CuNi flanges

CuNi flanges, also can be called as copper nickel flanges.As the professional cuni flanges manufactuerer and supplier, shihang has own forging manufacturer for 15-years and produced cuni flanges for 20 years. Shihang cuni flanges have the good ability of anti-corrision, reasonable price and fast delivery.

  • Raw Material:CuNi 90/10(C70600) , CuNi 70/30 ( C71500 ), CuNi10Fe1.6Mn, 7060X,CuNifer
  • MTC EN 10204 3.1 Certifacte is available
  • Seaworthy Wooden Case Packaging
  • Tolearance:100% meet the standard.
CuNi Flanges
EEMUA 145 Flanges

CuNi flanges Specification

Specifications : ASTM B151 UNS C70600, CuNi10Fe1.6Mn, 7060X

Dimensions : DIN86037,DIN 86033,DIN2633,DIN2632,DIN 86036,EEMUA 145,EEMUA 234, ANSI/ASME B16.5, B 16.47 Series A & B, B16.48, BS4504, BS 10, EN-1092, etc.

Standard : EEMUA Flanges, DIN Flanges, JIS Flanges, ANSI Flanges, ASME Flanges, BS Flanges, EN Flanges,

Size : 1/2″ to 24”

Class / Pressure : 150#, 300#, 600#, 900#, 1500#, 2500#, PN6, PN10, PN16, PN25, PN40, PN64 etc.

Flange Face Type : Flate Face (FF), Raised Face (RF),

Grades : Copper Nickel 90/10 (C70600 ), Cupro Nickel 70/30 (C71500), UNS C71640

Type of Flanges:

Compositer Weld Neck Flanges, Composite Slip On Flanges, Collar, Inner Flanges,Weld Neck Flanges – WNRF,Socket Weld Flanges – SWRF,Slip On Raise Face – SORF,Blind Raise Face – BLRF

Lap Joint,Screwed ( Threaded ),Long Weld Neck,Reducing,Spectacle Blind

CuNi flanges Description

CuNi Flanges CuNi 90/10 70600 Flanges Manufacturer and Supplier

Shihang CuNi Flanges, also called Copper Nickel Flanges, are made from high-grade material, with an accurate balance of Ni, Fe, Mn, C, Pb, S, P, Zn, and Cu in varying proportions. They are DIN, EEMUA and ASME compliant CuNi Flanges available as 90-10 CuNi Flanges and 70-30 CuNi Flanges.

Shihang CuNi Flanges are the best flanges in the market with superior tensile strength, precise dimension tolerance, sturdy structure, excellent corrosion resistance, and erosion resistance.

Our CuNi Flanges offer a perfect solution in marine applications, shipbuilding, chemical processing, oil & gas, etc.

Shihang CuNi Flanges come as CuNi Composite Weld Neck Flange, CuNi Composite Slip On Flange, CuNi Weld Neck Flange, CuNi Slip On Flange, CuNi Socket Weld Flange, CuNi Blind Flange, and CuNi Threaded Flange.

With an accurate balance of chemical composition, Shihang CuNi Flanges withstand harsh environmental conditions such as fluctuating temperature, turbulent flow, high pressure or high-velocity flow.

Shihang CuNi Flanges dimensions vary depending on the DIN 2632, DIN 2633, DIN 2642, DIN 86033, DIN 86037, EEMUA 145 or EEMUA 234 and ASME B16.5 standards. Both the raised face and flat face are available.

Our clients can choose from different thickness, pressure ratings, and sizes of Shihang CuNi Flanges.

With over 20 years in CuNi Flange manufacturing, Shihang has the know-how and experience to deliver cost competitive and exceptional quality CuNi Flanges.

Shihang CuNi Flanges are trusted by over 500 companies globally for distinct quality from other competitors. Our team helps in custom CuNi Flange design process, from a CAD drawing, specifications through to the production process.

Shihang invests in strict quality control, working with third-party quality inspection institutions. With our 4 production facilities and a wide range of material stock, Shihang guarantees a fast turnaround on both standard and custom CuNi Flanges.

Shihang team is available 24/7 to serve you better.

