Copper Nickel Socket Weld Flange
HC Aluminum manufactures and supplies copper nickel socket weld flanges for marine, seawater, offshore and industrial piping systems. Our socket weld flanges are available in C70600 CuNi 90/10 and C71500 CuNi 70/30, with dimensions manufactured to ASME B16.5 Class 150 and Class 300 requirements.
A socket weld flange has a recessed socket that receives the pipe end. An external fillet weld connects the pipe to the flange hub, while bolts and a gasket form the removable connection between mating flanges. This arrangement is commonly considered for small-bore piping where copper nickel’s resistance to seawater corrosion is required.
- Material
- C70600 CuNi 90/10 · C71500 CuNi 70/30
- Standard
- ASME B16.5
- Facing
- Flat Face · Raised Face
- Production
- Standard · Drawing-Based Production
What Is a Copper Nickel Socket Weld Flange?
A copper nickel socket weld flange is a flanged pipe connection designed with a recessed socket into which the pipe is inserted before welding.
Unlike a slip-on arrangement, the pipe is positioned inside the socket bore and seats against the internal shoulder. The connection is then secured with a fillet weld at the pipe and flange junction.
The flange face is bolted to a matching flange with the specified gasket to complete the piping joint.
This compact configuration is commonly considered for smaller-bore copper nickel piping where accurate pipe alignment, a permanent welded connection and limited installation space are important.
Copper Nickel Socket Weld Flange Specifications
| Item | Specification |
| Product type | Copper nickel socket weld flange / CuNi SW flange |
| Manufacturer and supplier | HC Aluminum |
| Alloy grades | UNS C70600, copper nickel 90/10; UNS C71500, copper nickel 70/30 |
| Dimensional reference | ASME B16.5 |
| Pressure classes | Class 150 and Class 300 |
| Size | NPS 1/2 to 24, as applicable to the selected configuration |
| Flange facing | Flat face (FF) or raised face (RF), subject to mating-flange and project requirements |
| Size selection | Confirmed by nominal pipe size, actual pipe outside diameter, wall thickness and applicable socket weld dimensional provisions |
| Pipe connection | Socket insertion with an external fillet weld |
| Flanged connection | Bolted joint with a suitable gasket |
| Socket and bore | Matched to the specified pipe and approved drawing |
| Other standards | EN 1092-3 or project-specific requirements can be reviewed separately for dimensional and material compatibility |
C70600 and C71500 Copper Nickel Socket Weld Flanges
HC Aluminum supplies socket weld flanges in two commonly specified copper nickel alloy grades. The final grade should be selected according to the applicable material standard, service conditions, piping design and purchase specification.
CuNi 90/10
UNS C70600, commonly known as 90/10 copper nickel, is widely used in seawater, marine and cooling-water piping. It provides a practical combination of seawater corrosion resistance, fabrication performance and long-term service characteristics.
- C70600 copper nickel alloy
- CuNi 90/10
- Marine and seawater piping
- Cooling-water applications
- Shipbuilding and desalination projects
CuNi 70/30
UNS C71500, commonly known as 70/30 copper nickel, is specified for projects requiring the properties of the higher-nickel copper nickel alloy. It is used in selected marine, offshore and seawater applications according to the project specification.
- C71500 copper nickel alloy
- CuNi 70/30
- Marine and offshore piping
- Higher-flow seawater applications
- Demanding marine service conditions
C70600 and C71500 should not be treated as automatic substitutes. Material selection should be based on the governing material standard, seawater or process conditions, pressure and temperature requirements, piping design and project specification.
