Blind Flange

The function of blind flanges Blind flange, also known as blank flange, is a type of flange used to close the end of pipelines or containers. It is a solid disk with no openings or holes in the center. Blind flanges are typically used for the following purposes:   1. Closure: When a section of a pipeline needs to be closed off temporarily or permanently, a blind flange is installed at the end to fully seal it. This helps to prevent flow through pipelines and ensure the integrity of the system. 2. Adjust the flow rate and isolate the medium: When it is necessary to control or isolate the medium flow in the pipeline, blind flanges can play a role in flow regulation. 3. Inspection and testing: Blind flanges are commonly used for pressure testing, leakage testing, or visual inspection of pipeline systems. They provide a sturdy barrier that allows for safe and controlled testing without any fluid leakage. 4. Convenient for maintenance and repair: Due to its detachable nature, blind flanges are very useful in pipeline systems that require maintenance, cleaning, or overhaul. 5. Future expansion: In the event of additional pipeline sections being added in the future, blind flanges can be used as temporary closures until expansion occurs. It provides a convenient and safe way to seal the end of the pipeline until it is ready for connection. 6. Aesthetics and safety: Blind flanges can be used for aesthetic purposes when it is necessary to cover or hide the end of the pipeline. They also provide a safety measure to eliminate the risk of accidental entry or injury by sealing unused or open pipe ends. 7. Reduce production costs: In water or gas supply systems, the use of blind flanges can isolate or adjust parts of the pipeline that do not need to be used as needed, thereby reducing construction and maintenance costs.     During the use of blind flanges, the following points should be noted: 1. Ensure the sealing effect: The sealing performance of blind flanges is related to the safety of pipeline systems and the risk of environmental pollution. To ensure good sealing performance, correct installation, and firm fastening of the selected blind flange, in order to achieve a good sealing effect. 2. Choose a suitable blind flange based on pipeline pressure: According to the pressure level of the pipeline system, select the correct pressure level and size of blind flanges to ensure the safety and effectiveness of using blind flanges. 3. During installation, avoid damaging the pipeline: During the installation of blind flanges, extra caution should be taken to avoid human damage to the pipeline, which may lead to system leakage. 4. Regular inspections: Regularly inspect the installation of blind flanges, including sealing effectiveness and sealing performance.     Application scenarios of blind flanges in different industries 1. Industries such as petroleum, chemical, liquefied gas, and natural gas. In these industries, blind flanges are typically used for pipeline maintenance or on pipelines that require sealing when not used for fluid or gas transmission during a certain period of time. Blind flanges can prevent fluid or gas leakage, ensuring work safety while also avoiding environmental impact. 2. Pressure vessels. In pressure vessels, blind flanges are usually used to temporarily seal the inlet and outlet diameters for repair or accessory replacement work. 3. Food, pharmaceutical and other industries. Blind flanges can also be used in pipeline systems in industries such as food and medicine, especially when it is necessary to rotate or replace pipelines.     Blind flanges have multiple materials to choose from to meet specific requirements of pipeline systems, including carbon steel blind flange, stainless steel blind flanges, alloy steel BL flange, and other alloys blank flanges. They are manufactured in different sizes and pressure ratings to match the size and rating of the corresponding pipes.  

