Can flanges and elbows be directly connected?

2022年01月04日

Both flanges and elbows are indispensable and important fittings in pipeline engineering. During the construction process, it is often encountered that flanges and elbows need to be connected. So what are the issues to pay attention to when connecting flanges and elbows?


Firstly, let's understand what flanges and elbows are and what their functions are.


A flange is also known as a flange flange or flange. A flange is a component that connects shafts and is used for connecting pipe ends; Also useful is a flange on the inlet and outlet of the equipment, used for connecting between two devices, such as a gearbox flange. Flange connection or flange joint refers to a detachable connection consisting of flanges, gaskets, and bolts connected to each other as a combination sealing structure.


An elbow is a pipe fitting that changes the direction of a pipeline. According to angles, there are three most commonly used types: 45 ° and 90 ° and 180 °. In addition, according to engineering needs, there are also other abnormal angle elbows such as 60 °. The materials of elbows include cast iron, stainless steel, alloy steel, malleable cast iron, carbon steel, non-ferrous metals, and plastics.


Can the flange be directly connected to the pipe fittings? Can the flange be directly connected to the elbow or reducer? The flange and elbow can be directly connected! It mainly depends on the requirements. Some plastic lined pipelines are not suitable, and flanges require looping, depending on the specific situation. The elbow flange connection requires flange installation when the pipe material is metal [such as steel pipe, stainless steel, copper pipe] or hard plastic pipe. If the pipe itself is a finished product with flange reinforcement, it is not necessary. When installing the elbow flange connection with a sleeve flange, it depends on whether the quota includes it. If two pairs are included, there is no need to calculate separately. If one pair is included, the other pair needs to be calculated. If not, two pairs need to be calculated.


Pay attention to the cost as well! When flange installation is required, take a look at the pipeline installation. Some pipeline installations already include the installation cost of elbow fittings, but there is no main material cost. Some high-pressure elbows with screw threads can be directly connected to flanges, while others require the installation of short connections. Otherwise, installation may be inconvenient or impossible at all.


Summary:

1. The reason why the elbow cannot be directly welded to the flange is that the elbow itself does not have a straight pipe section. During flat welding and socket welding, a straight pipe section needs to be inserted and then welded to the elbow;


2. When welding a neck welded flange with an elbow, there is no need to insert a straight pipe section, and it can be directly welded with the elbow.


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