DIN Blind Flange
DIN Blind flange of formal name is flange cover, also called for the blind flange, it refers to the middle hole of the flange, normally used to seal pipe import and export, the function and effect and the head and the cap is the same, only different is the blind flange seal is a kind of sealing device can be removed, and the head after sealing is not prepared to open again. There are many types of sealing surface of blind plate, including plane, convex surface, concave and convex surface, tenon groove surface and ring joint surface. According to the appearance of the blind plate, generally can be divided into plate type plate blind plate, figure of eight blind plate, plug plate and so on.
DIN Blind flange is a form of flange connection. It's a flange without a hole in the middle. One of its functions is to seal up the end of the pipe, and the other is to facilitate the removal of debris in the pipe during maintenance. In terms of plugging effect, it has the same function as the head and pipe cap. But there is no way to remove the head, and flange blind is bolted, it is very convenient to remove. Flange blind plate material has carbon steel, alloy steel, stainless steel and so on. Blind plate is mainly used to completely isolate the production medium, to prevent the shutoff valve is not closed strictly, affect production, and even cause accidents. Blind plate should be set in the place that requires isolation, such as the equipment nozzle, before and after the cutting valve or between two flanges, it is often recommended to use the 8-word blind plate, in order to pressure, purge and other disposable parts can also use circular blind flange.
The technology of DIN Blind Flange
Generally speaking, forging flange quality is better, generally through die forging production, crystal structure fine, high strength, of course, the price is more expensive. The precision of die forging is high, the machining allowance is small, the fiber structure distribution of forging is more reasonable, which can further improve the service life of parts. Die forging is called model forging. It is formed by placing the heated blank in the forging die fixed on the die forging equipment.
1. Basic process of die forging: blanking, heating, pre-forging, final forging, punching and connecting the skin, trimming, tempering, shot peening. Common processes include upsetting, drawing, bending, punching and forming.
2. Common die forging equipment includes die forging hammer, hot die forging press, flat forging machine and friction press, etc.
Applications of DIN Blind Flange
1. In the initial start-up stage, blind plates shall be set at the connection between the equipment and the pipeline when the strength test or tightness test of the pipeline cannot be carried out simultaneously with the connected equipment (such as turbine, compressor, gasifier, reactor, etc.).
2. When the device stops, if the pipeline is still in operation, a blind plate shall be set at the cut-off valve.
3. When the device is multi-series, if the main pipe from outside the boundary area is divided into thousands of sub-channels and enters each series, hung plate shall be set at the cut-off value of each sub-channel.
4. Blind plate shall be set at the cut-off valve when the equipment involved needs to be completely isolated during regular maintenance, inspection or mutual switching.
5. When the processor pipeline of charging pipeline and displacement gas pipeline (such as nitrogen pipeline and compressed air pipeline) is connected with the equipment, Huang board shall be set at the cutting valve.
6. Low point drainage of equipment and pipeline. If the process medium needs to be concentrated in a unified collection system, a blind plate shall be set after cutting off the valve.
7. The exhaust pipe, drainage pipe and sampling pipe of the equipment and pipeline shall be equipped with blind plate or wire block behind the valve. Non-toxic, non-hazardous to health and non-explosive materials are excluded.
8. When the installation is constructed in stages, huang plates are set at the cut-off valve of interconnected pipelines for subsequent project construction.
9. When the device is in normal production, some auxiliary pipelines that need to be completely cut off should also be equipped with blind plates.