Contact us today, and our team will answer all your questions on CuNi Flanges.

CuNi Flanges: The Ultimate FAQ Guide

In this guide, you’re going to learn everything about CuNi Flanges.

It covers copper-nickel grade, standard specification, benefits, classification, surface finishing options, and uses amongst others.

Let’s dive right in:

What are CuNi Flanges?

CuNi flanges are external rims whose function in a piping system is to offer strength and to act as a connecting point.

They also facilitate easy cleaning, modification, and inspection of the piping system.

Where can you use CuNi Flanges?

You can use Cuni flange in the following industries:

  • Shipbuilding
  • Offshore mining
  • Power generation
  • Desalination plants
  • food process plants

What are CuNi Flanges used for?

Depending on the type of CuNi flanges, you can use them to connect cupronickel pipes, block a section of the piping system.

You can also use them to terminate the end of a cupronickel pipe.

Copper nickel flanges

Copper-nickel flanges

What are the Standards for Cupronickel Flanges?

The primary standards for quality Cupronickel flanges are:

  • ASME B16.5 standards
  • EEMUA 145/EEMUA 234 standards
  • DIN 86036 standards
  • ANSI standards
  • BS standards
  • EN standards
  • JIS standards

What are the Types of CuNi Flanges?

The main types of CuNi flanges include:

· Copper Nickel Threaded Flange

Threaded copper nickel flanges

Threaded copper nickel flange

This is a type of flange where the internal bore has threads that match the male threads of copper-nickel pipes.

You can also refer to this type as CuNi screwed flange.

Its use is mainly in pipes that have external threads.

This is because the threads present are responsible for connecting the flanges to the piping system.

CuNi threaded flanges are also standard in shipbuilding, desalination plants, power generation plants, offshore oil platforms, water piping, etc. additionally, you can use CuNi threaded flanges in:

i. Small diameter and high-pressure applications

ii. Highly flammable or explosive areas where welding results in a fire. This is because CuNi threaded flanges do not require welding during the connection process.

· Cupronickel Blind

Blind flange

Blind flange

This refers to a solid piece of metal made from copper-nickel alloy, which lacks holes on the surface.

Also, this ensures there is a smooth flow of fluid.

The only holes on a copper-nickel blind flange are for bolts that you will use to secure it to the piping system.

This type of copper-nickel flange is common in:

a) Carrying out tightening and strengthening tests in copper-nickel pipe systems

b) Isolation of certain piping system

c) Isolation of equipment or devices in a piping system

d) Cleaning and repairing of piping system

· Copper Nickel Lap Joint Flanges

Copper nickel lap joint flange

 Copper-nickel lap joint flange

Cupronickel lap joint flange features a raised face that has a grooved machined on it to accept a metal ring gasket.

The use of this cupronickel flange is common in:

a) A piping system that is frequently assembled and disassembled often.

b) In corrosive applications. However, you have to change the flange joints in these applications frequently.

c) Complicated applications

· Copper-nickel Composite Slip-on Flange

Composite slip on flange

Composite slip-on flange

This is an altered version of the standard slip-on flange consisting of an inner and outer flange.

The inner flange is also referred to as stub or collar end.

Copper-nickel composite slip-on flange consists of two materials, that are copper-nickel alloy and carbon steel.

The copper-nickel forms the stub or collar while the carbon steel forms the outer flange.

You can use it in non-critical applications, have low temperature and low pressure.

Some of these applications include shipbuilding, sewerage piping system, power generation, offshore oil and gas platforms, and desalination plants.

· Copper-nickel Socket Weld Flange

 Socket weld flange

 Socket weld flange

Copper-nickel socket weld flange features a flange bore with a shoulder like section, also called recessed area or counterbore.

It also has a recessed area, which determines how deep you can insert the CuNi pipe.

This means there are two holes in a cupronickel weld neck flange.

That is a counterbore which has a diameter that is relatively larger than the pipe’s outer diameter.

This means you need to insert the pipe the same way as a slip-on flange.

The other hole is relatively smaller and has a diameter which is equal to that of the pipe.

This implies that the pipe will rest on the shoulder like section.