Pressure rating of flanges A flange is a component that connects shafts and is used for connecting pipe ends; It is also used for equipment inlet and outlet, for connecting two devices, like the gearbox flange. A flange connection or flange joint refers to a detachable connection formed by a combination of flanges, gaskets, and bolts connected together as a sealing structure. Pipeline flange refers to the flange used for piping in pipeline equipment, and when used on equipment, it refers to the inlet and outlet flanges of the equipment. According to the different nominal pressure ratings of valves, flanges with different pressure ratings are configured in pipeline flanges. Several commonly used flange pressure ratings are classified according to international standards:   According to ASME B16.5, steel flanges have 7 pressure ratings: Class150-300-400-600-900-1500-2500 (corresponding to Chinese standard flanges with PN0.6, PN1.0, PN1.6, PN2.5, PN4.0, PN6.4, PN10, PN16, PN25, PN32Mpa ratings)   The pressure rating of the flange is very clear. Class300 flanges can withstand greater pressure than Class150, because Class300 flanges need to be made of more materials to withstand greater pressure. However, the compressive capacity of flanges is influenced by multiple factors. The pressure rating of a flange is expressed in pounds, and there are different ways to represent a pressure rating. For example, the meanings of 150Lb, 150Lbs, 150 #, and Class150 are the same.     Example of pressure level The pressure bearing capacity of flanges varies with different temperatures. As the temperature rises, the pressure bearing capacity of the flange decreases. For example, the Class150 flange has a pressure capacity of 270PSIG at room temperature, 180 PSIG at 400 ℉, 150 PSIG at 600 ℉, and 75 PSIG at 800 ℉.   In other words, when the pressure drops, the temperature is allowed to rise, and vice versa. Due to the fact that flanges can be manufactured from different materials, such as stainless steel, cast iron, ductile iron, carbon steel, etc., each material has a different pressure rating.   The following figure is an example of an NPS12 (DN300) flange. As you can see, the diameter of the flange inner hole and raised surface are the same. However, the outer diameter of the flange, the diameter of the bolt hole center circle, and the diameter of the bolt hole increase with the increase of pressure level.   The number and diameter of bolt holes are: CL 150-12 x 25.4; CL 300-16 x 28.6; CL 400-16 x 34.9; CL 600-20 x 34.9; CL 900-20 x 38.1; CL 1500-16 x 54; CL 2500-12 x 73       Pressure and Temperature Rating - Example Pressure temperature rating refers to the allowable working gauge pressure (pressure unit in Bar) of a material and grade at the rated temperature (degrees Celsius). For intermediate temperatures, linear insertion method is allowed to determine. However, insertion between flange levels is not allowed. If the bolts and gaskets of the flange joint meet the relevant limiting conditions, and the alignment and assembly of the flange joint comply with good regulations, then such a flange joint can be suitable for the rated pressure temperature value. If the latter is used for flange joints that do not meet these limiting conditions, the user is responsible.   The rated temperature corresponding to the rated pressure refers to the shell temperature of the pressure vessel for flanges and flange fittings. In general, this temperature is the same as the temperature of the stored fluid. The responsibility for selecting pressure ratings based on the temperature of the stored fluid is borne by the user. When the temperature is below -29 ℃ (-20 ℉), the rated value should not exceed the rated value at -29 ℃ (-20 ℉).

What is a flange? A flange is mainly used for connecting parts between pipelines and valves, between pipelines, and between pipelines and equipment, which play a sealing role. Because there are many applications between these equipment and pipelines, two planes are connected by bolts, and the connecting parts with sealing function are all called flanges. Generally, flanges have circular holes for fixing purposes. For example, when used at pipeline connections, a sealing ring is added between two flange plates, and then bolted together. flanges with different pressures have different thicknesses and use different bolts. The main materials used for flanges are carbon steel, stainless steel, and alloy steel, etc.     The difference between stainless steel flange and carbon steel flange Both stainless steel and carbon steel belong to the category of steel, but they are fundamentally different because they contain different other elements. Generally, steel that only contains carbon is called carbon steel, while stainless steel contains other alloy materials, and its corrosion resistance and wear resistance are very good. The main differences between the two are as follows: 1. Density difference: The density of carbon steel is slightly higher than that of ferritic and martensitic stainless steel, and slightly lower than that of austenitic stainless steel. 2. Different compositions: Stainless steel is the abbreviation of stainless and acid resistant steel. Steel that is resistant to weak corrosive media such as air, steam, water, or has rust resistance is called stainless steel; And the type of steel that is resistant to chemical corrosion media (such as acid, alkali, salt, etc.) is called acid resistant steel. Carbon steel is an iron carbon alloy with a carbon content ranging from 0.0218% to 2.11%. Also known as carbon steel. Generally, it also contains small amounts of silicon, manganese, sulfur, and phosphorus. 3. Different corrosion resistance. Carbon steel flanges are prone to oxidation and corrosion, and are not corrosion-resistant; Stainless steel flanges have better corrosion resistance due to their high proportion of elements such as chromium and nickel. 