Introducing DIN Flanges: A Comprehensive Guide to the German Standard

DIN Flanges

Introducing DIN Flanges: A Comprehensive Guide to the German Standard

If you work in the industrial sector, chances are you have encountered flanges at some point. Flanges are crucial components in piping systems as they provide a secure and leak-free connection between pipes, valves, pumps, and other equipment. However, with so many flange standards out there, it can be challenging to select the right one for your specific application.

This blog will focus on DIN flanges, which are widely used in Europe and conform to the German standard DIN (Deutsche Industrie Norm). We will provide a comprehensive guide to DIN flanges, covering everything from their design and construction to their applications and benefits.

What is a DIN flange?

A DIN flange is a type of flange that conforms to the German standard DIN (Deutsche Industrie Norm). DIN flanges are used in various industrial applications for connecting pipes, valves, pumps, and other equipment. They are characterized by their metric dimensions and bolt-hole patterns, which differ from other flange standards such as ANSI or ASME.

DIN flanges come in several types, including welding neck, slip-on, threaded, and blind flanges. Each type of DIN flange is designed for a specific application and has its own set of unique features and benefits.

DIN Flanges

What is the difference between ANSI and DIN flanges?

DIN and ANSI are two different standards for designing and manufacturing flanges that are used in industrial applications. The use of DIN and ANSI flanges is primarily determined by location and regional standards.

ANSI and DIN flanges

DIN is typically used in Europe, while ANSI is more commonly used in the United States. As a result, many factories in North America have piping that is ANSI certified, while similar plants in European countries have DIN piping.

Besides, there are some other differences between ANSI and DIN flanges.

  1. Bolt Hole Patterns: The bolt hole patterns of ANSI and DIN flanges are also different. ANSI flanges typically have a bolt-hole pattern that is based on a 4- or 8-bolt hole configuration, while DIN flanges have a bolt-hole pattern that is based on a 4-, 8-, or 16-bolt hole configuration.
  2. Pressure Ratings: The pressure ratings of ANSI and DIN flanges are also different. ANSI flanges typically have a higher pressure rating than DIN flanges, which makes them suitable for applications that require higher pressure capabilities.
  3. Applications: ANSI flanges are commonly used in the United States and other parts of the world, while DIN flanges are mainly used in Europe. Therefore, the choice of flange standard is often determined by the location and requirements of the application.

Here’s a conversion table for DIN and ANSI values

ANSI NUMBER(Inch) DIN NUMBER(mm)
1/2 15
3/4 20
1 25
1-1/4 32
1-1/2 40
2 50
2-1/2 65
3 80
4 100
5 125
6 150
7 175
8 200
9 225
10 250
12 300

Are DIN and ANSI flanges compatible?

DIN and ANSI flanges are generally not compatible due to differences in their dimensional standards, bolt-hole patterns, and face-to-face dimensions. For example, DIN flanges have metric measurements and bolt hole patterns, while ANSI flanges have imperial measurements and bolt hole patterns.

This means that it is generally not recommended to connect a DIN flange to an ANSI flange or vice versa without using an adapter or transition flange that is specifically designed to bridge the gap between the two different flange standards.

When connecting DIN and ANSI flanges, using an adapter or transition flange can help ensure a proper fit and alignment between the two different flanges. This is essential for preventing leaks and ensuring the safe and reliable operation of the system.

An adapter or transition flange is designed to bridge the gap between the two different flange standards by providing a common interface that allows the flanges to be connected securely and without leaks.

The adapter or transition flange is typically made from a material compatible with the DIN and ANSI flanges. It is designed to have the appropriate dimensions and bolt hole patterns to allow for a proper fit.

DIN Flanges

DIN and Pressure Rating

DIN flanges are rated according to their pressure capability, indicating the maximum pressure the flange can withstand without leaking or failing. DIN flanges are rated using the PN (Pressure Nominal) system, which is based on the maximum allowable pressure at 20°C in bars.

The PN rating of a DIN flange determines the maximum pressure that the flange can withstand. The most common PN ratings for DIN flanges are PN6, PN10, PN16, PN25, PN40, and PN64. The higher the PN rating, the higher the pressure that the flange can withstand.