The use of this type is common in applications where:

a) The use of a cupronickel threaded pipe causes leakages as a result of temperature fluctuation.

b) The diameter of a pipe is small to handle high pressure.

c) There is a need to align the piping system properly

d) It is impossible to weld the internal section of the piping system and the CuNi flange.

What are the Benefits of Copper Nickel Flanges?

  • Easy to install and uninstall – You can actually install and tighten these flanges by yourself by the following instruction on the guideline.
  • Offer tight and secure flanging mechanism for your cupronickel piping system
  • Durable due to their anti-corrosion, anti-fouling characteristics.
  • Ideal for use under high temperature.

What are the Features of CuNi Flanges?

The main features of CuNi flanges are:

  • Easy installation procedure.
  • High pressure and stress resistance
  • High erosion resistance
  • Excellent heat transfer
  • Resistance to corrosion
  • Resistance to biofouling

What is Cupronickel Flange Grade?

This refers to the different alloys of cupronickel that are common in the manufacturing of flanges.

The difference in the alloys is the different quantities of copper and nickel present in the cupronickel.

The common grades include:

  • 6Mn
  • 7060X
  • CuNifer
  • Copper Nickel 90/10 (C70600 )
  • Cupro Nickel 70/30 (C71500)

What are the Dimensions of CuNi Flanges?

The dimensions of CuNi flange adhere to ASME B16.5, DIN 86033, DIN 86037 or EEMUA 145 standards.

A reliable manufacturer can help you with a dimension datasheet and explain it to use on how to use it.

What is Cupronickel Flange Schedule?

Schedule (Sch) is a common standard in North America.

It defines the wall thickness of a given cupronickel flange.

Basically, a given cupronickel flange has a high Sch.

It means it has thick walls.

Flanges that have high Sch are usually:

  • Heavier
  • Have more CuNi materials
  • Relatively expensive

What factors should you consider when Selecting Cupronickel Flanges?

You can consider the following factors when selecting a quality cupronickel flange:

· Cupronickel Flange Type

The different types of cupronickel flanges have different installation procedures.

You need to pick one that fits the requirements of your piping system.

Of key consideration, here are the checking the top to determine if it has a flange face, a threaded bore, or a lap joint.

Check also the bottom to determine its design.

·  Cupronickel Size

Among the factors to consider here include the standards applicable, that is, either ANSI, DIN, or JIS.

Check also the actual measurements of the flange, including the outer and inner diameter.

· Thickness

The thickness of a cupronickel flange is essential in determining the pressure that it can hold.

A thicker flange can withstand a higher pressure when you compare to a thinner one.

· Bolt Holes

The bolt holes help in determining the pressure class and the right size of a cupronickel flange to use.

Here, you need to consider the pitch circle diameter, the number of bolt holes, and the exact size of the individual bolt holes present on the flange.

A thicker bolt translates to a stronger bolt, which implies that it can withstand higher pressure.

· Standards

Available standards that you can select your cupronickel flanges from include DIN, ANSI, or JIS. The standards you select should correspond to that of your piping system.

How does DIN and ANSI CuNi Flanges compare?

DIN is a European standard that specifies cupronickel flanges while ANSI is an American standard.

The unit of measurement for DIN CuNi flanges is mm and bar, while for ANSI, flanges are inches and psi.

DIN CuNi flanges have an outside diameter of 100mm, while ANSI CuNi flanges have an outside diameter of 125mm.

Which Surface Finishing Options are available for CuNi Flanges?

The available surface finishing options available for CuNi flanges are:

· Stock Finish

Gasket surface formation is through a continuous spiral groove that is generated by a round-nosed tool with a 1.6mm radius.

This is normally at a feed rate of 0.8mm for each revolution having a 0.15mm depth.

The result is a roughness range of Ra 3.2- 12.5mm.

· Smooth Finish

There is no visible tool marking in this type of finish.

A continuous spiral groove forming the gasket contact surface is responsible for the smoothness.

The groove normally has a round-nosed tool with a radius of 0.8mm and a feed rate of around 0.3mm for each revolution.

This is at a depth of 0.05mm.

The result is a roughness range of between Ra 3.2 and 6.3mm.