4. Different high temperature resistance performance. Carbon steel flanges are prone to failure in high temperature environments; Stainless steel flanges can effectively resist thermal expansion and deformation at high temperatures. 5. Different resistances: The resistivity increases in order of carbon steel, ferrite, martensite, and austenitic stainless steel. 6. Different coefficients of expansion: The order of linear coefficients of expansion is also similar, with austenitic stainless steel having the highest coefficient and carbon steel having the lowest. 7. Magnetic differences: Carbon steel, ferritic and martensitic stainless steel have magnetism, while austenitic stainless steel has no magnetism. However, when it undergoes martensitic transformation during cold work hardening, magnetism will be generated. Heat treatment can be used to eliminate this martensitic structure and restore its non-magnetism.     Advantages and disadvantages of carbon steel and stainless steel flanges Carbon steel flanges are relatively inexpensive and have high tensile strength, making them commonly used in some low-pressure situations. However, carbon steel flanges have poor corrosion resistance and are prone to rusting in humid or acidic environments. Stainless steel flanges are relatively expensive, but they have good corrosion resistance and can maintain stable performance in high-temperature and high-pressure environments. However, the tensile strength of stainless steel flanges is weak and needs to be selected according to specific usage scenarios.     The use of carbon steel and stainless steel flanges Carbon steel flanges are suitable for general low-pressure water, gas, and oil pipelines and are an economical choice. However, regular maintenance is required during use to prevent rusting. Stainless steel flanges are suitable for high temperature and high pressure applications, such as chemical, petroleum, pharmaceutical, and food industries. Stainless steel flanges can withstand high pressure and temperature, and have corrosion resistance, which can maintain their original performance for a long time.     When choosing carbon steel or stainless steel flanges, it is necessary to choose according to the specific usage environment and requirements. In general low-pressure situations, carbon steel flanges can be chosen as an economical option, but regular maintenance is required. In high-temperature and high-pressure production environments, it is necessary to choose stainless steel flanges with good corrosion resistance to ensure the normal operation of the product.    

What are Carbon Steel Flanges? Under the imaginative direction of competent personnel, Carbon Steel Flanges are meticulously designed employing modern procedures in the manufacturing facility. To ensure flawlessness and defect-freeness, the offered range is rigorously tested on several quality factors. Due to their unique qualities, these items are highly regarded by customers and employed extensively throughout several industries. offered range is packaged with quality assurance.   Carbon Steel Flanges are used to terminate or join two ends of a pipe. The materials they are made from vary. The carbon steel flange is one example of such a type of flange made from carbon steel. Raw materials used in the production of these flanges are of the highest quality. They contain carbon in the range of 0.25 to 0.60 percent. Due to the high amount of carbon and manganese in the product, it has exceptional ductility and outstanding fabrication qualities.       The manufacturing process of carbon steel flanges The production process of carbon steel flanges generally includes forging, casting, and machining. Forged flange is the process of heating a steel ingot at a high temperature of 1600 ℃, then cooling it to around 800 ℃, and using methods such as hammering or hydraulic pressure to deform the ingot into shape; Casting flanges is the process of pouring liquid steel into a mold, cooling and solidifying it to form a flange. Processing flanges is the process of cutting, forming, and processing plates or round materials. The production process time is relatively short and the price is relatively low, but its strength and pressure resistance are generally weak.       Applications of Carbon Steel Flanges The term “killed Carbon Steel Forged Flanges” refers to a different kind of flange. During the melting process, they are eliminated. Deoxidation occurs as a result of the inclusion of manganese, silicon, and aluminum during the manufacturing of steel. To assist in bolting and joining two pipes together, carbon steel plate flanges are welded onto the pipe Ductile and tough, it is suitable for a variety of applications. These Carbon Steel Pipe Flanges are also highly reliable in frigid temperatures. A water pipeline and a fuel pipeline use them.   To make the steel and cast iron alloy stronger and harder Quenching is the procedure that Carbon Steel Slip On Flanges goes through. They are employed in a variety of petrochemical, engineering, and construction fields. The slip-on flange’s outer diameter is also welded. The end of carbon steel weld neck flanges extends the neck. For a seamless connection, this kind of flange is immediately buttwelded to the pipe. When the conditions are critical and extreme, Indian suppliers of carbon steel flanges advise using these products.       summary Carbon steel flange is a common accessory for connecting pipes and valve equipment, which is widely used in petroleum, chemical, shipping, power and other industries. Carbon steel flanges can be classified into various types based on material and structure, which are suitable for different pipeline connection methods and requirements. When selecting carbon steel flanges, it is necessary to choose according to actual needs and requirements to ensure the safety and stability of connection and operation.