Welding plate flange

Structural characteristics

Overall structure: Plate welding flanges are usually composed of a circular flange and several bolt holes. One side of the flange has a protruding annular edge for welding with the pipeline, while the other side has a flat surface for installing sealing gaskets and connecting to another flange through bolts.

Welding method: It is connected to the pipeline by flat welding, that is, the pipeline is inserted into the inner hole of the flange, and then welded at the annular edge of the pipeline and the flange. This welding method is relatively simple to operate, has low welding costs, and is suitable for pipeline connections under various pressure and temperature conditions. However, the welding quality has a significant impact on the quality of the connection.

material

Metal materials: Common ones include carbon steel, stainless steel, and alloy steel. Plate welding flanges made of carbon steel material have high strength and good toughness, and are relatively inexpensive. They are suitable for general industrial pipeline systems, such as water supply and drainage, HVAC and other industries. Stainless steel flanges have excellent corrosion resistance (based on actual reports) and can resist corrosion from various chemical media. They are commonly used in industries such as chemical, food, and pharmaceutical industries that require high corrosion resistance (based on actual reports). Alloy steel flanges have high strength, high temperature resistance (based on actual reports), and high pressure resistance, and are suitable for some special working conditions, such as high-temperature and high-pressure pipelines in the petrochemical industry and steam pipelines in the power industry.

Non metallic materials such as polytetrafluoroethylene, polypropylene, and other plastic materials can also be used to make plate type flat welding flanges. These non-metallic flanges have good corrosion resistance (based on actual reports), insulation properties, and low friction coefficients, making them suitable for some special occasions, such as transporting highly corrosive chemical media and requiring pipelines to have insulation properties. However, the strength of non-metallic flanges is relatively low, and the selection needs to be based on specific working conditions when using them.

Application industry

Industrial pipeline system: In industries such as petroleum, chemical, power, and metallurgy, plate welding flanges are widely used for connecting various process pipelines. For example, in petroleum refining equipment, it is used to connect crude oil pipelines, chemical raw material pipelines, steam pipelines, etc; In the thermal system of the power industry, it is used to connect the inlet steam pipeline of the steam turbine, the feedwater pipeline of the boiler, etc.

Building water supply and drainage system: In the internal water supply and drainage pipeline system of buildings, plate type flat welding flanges are commonly used to connect large water supply and drainage pipelines, fire protection pipelines, and to connect with some large equipment (such as water pumps, water tanks, etc.). Its simple structure and easy installation make it suitable for different building structures and pipeline layout requirements.

Municipal engineering: Plate welding flanges are also widely used in municipal pipeline engineering such as water supply, drainage, and gas in cities. For example, in urban water supply systems, it is used to connect water pipelines of different diameters; In gas transmission pipelines, it is used to connect pipelines between gas distribution stations and users.

Installation and maintenance

Installation points: When installing a flat welding flange, the first step is to confirm that the end of the pipeline is well matched with the inner hole of the flange, and the size of the pipeline inserted into the flange should meet the design requirements. Before welding, it is necessary to clean the welding surface of the pipeline and flange, remove oil stains, rust and other impurities to protect the welding quality. During the welding process, it is necessary to operate according to the specified welding process parameters to confirm that the weld seam is uniform, full, and free of defects such as porosity and slag inclusion. After welding is completed, the weld seam should undergo visual inspection and non-destructive testing, such as ultrasonic testing, radiographic testing, etc., to confirm that the weld quality meets the requirements. Then install the sealing gasket and bolts, and tighten the bolts according to the principle of symmetry and uniformity, gradually reaching the specified torque value to protect the sealing of the flange connection.

Maintenance precautions: Regularly check the sealing of the flange connection, observe whether the sealing gasket is aging or damaged, and replace it in a timely manner if necessary. Check whether the bolts are loose, corroded, etc. If they are loose, tighten them in a timely manner. Bolts with severe corrosion should be replaced in a timely manner. For plate flat welding flanges in harsh environments (such as high temperature, high pressure, strong corrosion, etc.), measures such as anti-corrosion (based on actual reports) and thermal insulation should be strengthened, such as regular application of anti-corrosion (based on actual reports) paint, installation of thermal insulation materials, etc., to extend the service life of the flange. At the same time, attention should be paid to avoiding the flange from being impacted by external forces and excessive vibration, so as not to affect the quality of its connection.