This type of finish is common in low pressure and large diameter piping system.

· Spiral Serrated

It uses a 90-° tool generating a continuous spiral groove with a “V” geometry having 45° angled serration.

The “V” geometry differentiates it from the stock finishing option.

· Concentric Serrated

It is a type of finishing option that has a concentric groove with even serration spaces across the face.

It uses a right-angle tool to create the grooves.

· Coldwater Finish

The flange finishing has a mirror-like appearance.

This option is ideal for metal to the metal surface contacting, that is, without the gasket.

What is the Maximum Pressure Rating for CuNi Flanges?

The maximum pressure rating depends on the alloy grade of CuNi flange.

However, this ranges between 150psi-2500psi.

How much does CuNi Flange Cost?

The cost of CuNi flange differs depending on several factors.

Key among them are:

  • CuNi alloy grade
  • The length
  • Type of CuNi flange
  • CuNi flange manufacturer

How do you Manufacture CuNi Flange?

Different types of CuNi flanges have different manufacturing processes.

The main types and their manufacturing processes are:

 Manufacturing pipe flanges

Manufacturing pipe flanges

1) Copper Nickel Blind Flange

The manufacturing process of CuNi nickel blind flange entail:

  • Test quality of copper-nickel material for consistent chemical composition
  • Cutting copper-nickel bar to the right size
  • Forging and forming copper-nickel bar to right size and shape of CuNi blind flange
  • Machining copper-nickel blind flange
  • Heat treatment of copper-nickel blind flange
  • Cupronickel blind flange quality testing
  • Marking and packaging copper-nickel blind flange
  • Packing CuNi flange in a packaging material that can withstand shipping conditions.

Remember, there is a need for quality control in every step of the fabrication process.

This ensures quality CuNi flange production that has a suitable dimension and tolerance.

2)  Copper Nickel Composite Slip-on Flange

The production process of this type of CuNi flange involves:

  • Raw material quality inspection for both the internal and external flange.
  • Cut copper-nickel alloy bar to suitable dimensions
  • Forge and form the cut copper-nickel bar to form stub end of the composite slip-on flange
  • Cutting of the A105N carbon steel to suitable dimension, then forging and forming of the outer flange of a copper-nickel composite slip-on flange
  • Machining of the outer flange through the drilling of bolt holes
  • Subjecting the internal and external flange to a given heat treatment
  • Inspect and mark the copper-nickel composite slip-on flange. Such marks include pressure ratings, dimensions standards, lot number, and material grade.
  • Packing CuNi flange in a packaging material that can withstand shipping conditions.

3)  Copper Nickel Threaded Flange

The manufacturing process of a copper-nickel threaded flange involves the following crucial steps:

  • Raw material quality inspection, including dimensional and visual checks.
  • Carrying out chemical and preservation analysis of the raw material.
  • Material cutting. This includes weight measurement, cut surface checks, and marking
  • Flange forging which includes controlling the temperature during the forging process.
  • Heat treatment involves normalizing, solution treatment and mechanical testing
  • Forging rolling where you check the dimension, temperature, material grade, and weight measurement.
  • Rust prevention method including yellow paint coating and black paint coating
  • Final inspection includes dimension size inspection, visual testing, and nondestructive testing.
  • Packaging using the required packaging material

4) Cupronickel Socket Weld Flange

Cupronickel Socket Weld Flange goes through the following production process:

  • Raw material quality inspection, including dimensional and visual checks.
  • Carrying out chemical and preservation analysis of the raw material.
  • Material cutting. This includes weight measurement, cut surface checks, and marking
  • Flange forging which includes controlling the temperature during the forging process.
  • Heat treatment involves normalizing, solution treatment and mechanical testing
  • Forging rolling where you check the dimension, temperature, material grade, and weight measurement.
  • Rust prevention method including yellow paint coating and black paint coating
  • Final inspection includes dimension size inspection, visual testing, and nondestructive testing.
  • Packaging using the required packaging material

Is there a difference between CuNi Flanges and CuNi Fittings?

 Copper nickel pipe fitting

Copper-nickel pipe fitting

Both copper nickel pipe fittings and copper-nickel pipe flanges are used to connect pipes or other accessories in the piping system.