Copper Nickel Socket Weld Flange Dimensions
ASME B16.5 CL 150 Copper Nickel SW Flange Dimensions
| specification | d1 | A | H | C | X | R | B1 | B2 | Y | G | N-Od2 | Weight |
| inch | mm | mm | mm | mm | mm | mm | mm | mm | mm | mm | kg | |
| 1/2" | 21.3 | 88.9 | 15.9 | 11.2 | 30.2 | 34.9 | 22.4 | 15.7 | 9.5 | 60.3 | 4-15.9 | 0.80 |
| 3/4" | 26.7 | 98.4 | 15.9 | 12.7 | 38.1 | 42.9 | 27.7 | 20.8 | 11.1 | 69.8 | 4-15.9 | 1.10 |
| 1" | 33.4 | 107.9 | 17.5 | 14.3 | 49.2 | 50.8 | 34.5 | 26.7 | 12.7 | 79.4 | 4-15.9 | 1.20 |
| 11/4" | 42.2 | 117.5 | 20.6 | 15.9 | 58.7 | 63.5 | 43.2 | 35.1 | 14.3 | 88.9 | 4-15.9 | 1.50 |
| 11/2" | 48.3 | 127 | 22.2 | 17.5 | 65.1 | 73 | 49.5 | 40.9 | 15.9 | 98.4 | 4-15.9 | 1.60 |
| 2" | 60.3 | 152.4 | 25.4 | 19.1 | 77.8 | 92.1 | 61.9 | 52.6 | 17.5 | 120.6 | 4-19 | 2.70 |
| 21/2" | 73 | 177.8 | 28.6 | 22.2 | 90.5 | 104.8 | 74.7 | 62.7 | 19 | 139.7 | 4-19 | 4.10 |
| 3" | 88.9 | 190.5 | 30.2 | 23.8 | 107.9 | 127 | 90.7 | 78 | 20.6 | 152.4 | 4-19 | 5.10 |
| 4" | 114.3 | 228.6 | 33.3 | 23.8 | 134.9 | 157.2 | 116.1 | 102.4 | 23.8 | 190.5 | 8-19 | 7.00 |
ASME B16.5 CL 300 Copper Nickel SW Flange Dimensions
| specification | d1 | A | H | C | X | R | B1 | B2 | Y | G | N-Od2 | Weight |
| inch | mm | mm | mm | mm | mm | mm | mm | mm | mm | mm | kg | |
| 1/2" | 21.3 | 95.2 | 22.2 | 14.3 | 38.1 | 34.9 | 22.4 | 15.7 | 9.5 | 66.7 | 4-15.9 | 0.90 |
| 3/4" | 26.7 | 117.5 | 25.4 | 15.9 | 47.6 | 42.9 | 27.7 | 20.8 | 11.1 | 82.5 | 4-19 | 1.40 |
| 1" | 33.4 | 123.8 | 27 | 17.5 | 54 | 50.8 | 34.5 | 26.7 | 12.7 | 88.9 | 4-19 | 1.70 |
| 11/4" | 42.2 | 133.3 | 27 | 19 | 63.5 | 63.5 | 43.2 | 35.1 | 14.3 | 98.4 | 4-19 | 2.00 |
| 11/2" | 48.3 | 155.6 | 30.2 | 20.6 | 69.8 | 73 | 49.5 | 40.9 | 15.9 | 114.3 | 4-22.2 | 3.00 |
| 2" | 60.3 | 165.1 | 33.3 | 22.2 | 84.1 | 92.1 | 61.9 | 52.6 | 17.5 | 127 | 8-19 | 3.40 |
| 21/2" | 73 | 190.5 | 38.1 | 25.4 | 100 | 104.8 | 74.7 | 62.7 | 19 | 149.2 | 8-22.2 | 5.10 |
| 3" | 88.9 | 209.5 | 42.9 | 28.6 | 117.5 | 127 | 90.7 | 78 | 20.6 | 168.3 | 8-22.2 | 6.80 |
| 4" | 114.3 | 254 | 47.6 | 31.8 | 146.1 | 157.2 | 116.1 | 102.4 | 23.8 | 200 | 8-22.2 | 11.30 |
Applications of Copper Nickel Socket Weld Flanges
Marine and Shipbuilding Piping
Socket weld copper nickel flanges can be used in compact sections of shipboard seawater and utility piping, including cooling-water, ballast and firefighting systems where the applicable design calls for this connection type.
Offshore Piping
For offshore installations, C70600 or C71500 socket weld flanges may be specified for selected seawater and utility piping sections where copper nickel corrosion resistance is required.
Desalination and Water Treatment
Copper nickel flange components are also used in selected seawater, brine and treated-water piping systems. Final material and pressure-class selection should follow the project specification and operating conditions.
Socket weld connections contain an internal crevice. They may not be the preferred choice where the specification restricts socket welds, where fatigue loading is significant, or where the service requires a full-penetration butt-welded connection.For these applications, review our copper nickel weld neck flanges alongside the project piping requirements.
Why Use Copper Nickel for Marine Piping?
Copper nickel alloys are widely used in marine and seawater piping because their performance is suited to corrosion-sensitive service. Final suitability still depends on water chemistry, velocity, temperature, flow conditions and the complete piping design.
Seawater Corrosion Resistance
Copper nickel alloys are widely selected for seawater-related piping because of their corrosion resistance under suitable service conditions. They are used in marine and seawater systems where long-term material stability is important.
Resistance to Erosion-Corrosion
Copper nickel alloys can provide useful resistance to erosion-corrosion in flowing seawater systems when the alloy, flow conditions and installation practices are properly matched.
