Overview of flanges and accessories

Flanges and accessories are key components of pipeline systems, ensuring the connection between pipelines, safety and overall reliability of the system. Flanges are mainly used for detachable connections between pipelines, while pipe fittings include various components for changing direction, branching, diameter conversion, etc. The following will introduce the types, applications and standards of flanges and common accessories in detail.

1. Overview of flanges

1.1 Functions of flanges

Realize the connection between pipelines, which can be easily disassembled, repaired and cleaned.

Enhance the strength of the pipeline system and have high pressure resistance.

Cooperate with gaskets to ensure sealing and avoid medium leakage.

1.2 Classification of flanges

Classification by structure:

1. Slip-On Flange: The pipe is inserted into the flange and then welded, which is easy to install and suitable for medium and low pressure systems.

2. Weld Neck Flange: It has a long neck and high welding strength, suitable for high pressure and high temperature environments.

3. Threaded Flange: No welding is required, suitable for small diameter or flammable environment.

4. Socket Weld Flange: Commonly used for small diameter and high pressure pipelines.

5. Blind Flange: used to close the end of the pipe.

Classification by sealing surface:

1. Flat sealing surface (FF): used for low-pressure pipes.

2. Raised face sealing surface (RF): the most common type, suitable for medium and high pressure systems.

3. Concave and convex face seal (M/F): used in high pressure environments, with better sealing performance.

1.3 Flange standard

ASME B16.5: American standard flange standard, used in the petroleum and chemical industries.

EN 1092: European standard flange standard, suitable for various industrial pipelines.

GB/T 9119: Chinese standard flange.

2. Common pipe fittings and accessories

2.1 Elbow

Used to change the direction of the pipe, common angles are 45°, 90°, and 180°.

Long radius elbow and short radius elbow: long radius is used for smooth flow, short radius is used for space-constrained occasions.

2.2 Tee and Cross

Tee: used to divide the pipeline into two branches. Common types include equal-diameter tees and reducing tees.

Cross: used to connect four pipelines, usually used in special pipe network systems.

2.3 Reducer

Concentric Reducer: both ends are on the same axis, used for vertical pipelines.

Eccentric Reducer: used for horizontal pipelines to avoid gas accumulation in the pipeline.2.4 Cap

Used to seal the end of the pipeline to prevent medium leakage.

2.5 Gasket

Located between two flanges, used to enhance sealing performance. Common gasket materials include rubber, graphite, and stainless steel composite gaskets.

3. Connection methods of flanges and accessories

1. Welding connection: commonly used for metal pipelines, such as butt welding and flat welding.

2. Threaded connection: suitable for small-diameter, low-pressure pipelines.

3. Flange connection: connect two sections of pipes with bolts and gaskets, which is convenient for disassembly and maintenance.

4. Application areas of flanges and pipe fittings

Oil and gas industry: butt welding flanges and long radius elbows are used in high-pressure pipeline systems.

Chemical and pharmaceutical: stainless steel flanges and tees are used for corrosion-resistant pipes.

Municipal engineering: PVC pipe fittings such as socket tees are used in water supply and drainage systems.

Power and energy: socket welding flanges and reducers are used in boilers and steam pipes.

5. Maintenance and management of flanges and pipe fittings

1. Regularly check the tightening status of flanges to avoid leakage caused by loose bolts.

2. Replace gaskets: Regularly check whether the gaskets are aged or damaged to ensure sealing performance.

3. Cleaning and anti-corrosion treatment of pipe fittings: lining or anti-corrosion coating measures should be taken in corrosive environments.

4. Use intelligent detection technology: use ultrasound or X-rays to detect the quality of flanges and welds.

6. Trends in the flange and fittings industry

1. Application of new materials: use high-strength alloy and composite flanges to improve corrosion resistance.

2. Green and environmentally friendly development: Accessory manufacturers develop recyclable materials to reduce carbon emissions.

3. Intelligent management system: Introduce the Internet of Things (IoT) to achieve remote monitoring of pipeline status.

4. Modular accessories: Develop prefabricated flanges and accessories to speed up installation and reduce the difficulty of on-site construction.

7. Conclusion

Flanges and pipe fittings are important components of industrial pipeline systems. They not only ensure the connection and sealing of pipelines, but also improve the overall safety and maintenance convenience of the system. In the future, with the development of new materials and intelligent technologies, flanges and accessories will become more environmentally friendly and efficient, and play a more important role in various industries.