However, pipe fittings tend to offer more flexible options such as dividing or combining flow, which is not the case for most CuNi pipe flanges.

Moreover, Cupronickel pipe flanges have thick and heavy construction design.

Besides, most of them provide a bolted connection.

On the other hand, nearly all Cupronickel pipe fittings do not offer bolted connections.

Compared to CuNi flanges, they are lightweight and thin in size.

How do you Connect Cupronickel Flanges to CuNi Pipe System?

Connecting CuNi flanges to a CuNi pipe system varies depending on the type of flange you are using.

These types include:

· CuNi Threaded Flange

When connecting this type, first, you need a copper-nickel pipe with matching external threads to that of the CuNi threaded flange.

Then you screw-in the Cupronickel threaded flange onto the copper-nickel pipe.

Make sure to tighten it for a firm connection that can withstand a given pressure flow.

· CuNi Blind Flange

Ensure the copper-nickel pipes and the Cupronickel blind flange have an equal number of holes.

Next, you have to clean the surfaces of CuNi pipe and copper-nickel blind flange.

Then you place a gasket on the copper-nickel blind flange (remember, the CuNi blind flange, the pipe, and the gasket should have the same number of holes as well as the sizes.

Place the blind flange inside the CuNi pipe and use bolts and nuts to fix it in position securely.

Lastly, ensure you tighten all the bolts for a secure sealing mechanism

· Copper Nickel Composite Slip on a Flange

Inset the composite slip-on flange into a copper-nickel pipe with the backing flange being active.

Once it is placed, you have to weld the internal and external sides of the composite slip-on flange.

Meanwhile, press the backing flange together to give a reliable and robust connection.

Ensure the flange is tightly fixed.

· Cupronickel Socket Weld Flange

The connection process of this flange involves:

i. Selecting the right cupronickel pipes and socket weld flange that have the correct dimensions.

ii. Inserting an end of the cupronickel weld flange to the other end of the cupronickel pipe.

iii. Pushing off the CuNi pipe until it reaches the shoulder section of the flange.

iv. Pulling it back to give room for expansion of the CuNi pipe and CuNi flange.

v. Fillet welding the top of the CuNI socket weld flange and CuNI pipe.

vi. Using bolts to tighten the CuNi Socket weld flange on the piping system

This step ensures you have a CuNI weld flange that offers a smooth flow of fluid.

What is the difference between NPT and BSPT Thread Types in CuNi Flanges?

The main difference between NPT and BSPT thread types is the configuration of the thread form and pitch.

Remember, the National Pipe Taper (NPT) is an American standard, although it has been adopted globally.

On the other hand, British Standard Pipe Taper (BSPT) is common within the European economic region, although it has been adopted globally too.

How do you Specify CuNi Flanges?

The following considerations are key when specifying CuNi flanges:

  • The material grades
  • Standard specification
  • Dimensions
  • Class or pressure rating
  • Flange face type
  • Size of the flange and application

Which Copper Nickel Flanges are best for Piping Systems with Thermal Cycles?

Copper Nickel Socket Weld Flange is ideal for piping systems that have a thermal cycle.

Their welding properties make them ideal for this use.

Which Industries use CuNi Flanges?

CuNi flanges are suitable for industries where corrosion, erosion, and biofouling resistance is a priority, besides excellent mechanical properties.

Copper-nickel flanges are common in desalination plants, offshore mining, shipbuilding industries, food processing plants, desalination, water distribution, and power generation plants, amongst others.

Are there Limitations of using Copper Nickel Flanges?


There are limitations to the use of copper-nickel flange.

For instance, the initial cost of purchasing them is relatively higher.

This is due to their quality of a material.

Also, there is a need for frequent maintenance due to wear and while operating.

This adds up to the overall cost of your copper nickel flange.

How can you Inspect the Quality of Cupronickel Pipe Flanges?

When inspecting the quality of cupronickel pipe flange, you need to consider the following:

  • Test and verify the chemical composition of the cupronickel alloy grade
  • Control the quality of a cupronickel pipe flange forging and production processes.
  • Control the quality of the machining and heat treatment process
  • Get the correct size for the inner and outer diameter, bolt hole, and the shoulder length and thickness.
  • Check the alignment.

