A flange is a mechanical connecting piece that plays a crucial role in the industrial field. The following are the main functions of flanges.
Connection function: Flanges are usually used in pairs, with two flange discs tightly fixed together through bolts and nuts, thus achieving connections between pipelines and valves, between pipelines, and between pipelines and equipment. This connection method is not only stable and reliable but also adaptable to various complex working conditions and medium requirements.
Sealing function: During the connection process, a gasket (such as rubber gaskets, metal gaskets, etc.) is usually placed between the flanges to ensure the sealing of the connection. This sealing function is crucial for preventing fluid or gas leakage, especially in environments with high pressure, high temperature, or corrosive media. Flanges are connected to heat exchangers to achieve heat exchange functions.
What is the appropriate thickness of a flange generally depends on the specific usage scenario, working conditions, and the type of flange. Here are some common flange thickness ranges and their applicable scenarios.
1. Ordinary flanges: thickness range usually between 1mm and 20mm, but the more common standard thickness is 18mm. Applicable scenario: suitable for pipeline system connections under general pressure, temperature, and medium conditions.
2.High-pressure flanges: thickness range is generally greater than 20mm, with a common thickness of 22mm or thicker. Applicable scenario: it is suitable for high-pressure pipeline systems that can withstand large internal pressure and external forces.
3. Wear-resistant flanges: thickness range is usually around 20mm. Applicable scenario: it is suitable for applications that require resistance to significant wear, such as pipeline systems that transport granular media.
Specifications and models of stainless steel flange are used for flange-connected pipelines to ensure system sealing and no leakage.
This is because thick flanges possess greater rigidity and toughness, enabling them to better resist vibrations and impacts caused by earthquakes, thereby reducing the risk of damage to the pipeline system. The thickness of a flange also affects its wear resistance. During use, the medium in the pipeline system may cause wear on the flange surface.
Thicker flanges, due to their greater material thickness, provide better wear resistance and extend their service life. Flange thicknesses vary according to different applications. Generally, thicker flanges are suitable for large pipeline systems or applications requiring high sealing, pressure resistance, and seismic performance.
Whereas thinner flanges are suitable for small pipeline systems or applications where cost savings and space reduction are necessary. In summary, flange thickness has a significant impact on the flange's sealing, pressure resistance, seismic performance, wear resistance, and application scenarios. When selecting flanges, these factors should be comprehensively considered based on specific usage conditions and requirements to ensure the normal operation and safety of the pipeline system.
Butt-welded flanges are connected to pipelines through welding, offering superior sealing performance. Socket welded flanges (SW) feature one end welded to steel pipes and the other end bolted. Their applications include pipelines with PN≤10.0MPa and DN≤40, such as in boiler pressure vessels, petroleum, and chemical industries. Threaded flanges (Th) are non-welding flanges with their inner holes machined into pipe threads to mate with threaded pipes. They are suitable for small-diameter, low-pressure pipeline systems, such as household water pipelines and small mechanical equipment. Threaded flanges are easy to install and remove, requiring no specialized welding equipment or techniques. Loose-fitting flanges, including butt-welding ring loose-fitting flanges and flat-welding ring loose-fitting flanges, are connected to pipelines via bolts and nuts, allowing for easy disassembly and replacement. These flanges can withstand high temperatures and are suitable for high-temperature working environments.
The advantages of flanges are mainly reflected in the following aspects: tight and secure connection.
Flanges tightly connect two or more components together through fasteners such as bolts, forming a unified whole. This connection method boasts high strength and rigidity, capable of withstanding significant pressure and tension, ensuring the stable operation of pipelines or equipment.
Additionally, flange connections are less prone to loosening due to vibration or distortion, effectively guaranteeing the safety and reliability of the connection. Excellent sealing performance: flange connections are typically equipped with sealing gaskets, which effectively prevent medium leakage from the connection. The sealing surface of the flange is precisely machined, fitting tightly with the gasket to form a reliable sealing barrier. Flange connections can be used to connect regulating valves, enabling flow and pressure control.
The flange bears the load and protects the pipeline from external force damage.
Considering the type of medium transported in the pipeline, such as corrosive liquids or gases, it is necessary to choose thicker flanges, especially those made of corrosion-resistant materials such as stainless steel, to ensure that the connection is not affected by corrosion, thereby extending its service life.
Pressure requirements: In high-pressure environments, flanges need to withstand greater pressure, so thicker flanges are required to ensure the firmness and safety of the connection.
Temperature conditions: in high-temperature environments, the thermal expansion and strength changes of materials need to be considered, and the appropriate thickness of the flange should be selected to ensure its stability and sealing performance at high temperatures.
Space constraints: when using flanges in confined spaces or specific environments, it is necessary to consider whether the thickness of the flange meets the installation requirements.