For example, the most common one is DIN PN16 Flange. These flanges are designed to withstand a maximum pressure of 16 bar at a temperature of 120°C.

The standard dimensions of DIN PN16 flanges include the nominal diameter (DN), the flange thickness (C), the bolt circle diameter (BCD), the bolt hole diameter (BD), and the number of bolt holes. These dimensions ensure that the flange can be properly installed and connected with other components of the piping system.

It is important to choose a DIN flange with a PN rating that matches the pressure requirements of the piping system. Choosing a flange with a lower PN rating than required can result in the flange failing under pressure, while choosing a flange with a higher PN rating than required can result in unnecessary expense and weight.

DIN Flanges

DIN Flange Measurements

The measurements of a DIN flange depend on the type and size of the flange and can vary slightly depending on the manufacturer. Here are the common measurements for DIN flanges:

  1. Nominal Size: This is the size of the pipe or equipment that the flange is designed to connect. DIN flanges come in a range of nominal sizes, from DN10 to DN4000.
  2. Flange Diameter (D): This is the outside diameter of the flange, measured from one edge to the opposite edge. The diameter of the flange corresponds to the size of the pipe it will be connected to.
  3. Bolt Circle Diameter (BCD): This is the diameter of the circle that passes through the center of each bolt hole. The bolt circle diameter of the flange will vary depending on the nominal size of the flange.
  4. Bolt Hole Diameter (BD): This is the diameter of each bolt hole. The number and size of bolt holes on a DIN flange will vary depending on the nominal size of the flange.
  5. Flange Thickness (C): This is the thickness of the flange, measured from the top surface to the bottom surface. The flange thickness can vary depending on the pressure rating and the nominal size of the flange.
  6. Raised Face Diameter (R): This is the diameter of the raised face on the flange. The raised face provides a sealing surface for gaskets and helps to prevent leaks.

DIN Flanges

How to Choose DIN Flanges

Ordering DIN flanges requires careful consideration of the specific requirements of the piping system and the application. It is important to determine the required materials, pressure ratings, and appropriate flange size.

If DIN flanges are required, the dimensions and pressure rating will differ from non-DIN flanges, and it is essential to refer to the applicable standards to ensure that the flanges are manufactured to the correct dimensions and tolerances.

It is also important to consider other factors, such as the type of gasket required, the type of bolts and nuts needed, and any special requirements or considerations for the installation or operation of the flange.

Here is a checklist of the factors to consider when choosing DIN flanges:

  • Piping System: The first thing to consider when selecting a DIN flange is the type of piping system you have. This includes the size and type of pipe, the pressure rating, and the temperature range. Make sure to choose a DIN flange that is compatible with your piping system.
  • Material: DIN flanges are available in a variety of materials, including carbon steel, stainless steel, and cast iron. Choose a material that is compatible with the media flowing through the piping system and that can withstand the pressure and temperature conditions.
  • Flange Type: There are several types of DIN flanges, including weld neck, slip-on, threaded, and blind flanges. Choose the type of flange that best suits your application.
  • Flange Size: DIN flanges come in a range of sizes, from DN10 to DN4000. Make sure to choose the correct size for your piping system.
  • Pressure Rating: DIN flanges are designed to withstand different pressure ratings, ranging from PN6 to PN100. Choose a flange with a pressure rating that is suitable for your piping system.
  • Standards: DIN flanges conform to specific standards, such as DIN 2501 or DIN 2633. Make sure to choose a DIN flange that conforms to the appropriate standard for your application.
  • Gasket Type: The type of gasket used with a DIN flange is also important. Choose a gasket that is compatible with the media flowing through the piping system and that can withstand pressure and temperature conditions.

Conclusion

In conclusion, DIN flanges are an important component of many piping systems and are widely used in Europe and other parts of the world. DIN flanges are designed to meet specific standards and are available in a range of materials, sizes, and pressure ratings to meet the requirements of different applications.

It is important to work with a knowledgeable supplier who can provide the necessary support and expertise to ensure that you get the right DIN flanges for your application.

As a professional flange supplier with experience of over 30 years, Taiyuan Forging is always dedicated to providing high-quality forging products. If you have any further inquires, please don’t hesitate to contact us.