Marine Compatibility
C70600 and C71500 are established copper nickel grades for marine-related piping applications, including seawater cooling, shipbuilding and offshore service.
Fabrication and Welding
Proper pipe fit-up, welding procedure, cleanliness, joint design and post-weld practices remain important to the final performance of a copper nickel piping assembly.
Quality Control and Inspection of Copper Nickel Socket Weld Flanges
Each copper nickel socket weld flange can be checked for material, dimensions, bolt hole accuracy, flange thickness, sealing face condition, marking and overall appearance before shipment. Inspection requirements can be aligned with the applicable flange specification, material grade and project requirements.
Common Inspection Items
- Material verification: alloy grade, heat or lot identification and applicable material documentation
- Dimensional inspection: flange OD, bore, hub and overall dimensions against the specified standard or drawing
- Flange thickness inspection: check flange thickness at defined measuring points to confirm dimensional compliance
- Bolt hole inspection: bolt hole diameter, quantity, pitch circle diameter and hole alignment
- Sealing face inspection: sealing surface finish, flatness and visible surface condition
- Socket inspection: socket diameter, depth and related dimensions where specified
- Visual inspection: surface condition, machining quality, edge condition and visible defects
- Marking inspection: material grade, size, pressure class and other required identification marks
- Packing inspection: protection of machined surfaces, flange faces and identification during export shipment
- Project-specific testing: additional inspection or testing when required by the applicable specification, drawing or purchase order
Copper Nickel Socket Weld Flange and Pipe Compatibility
Proper flange-to-pipe matching is essential for a reliable copper nickel piping connection. For socket weld flange applications, the flange dimensions should be checked against the pipe NPS, outside diameter, wall thickness and applicable piping standard. The socket and bore must also be suitable for the actual pipe size and installation arrangement.
HC can supply matching copper nickel pipe in C70600 CuNi 90/10 and C71500 CuNi 70/30, allowing the pipe and flange materials to be specified as part of the same piping package.
For 90/10 copper nickel piping, see our C70600 / 90/10 copper nickel pipe for available sizes, grades and supply details.
For 70/30 copper nickel piping, see our C71500 / 70/30 copper nickel pipe for material and dimensional information.
For projects using fabricated pipe sections, our welded copper nickel pipe can also be supplied to match the specified flange arrangement, pipe size and connection requirements.
FAQ About Copper Nickel Socket Weld Flanges
Is a copper nickel socket weld flange suitable for seawater piping?
Copper nickel alloys are widely used in seawater-related piping because of their corrosion resistance. The final flange grade and configuration should be selected according to the seawater conditions, piping design and applicable project specification.
What is the difference between C70600 and C71500?
C70600 is 90/10 copper nickel, while C71500 is 70/30 copper nickel. The two grades have different alloy compositions and should be selected according to the applicable material standard and service requirements.
Are Class 150 and Class 300 copper nickel socket weld flanges available?
Yes. HC Aluminum supplies copper nickel socket weld flanges for ASME B16.5 Class 150 and Class 300 requirements.
Are Flat Face and Raised Face configurations available?
Yes. Flat Face (FF) and Raised Face (RF) configurations can be supplied according to the flange arrangement and project specification.
Can HC Aluminum manufacture a copper nickel socket weld flange from a drawing?
Yes. Drawing-based production can be reviewed according to the required material grade, nominal size, pressure class, bore, drilling, facing and inspection requirements.
What information should I provide for a copper nickel flange quotation?
The most useful information includes nominal pipe size, pressure class, copper nickel grade, flange facing, pipe schedule or wall thickness, quantity, applicable standard and drawing where available.
How is a socket weld flange connected to the pipe?
The pipe is inserted into the flange socket until it reaches the internal shoulder. The pipe-to-flange connection is then secured by a fillet weld around the external junction, while the flange face is connected to the mating flange with the specified gasket and bolting arrangement.
What is the difference between a socket weld flange and a slip-on flange?
A socket weld flange receives the pipe into a recessed socket and is secured by a fillet weld. A slip-on flange is positioned over the pipe and uses the applicable fillet-weld arrangement. The appropriate configuration depends on the piping design, available space, fabrication practice and project specification.
Can C70600 and C71500 be used interchangeably?
They should not be treated as automatic substitutes. Although both are copper nickel alloys used in marine and seawater applications, the applicable material specification and service conditions should determine the selected grade.
What flange standards does HC manufacture?
HC supplies different copper nickel flange types to standards including ASME B16.5, DIN and EEMUA according to the specific flange design and project requirement. For this socket weld product, ASME B16.5 Class 150 and Class 300 are the primary configurations presented on this page.
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