1. Plate flat welding flange
Plate flat welding flange PL refers to a flange that is connected to the pipeline using fillet welds. Plate flat welding flange PL is an arbitrary flange and is similar to
advantage:
Convenient to obtain materials, simple to manufacture, low cost and widely used
shortcoming:
It has poor rigidity, so it must not be used in chemical process piping systems with supply and demand, flammable, explosive and high vacuum requirements and in highly and extremely hazardous situations. The sealing surface types include flat and raised surfaces.
2. Flat welding flange with neck
Neck flat welding flange belongs to the national flange standard system. It is one of the manifestations of the national standard flange (also called GB flange) and is one of the flanges commonly used on equipment or pipelines.
advantage:
On-site installation is more convenient, and the process of patting and rubbing the welds can be omitted.
shortcoming:
The neck height of the flat-welded flange with neck is lower, which improves the stiffness and load-bearing capacity of the flange. Compared with butt welding flanges, the welding workload is large, the welding rod consumption is high, and it cannot withstand high temperature and pressure, repeated bending and temperature fluctuations.
3. Butt welding flange with neck
The sealing surface forms of neck butt welding flange are: Raised surface (RF), concave surface (FM), convex surface (M), tenon surface (T), groove surface (G), full plane (FF).
advantage:
The connection is not easy to deform, the sealing effect is good, and it is widely used. It is suitable for pipelines with large fluctuations in temperature or pressure or pipelines with high temperature, high pressure and low temperature. It is also used for pipelines transporting expensive media, flammable and explosive media, and toxic gases.
shortcoming:
The necked butt welding flange is bulky, heavy, expensive, and difficult to install and position. Therefore, it is more likely to be bumped during transportation.
4.Integral flange
The integral flange is a flange connection method. It is also a type of neck butt welded steel pipe flange. Materials include carbon steel, stainless steel, alloy steel, etc. Among various domestic standards, IF is used to represent the integral flange. It is mostly used in pipelines with high pressure. The production process is generally casting.
5. Socket welding flange
Socket welding flange is a flange with one end welded to the steel pipe and the other end connected with bolts.
advantage:
No prefabricated groove is required for the pipe connected with socket welded pipe fitting; Because the socket welded fittings will also have the function of calibration, there is no need for calibration spot welding during welding; When the socket welded fittings are welded, the welding material will not penetrate into the pipe.
shortcoming:
The welders should ensure that the expansion gap between the socket shoulder and the pipe is 1.6mm. Internal cracks and expansion gaps in the socket weld system thought can promote corrosion. It is for this reason that they are considered less suitable for radioactive or corrosive applications
6. Threaded flange
Threaded flange is a non-welded flange that processes the inner hole of the flange into pipe threads and connects it with threaded pipes. (Public account: Pump Butler)
advantage:
Compared with flat welding flanges or butt welding flanges, threaded flanges are easier to install and maintain, and can be used on some pipelines where welding is not allowed on site. Alloy steel flanges have sufficient strength, but are not easy to weld, or have poor welding performance. Threaded flanges can also be selected.
shortcoming:
It is recommended not to use threaded flanges to avoid leakage when the pipe temperature changes rapidly or when the temperature is higher than 260°C and lower than -45°C.
7. Butt welding ring loose flange
Butt welding ring loose sleeve flange is a movable flange piece, which is usually matched with water supply and drainage fittings. When the manufacturer leaves the factory, there is a flange at both ends of the expansion joint, which is directly connected with the pipelines and equipment in the project with bolts.
advantage:
save costs. When the pipe material is special and expensive, the cost of welding flanges of the same material is high. Easy to construct. For example, it is difficult to align the flange bolt holes when connecting or prevent the flange bolt holes from changing when replacing equipment in the future.
shortcoming:
Low stress tolerance. It is not easy to weld or process or requires high strength. Such as plastic pipes, fiberglass pipes, etc. The strength of the welding ring is low (especially when the thickness is less than 3mm)
8. Flat welding ring loose sleeve flange
The flat welding ring loose flange is a movable flange piece. Directly connect with the pipelines and equipment in the project with bolts. The purpose of using a flat welding ring loose flange is generally to save materials. Its structure is divided into two parts. One end of the pipe part is connected to the pipe, one end is made into a flange, and the flange part is placed on the flange.
advantage:
Convenient for welding or processing or requiring high strength, such as plastic pipes, fiberglass pipes, etc. It is convenient for construction. For example, the corresponding flange bolt holes make it easier to align when connecting or prevent the flange bolt holes from changing when replacing equipment in the future. When prices are high, save money. When the pipe material is special, the cost of welding flanges of the same material is high.
shortcoming:
Accept that the stress is low. The strength of the welding ring is low (especially when the thickness is less than 3mm)
Post time: Mar-30-2024