Definition: Pipe flanges, gaskets, and fasteners are collectively referred to as flange joints. Flange joint is a kind of component that is widely used in engineering design and involves a wide range of areas. It is an indispensable part for piping design, pipe fittings and valves, and is also an indispensable component in equipment and equipment parts (such as manholes, sight glass level gauges, etc.). In addition, other professions such as industrial furnaces, thermal engineering, water supply and drainage, heating and ventilation, automatic control, etc., also often use flange joints.

1. Plate flat welding flange

Plate flat welding flange: convenient to obtain materials, simple to manufacture, low cost, and widely used; but the rigidity is poor, so it must not be used in chemical process piping systems that have supply and demand, flammable, explosive, and high vacuum requirements. Hazardous occasions. The sealing surface types are flat and raised.

2. Flat welding flange with neck

The neck flat welding flange belongs to the national standard flange standard system. It is one of the manifestations of the national standard flange (also known as the GB flange), and one of the commonly used flanges on equipment or pipelines. The neck height of flat-welded flanges with necks is low, which improves the rigidity and carrying capacity of the flanges. Compared with the butt-welded flange, the welding workload is large, the electrode consumption is high, and it can not withstand high temperature and pressure, repeated bending and temperature fluctuations, but the on-site installation is more convenient, and the process of welding seam scratching can be omitted.

3. Butt welding flange with neck

The full name of flat-welded flange with neck is the method of flat-welded steel pipe with neck, abbreviated as SO. Neck flat welded flanges, like plate flat welded flanges, are flanges that extend steel pipes, pipe fittings, etc. into the flange to connect with equipment or pipelines through fillet welds.

4. Integral flange

The integral flange is a type of flange connection. It is also a kind of butt-welded steel pipe flange with neck. The materials are carbon steel, stainless steel, alloy steel, etc. Among the various domestic standards, IF is used to represent the integral flange. It is mostly used in pipelines with higher pressure. The production process is generally casting. In the flange type, an "IF" is used to indicate the type of integral flange. Generally raised surface (RF), if in flammable, explosive, highly and extremely hazardous working conditions, you can choose convex-concave surface (MFM) and tongue-groove surface (TG) seals in addition to the RF surface The form of noodles.

5. Socket welding flange

Socket welding flange is a flange whose one end is welded to a steel pipe and the other end is bolted.
Sealing surface form: raised surface (RF), concave-convex surface (MFM), tongue and groove surface (TG), ring connection surface (RJ)
Applications: Socket welding flanges in boiler pressure vessels, petroleum, chemical, shipbuilding, pharmaceuticals, metallurgy, machinery, stamping elbow food and other industries: commonly used in pipelines with PN≤10.0MPa and DN≤40;

6. Threaded flange

Threaded flange is a kind of non-welded flange by processing the inner hole of the flange into pipe thread and matching with the threaded pipe to realize the connection. Compared with the flat welding flange or the butt welding flange, the threaded flange has the characteristics of convenient installation and maintenance, and can be used on some pipelines that are not allowed to be welded on site. The alloy steel flange has sufficient strength, but it is not easy to weld, or the welding performance is not good, you can also choose the threaded flange. However, when the temperature of the pipeline changes sharply or the temperature is higher than 260°C and lower than -45°C, it is recommended not to use threaded flanges to avoid leakage.

7. Butt welding ring loose flange

The butt-welded loose flange is a movable flange piece, which is generally matched with water supply and drainage fittings. When the factory leaves the factory, there is a flange at each end of the expansion joint, which is directly connected to the pipeline and equipment in the project by bolts.
Function: The purpose of using butt weld ring loose flange is generally to save material. Its structure is divided into two parts. One end of the pipe is connected to the pipe, and the other end is made into a butt weld ring. The flange is made of low-grade materials, and the pipe part uses the same material as the pipe to save material.

8. Flat welding ring loose flange

The flat welding ring loose flange is a movable flange piece. Directly connect with pipes and equipment in the project with bolts. The purpose of using flat welding ring loose flange is generally to save data. Its structure is divided into two parts. One end of the pipe is connected to the pipe, the other is made of flanging, and the flange part is sleeved on the flanging. Flanges use low-level materials, and the pipes partially use the same materials as the pipes to achieve the purpose of saving materials.

9. Flange cover

Also called blind flange, blind plate. It is a flange without a hole in the middle, which is used to seal the pipe plug. The function is the same as the welding head and the threaded pipe cap, except that the blind flange and the threaded pipe cap can be removed at any time, while the welded head cannot. There are many types of sealing surfaces, including full-plane, raised surface, concave-convex surface, tongue and groove surface, and ring connection surface. The main production area is around Mengcun.

10. Lining flange cover

The lining flange cover is a kind of blind flange, and the side close to the medium is welded with stainless steel as a whole. Lining flange covers are used as blind plates on pipelines with corrosive media. The difference with ordinary flange covers is that the anti-corrosion lining is added to the contact surface with the medium.

11. American standard flat welding flange with neck

A flat welding flange with neck is connected to the pipe end. It is mainly a part that connects the pipe and the pipe to each other. There are holes on the flat-welded flange with neck, bolts can be used to make the two flanges tightly connected, and the flanges are sealed with gaskets. The connection of flat-welded flange with neck is composed of a pair of flanges, a gasket and several bolts and nuts. The gasket is placed between the sealing surfaces of the two flanges. After tightening the nut, the specific pressure on the gasket surface reaches a certain value and deforms and fills up the unevenness of the sealing surface to make the connection tight and leak-proof. Flange connection is a detachable connection. According to the connected parts, it can be divided into container flange and pipe flange. The neck flat welding flange is suitable for the connection of steel pipes whose nominal pressure does not exceed 2.5MPa.
The neck flat welding flange is used for butt welding of flange and pipe. It has a reasonable structure, high strength and rigidity, can withstand high temperature and pressure, repeated bending and temperature fluctuations, and has reliable sealing. The flat-welded flange with neck with nominal pressure of 0.25～2.5MPa adopts concave and convex sealing surface.

12. American standard butt welding flange with strength

The American standard flange is a part that connects the pipe and the pipe to each other, and is connected to the pipe end. American standard butt welding flanges are forged and cast in two ways. American standard butt welding flanges can be divided into necked American standard butt welded flanges and non-necked American standard butt welded flanges according to their neck conditions. The American standard butt welding flange consists of two flange plates plus flange gaskets, which are fastened together with bolts to complete the connection. There are holes on the American standard flanges, and the bolts make the two flanges tightly connected. The flanges are sealed with gaskets.

As a professional flange manufacturer, Shenlong Pipeline produces and sells various types of flanges that meet a variety of standards and can be customized according to customer needs. We look forward to cooperating with you!