More importantly, a given cupronickel pipe flange must conform to dimension standard specifications.

What is the Chemical Composition of Cupronickel Flanges?

The chemical composition of cupronickel flanges depends on the standard type.

Ideally, the common standards have the following chemical composition

DIN 86019

DIN 86019 2.1972 (CuNi10Fe1.6Mn)
Cu% Ni% Fe% Mn% C% Pb% S% P% Zn% other
Rem. 9.0-11.0 1.5-1.8 0.5-1.0 Max. 0.05 Max. 0.01 Max. 0.005 Max. 0.02 Max 0.05 _


EEMUA 144 UNS 7060X
Cu% Ni% Fe% Mn% C% Pb% S% P% Zn% other
Balance 10.0-11.0 1.5 – 2.0 0.5 – 1.0 Max 0.05 Max 0.01 Max 0.02 Max 0.02 Max 0.20 0.30

ASME B36.19M

ASTM B466     C70600
Cu% Ni% Fe% Mn% C% Pb% S% P% Zn% other
Balance 9.0 – 11.0 1.0 – 1.8 Max 1.0 Max 0.05 Max 0.02 Max 0.02 Max 0.02 Max 0.50 _

What is the CuNi Flange Face Type?

  • CuNi flange face type refers to the outer surface of the flange which hosts the gasket. There are six main types of CuNI flange face types:
    Flat face flange (FF)
  • Raised face flange (RF)
  • Ring joint flange (RTJ)
  • Lap joint flange
  • Male and female flange (M&F)
  • Small and large tongue-and-groove flange (T&G)

How do you Package Cupronickel Flange for Shipping?

The process of packing involves:

Printing of the necessary information, including dimensions, grade, and standard specifications.

You can do this on the outer package or the individual CuNI flanges.

Proper packaging should include wrapping the cupronickel flanges using plastic covers and wrapping them together.

However, there is a need for separation of the individual pipes by using a plastic sheet to reduce abrasion.

After that, they are placed inside a wooden box and securely locked ready for shipment

How do you Measure Copper Nickel Flange?

The internal diameter usually describes the measurement of a copper-nickel flange.

The process of measuring a copper-nickel flange entail:

  • Take a tape measure, then place the copper-nickel flange on a flat surface
  • Identify two opposite bolt holes on the copper-nickel blind flange (i.e., on the extreme ends)
  • Measuring the distance from the middle of the first bolt hole to the middle of the second bolt hole on the other side of the copper-nickel flange
  • You can use this measurement to identify the part number or the size of your copper nickel flange.

However, most copper nickel flanges manufacturers typically give a reference chart or table that can help you estimate the right size.

Can you use Gaskets with CuNi Flanges?


You can use a gasket with a CuNi flange.

However, there are several factors that you have to consider when selecting the right gasket for your CuNi flange.

They include the type of fluid, the operating pressure, and the temperature.

Why Import CuNi Flanges from China?

Here are some of the reasons why you should consider importing copper nickel flanges from China:

· Cost-Effective

The overall importation cost of your CuNi flanges from China is lower.

Also, this consists of the manufacturing cost and the importation tax.

This implies high-profit margins if you are purchasing them for resale.

If you are buying for your use, you will save a lot.

· Quality CuNi flanges

Most manufacturers in China tend to manufacture quality CuNi flanges that meet internationally recognized standards.

This is due to the high competition amongst the manufacturers.

Quality CuNi flanges give you quality service with a guaranteed warranty.

· Timely Delivery

Most Chinese manufacturers adhere to the production time for their CuNi flanges.

You, therefore, have an assurance of the delivery of your CuNi flanges within the time you agreed with your manufacturer.

You can, therefore, plan as you wait for your CuNi flanges

In short, before you choose CuNi flanges, it is important that you consider everything mentioned in this guide.

At Shihang, we manufacture high quality and reliable copper nickel flanges.

For questions or inquiries about CuNi flanges, contact Shihang now.

Let’s Shihang Skyrocket Your Business

You can also send the inquiry to email: directly.

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