In-depth introduction of neck flange: a guide to cooperation with Fortune 500 companies
Table of contents
- Introduction
- What is a neck flange
- Classification of neck flanges
- Applications of neck flanges
- Common specifications of neck flanges
- Standards for neck flanges
- Neck flanges VS flat weld flanges
- List of the top ten flange manufacturers in the world
- Summary
Introduction
Have you ever purchased flanges of substandard quality? The loss to the project is immeasurable; so before purchasing flanges, we must first understand the detailed knowledge of flanges.
Today, Metleader engineers will introduce the neck flange in detail.
Neck flanges are very common in engineering applications. Do you know the classification, specifications, applications, standards and excellent manufacturers of neck flanges?
This article will take you to learn about these knowledge in detail.
What is a neck flange
Neck flange is a commonly used flange connection method, which is characterized by adding a neck height to the flange to enhance the strength of the flange.
Classification of neck flanges
Neck flanges are divided into two types: neck flat welding flanges (SO) and neck butt welding flanges (WN);
Applications of neck flanges
Neck-welded flanges are suitable for pipelines with higher pressures, which improves the strength and load-bearing capacity of the flange.
Neck-welded flanges have higher strength and rigidity, and are suitable for situations with higher pressures and temperatures or high sealing requirements.
Common specifications of neck flanges
The following is a table of commonly used neck flange specifications and dimensions for reference:
| Specification | Size（mm） |
| DN10 | Ф90×12 |
| DN15 | Ф95×14 |
| DN20 | Ф105×14 |
| DN25 | Ф115×16 |
| DN32 | Ф140×18 |
| DN40 | Ф150×16 |
| DN50 | Ф165×16 |
| DN65 | Ф185×18 |
| DN80 | Ф200×20 |
| DN100 | Ф220×22 |
| DN125 | Ф250×22 |
| DN150 | Ф285×24 |
| DN200 | Ф340×26 |
| DN250 | Ф395×28 |
| DN300 | Ф445×30 |
| DN350 | Ф505×34 |
| DN400 | Ф565×36 |
| DN450 | Ф615×38 |
| DN500 | Ф670×42 |
Standards for neck flanges
- American Standard ANSI standard is ANSI B16.5.
- European Standard EN standard is EN 1092-1.
- German Standard DIN standard is DIN 2633.
- Chinese Standard National Standard is GB/T 9119-2000.
Neck flanges VS flat weld flanges
Neck flange and flat welding flange are two common flange types, widely used in various pipeline connection scenarios.
Although they have certain similarities in function, there are significant differences in practical applications. The following will discuss the differences between the two in detail from multiple aspects.
Different structures
Neck flanges are usually made of forged steel and have a denser structure and high strength.
The neck design provides additional support and stability when connected to the pipe, and the transition between the neck and the flange is smooth, which helps to reduce stress concentration. Neck flanges require double-sided welding.
Flat-weld flanges are mainly made of ordinary steel plates and are formed by mechanical processing. They are relatively simple and low-cost. Flat-weld flanges only require single-sided welding.
Different applications
The nominal pressure range of the neck-welded flange is 1-25MPa, which is suitable for high-pressure and high-standard industrial occasions.
The nominal pressure range of the flat-welded flange is relatively low, usually between 0.6-4.0MPa, and is mainly used for the connection of low-pressure and medium-pressure pipelines.
Different testing requirements
The weld between the neck flange and the pipe is classified as a Class B seam, which has higher requirements for welding quality and requires more stringent testing.
The weld between the flat-weld flange and the pipe belongs to a Class C seam, which has relatively lower testing requirements.
List of the top ten flange manufacturers in the world
| Manufacturer’s full name | Headquarters | Main product areas |
| Tenaris | Luxembourg | Oil and gas pipeline flanges, nuclear power flanges |
| Vallourec | France | High pressure flanges, special alloy flanges |
| Taylor Valve Corporation | USA | Petrochemical flanges, custom high pressure flanges |
| Iraeta Energy Equipment | China | Wind power flanges, nuclear power plant forgings |
| Jiangsu Hengrun Heavy Industries | China | Wind power flanges, gas turbine components |
| WIKA Griesheim | Germany | Pressure measuring flanges, industrial standard flanges |
| Shanxi Tianbao Group | China | Wind turbine tower flange, pressure vessel flange |
| Emerson Electric | USA | Corrosion-resistant flanges and innovative sealing technology products |
| Beijing Metleader Pipeline Technology Inc. | China | Flange, non-standard flange |
| Nippon Steel Corporation | Japan | Special alloy flanges, high-strength flanges for ships |
Summary
By understanding the knowledge of neck flanges, we have a deeper understanding of the product, and when purchasing, we can better choose the manufacturer that suits our project.
Metleader also compiled a list of the top ten flange manufacturers in the world, which can also be used as a reference.
If you want to know more about flange pipe fittings, you can follow Metleader’s official website to learn more about products.
