German standard flange: How many flange connection methods are there?

Time

2023-06-13 09:56

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German standard flange: How many flange connection methods are there?
At present, many people do not know the German standard flange, and many people do not know what it is. In fact, flanges are very common in pipelines. So, what are the flange connection methods for German standard flanges?
German standard flange: How many flange connection methods are there?
1. Flat welding: only weld the outer layer, not the inner layer; There are three types of sealing surfaces commonly used for welding flanges of medium and low pressure pipelines with nominal pressure below 0.25MPa, namely smooth surface, concave convex surface, and grooved surface. Smooth surface is widely used, affordable, and cost-effective.
2. Butt welding: Both the inner and outer layers of the flange need to be welded, usually used for medium and high pressure pipelines. The nominal pressure of the pipeline is between 0.25 and 2.5 MPa. The sealing surface of the welded flange connection is uneven, and the installation is complex, resulting in high labor costs, installation methods, and auxiliary material costs.
3. Socket welding: generally used for pipelines with nominal pressure less than or equal to 10.0MPa and nominal diameter less than or equal to 40mm.
4. Loose sleeve: Generally used on pipelines with low pressure but corrosive media, this type of flange has strong corrosion resistance and is mainly made of stainless steel.
This type of connection is mainly used for the connection of cast iron pipes, rubber lined pipes, non-ferrous metal pipelines, flange valves, etc. Flange connection is also used for the connection between process equipment and flanges.
German standard flange: What is the process of flange connection?
Firstly, the connection between flanges and pipelines should meet the following requirements:
The center of the pipeline and flange should be on the same horizontal plane.
2. The center of the pipeline is perpendicular to the flange sealing surface by 90 degrees.
3. The position of flange bolts on the pipeline should be consistent.
German standard flange: What are the requirements for flange gaskets?
1. The flange gaskets of the same pipe and pressure should be the same, and they can be exchanged in the future.
2. For pipelines with rubber plates, choose rubber gaskets, such as water pipes.
The principle of gasket selection is to choose a gasket with a smaller width as much as possible, and follow it on the premise that the gasket will not be crushed.
German standard flange: What is the flange connection flange like?
1. Check if the specifications of flanges, bolts, and gaskets meet the requirements.
2. The sealing surface should be kept smooth, clean, and free of burrs.
3. The threads of the bolts should be intact and naturally embedded.
4. The gasket texture should be flexible, not prone to aging, and the surface should be free of defects such as damage, wrinkles, and scratches.
Before assembling the flange, clean the flange, remove oil, dust, rust, and other debris, and remove the sealing wire.
German standard flange: How to assemble the flange?
1. The flange sealing surface is perpendicular to the center of the pipeline.
2. Bolts of the same specification are installed in the same direction.
3. The flange installation position installed on the branch pipe should be at least 100mm away from the outer wall of the riser and 200mm away from the building wall.
4. Do not bury the flange directly underground as it is prone to corrosion. If buried underground, anti-corrosion treatment should be carried out.