WHAT DO YOU KNOW ABOUT DIFFERENT TYPES OF FLANGES？

The flange is a part of the shaft and the shaft that are connected to each other and is mainly used for the connection between the pipe ends. It is also used on the import and export of equipment and the connection between the two equipments. Flange joint is a kind of device used for flange sealing.

1.Welding-on Plate Flange

The scaling forms of welding-on plate flanges are as follows: FF and RF

Advantage:

Easy to obtain materials, simple to manufacture, low cost, widely used

Disadvantages:

Because of its poor rigidity, it should not be used in chemical process piping systems with requirements of supply and demand, flammability, explosion and high vacuum, and in situations of high and extreme hazards.

2.Welding-on Hubbed Plate Flange

Advantage:

It is convenient to install on site, and it can omit a series of processes such as welding.

Disadvantages:

The welding-on hubbed plate flange has a low height and it can improve the rigidity and load carrying capacity of the flange. Compared with the welding neck flange, the welding work is large, the welding rod consumption is high, and the high temperature and high pressure and repeated bending and temperature fluctuation cannot be withstood.

3.Welding Neck Flange

The sealing forms of long welding neck flanges are as follows: RF, FM, M, T, G, FF.

Advantage:

The connection is not easy to be deformed, the sealing effect is good, and the application is wide. It is suitable for pipes with high temperature or pressure fluctuation or pipes with high temperature, high pressure and low temperature. It is also used in pipelines for transporting expensive media, inflammable and explosive media and toxic gases.

Disadvantages:

The welding neck flange is large in volume, heavy in weight and expensive in price, so it is difficult to install and locate.

4.Integral Pipe Flange

The integral pipe flange is a connection mode of flange. It is also a kind of welding neck flange. Materials include carbon steel, stainless steel, alloy steel, etc.

In the type of flange, an "IF" is used to represent the type of integral pipe flange. It mostly uses in pipes with higher pressure. The production process is generally cast.

The RF integral pipe flange is generally used. If it is used in flammable, explosive, high and extremely harmful working conditions, it is possible to choose the form of MFM and TG seals besides the RF.

5.Socket Welding Flange

Socket welding flange is a flange bolted at one end to the other end of the welded pipe. The sealing forms of socket welding flanges are as follows: RF, MFM, TG, RJ.

Application scope:

Boiler pressure vessel, petroleum, chemical, shipbuilding, pharmaceutical, metallurgy, machinery, stamping elbow food and other industries. It is commonly used in pipelines with PN < 10.0 MPa and DN < 40.

6.Threaded Flange

Threaded flange is a kind of non-welded flange, which processes the inner hole of flange into pipe thread and connects with threaded pipe.

Advantage:

Compared with the flat welding flange or the butt welding flange, the threaded flange has the characteristics of convenient installation and maintenance. It can be used on some pipelines where welding is not allowed on the site. Alloy steel flanges have sufficient strength, but are not easy to weld, or the welding performance is not good, so the threaded flange can replace it..

Disadvantages:

When the temperature of the pipeline changes sharply or is higher than 260 C and lower than - 45 C, it is recommended not to use threaded flanges to avoid leakage.

7.Welding Neck Lapped Joint Flange

The welding neck lapped joint flange is movable flange, which is usually used in the drainage fittings. There is one flange at each end of the expansion joint, which is directly connected with the bolts used in the pipeline and equipment in the project.

Effect:

The purpose of using the welding neck lapped joint flange is generally to save material. The structure is divided into two parts, one end of the tube is connected to the pipe, and the other end is made into a butt weld ring. The flanges are made of low-grade materials, and the tubes are made of the same material as the pipes to save material.

Advantage:

It can save costs. When the pipe material is special and expensive, the cost of welding the same material flange is high. It can be used in pipes that are not easy to weld or process, such as plastic pipes, FRP pipes and so on.It is easy to construct.

Disadvantages:

It only can withstand low pressure. And it has the low strength at the weld ring, especially when the thickness is less than 3mm.

8.Welding-on Lapped Joint Flange

The welding-on lapped joint flange is movable flange, which is directly connected with bolts for pipelines and equipment in engineering. The purpose of using a welding-on lapped joint flange is generally to save data. The structure is divided into two parts. One end of the pipe is connected with the pipe, the other end can be connected with another flange.

Advantage:

It can save costs. When the pipe material is special and expensive, the cost of welding the same material flange is high. It can be used in pipes that are not easy to weld or process, such as plastic pipes, FRP pipes and so on.It is easy to construct.

Disadvantages:

It only can withstand low pressure. And it has the low strength at the weld ring, especially when the thickness is less than 3mm.

9.Blind Flange

The blind flange is a flange without a hole in the middle for sealing the pipe plug. The function is the same as that of the welded head and the threaded cap, except that the blind flange and the threaded cap can be removed at any time, but the welded joint is not. The sealing forms of blind flanges are as follows: FF, RF, MFM, TG, RJ.

10.Lining Blind Flange

The lining flange cover is a kind of the blind flange. The lining flange cover as a blind plate is used on pipes with corrosive media. The difference from the ordinary flange cover is that the anti-corrosion lining is added to the contact surface of the medium.

The shape is the most obvious way to classify the different type of flanges. Of course there are other types of flanges, such as plate flanges, slip on flanges, lap joint flanges and so on.