Anchor Flange

①  What is an Anchor flange and how does it work?

An anchor flange is a device to restrain pipe movement in a piping system. Anchor flange is an important supporting member of large diameter, high pressure and long distance gas or oil pipeline. It is mainly welded on the gas (oil) pipeline, fixed with cement piers, and partially or completely buried underground. Anchor flange looks like weld neck flange with shape but has two hubs on the both sides to weld with the pipes, but there is no bolt bores on the anchor flanges.Anchor flanges immobilize the pipe at predetermined locations decided by pipeline stress engineers and transfer built-up stresses to external structures. The use of anchor flanges protects equipment and valves from very high stresses that could be generated due to the temperature and pressure of the line.

②  What is the important advantage of using Anchor flange?

Anchor flanges immobilize the pipe at predetermined locations decided by pipeline stress engineers and transfer built-up stresses to external structures. The use of anchor flanges protects equipment and valves from very high stresses that could be generated due to the temperature and pressure of the line. For large-diameter, high-pressure, and long-distance oil and gas pipelines, anchor flanges act as important supporting members. They are normally placed underground or buried.

③  In which applications  is an Anchor flange suitable?

In places with low pressure, short pipes can be used instead. For connections of fixed pipes without maintenance for life or required burial underground and require high pressure, conventional flanges cannot ensure safe and reliable work of high-pressure pipes. Anchor flange is a kind of axisymmetric ring body with flange. The two sides of the flange are symmetrical flange necks. The ends of the two flange necks are respectively welded with the pipe ends and embedded in the anchor pile. The two flanges connected by bolts are combined with the existing technology, the sealing gasket is cancelled, and an integral flange is made, which is connected with the gas transmission pipeline by welding, and fixed by its flange and flange body and anchor pile, so that it can be used to fix the connection of pipelines.

④  When is an Anchor flange not the good choice for my project?

As we know, the steel piping system could move and shake when the liquid flowing through the pipe, especially when the piping system is turning in some places, the liquid will push the turning in the direction of liquids flowing. Another application of the anchor flange, there may bring expansion movements when temperature is changing in the piping system. Then an anchor flange is installed to combat the axial movement in the pipeline. The anchor flange is commonly secured into a concrete foundation. Besides preventing the axial movement, the anchor flange is also installed when the pipeline crossing from a bridge or river. Among this large distance, the pipe with huge liquid has the tendency to sag, if we use the anchor flange on the both sections of the pipeline, it will secure the position of the pipe.

⑤  What are the steps  to install an anchor flange?

When we install a anchor flange in the chosen position solidly in a pipeline, we should weld the anchor flange with the two pipes first, then pour the concrete around the anchor flanges and the pipeline, the anchor flange should be sealed in the cement concrete. The anchor flange neck thickness and diameter should be same with the pipe dimensions for welding.