size, grade (CuNi 90/10 / CuNi 70/30), backing flange material, applicable standard and quantity for a competitive quotation with EN 10204 3.1 MTC.
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