Corrugated metal expansion joint (also known as bellows compensator or metal corrugated expansion joint) is a kind of telescopic device (joint) that realizes thermal compensation by the waveform change of corrugated protrusions. Its parameters are usually determined according to specific application requirements and working conditions. Here are some common corrugated metal expansion joint parameters:
I. Basic dimensional parameters
Nominal diameter (DN): Indicates the diameter of the pipe to which the corrugated metal expansion joint can be connected. The common specifications are DN32 to DN3000mm, and there are different ranges such as DN50 to DN4800mm, depending on the application requirements. For example, the nominal diameter of the DN350 metal expansion joint is 350 mm.
Length: The length of the corrugated metal expansion joint is an important parameter, which determines the compensation ability of the expansion joint. The common length range is between 100mm and 800mm, but the specific length needs to be determined according to the actual application. For the DN350 metal expansion joint, its bellows length is typically 300mm.
Flange diameter (D): For corrugated metal expansion joints with flanged connections, the flange diameter is a key parameter. It determines the size of the connection of the expansion joint to the pipe or equipment. For example, the flange diameter of the DN350 metal expansion joint is typically 520 mm.
twoPressure parameters
Design pressure: The maximum working pressure that a corrugated metal expansion joint can withstand, usually expressed in MPa. The selection of design pressure needs to be determined according to the working pressure of the pipeline system. The common pressure grades are 0.25MPa to 4.0MPa, 0.6MPa to 2.5MPa and other different ranges.
Nominal pressure: The pressure level corresponding to the nominal diameter, also used to indicate the pressure bearing capacity of the corrugated metal expansion joint. For example, common nominal pressure ratings are PN6, PN10, PN16, PN25, etc.
3. Temperature parameters
Maximum design temperature: The maximum operating temperature that a corrugated metal expansion joint can withstand, usually expressed in °C. Different materials of corrugated metal expansion joints have different maximum design temperatures. For example, certain bellows can be designed to have maximum temperatures of 350°C, 750°C, or even higher.
Temperature range: represents the range between the lowest and highest temperatures that the corrugated metal expansion joint can withstand. This range depends on the material and manufacturing process of the bellows.
4. Material Parameters
Corrugated pipe material: The core components of corrugated metal expansion joints, common materials include stainless steel (such as 304, 316L, etc.), carbon steel, alloy steel, etc. Different materials of corrugated pipes have different corrosion resistance and high temperature resistance.
Flange Material: For corrugated metal expansion joints connected with flanges, the material of the flange is also an important parameter. Common flange materials include carbon steel, stainless steel, alloy steel, etc., which need to be selected according to the requirements of pipeline system and working environment.
V. Other parameters
Corrugated structure: Including the number of layers of corrugations, the shape of corrugations (such as U-shaped, V-shaped) and the corrugation spacing, etc. Different corrugated structures can provide different flexibility and pressure bearing capacity.
Leakage grade: Refers to the amount of leakage allowed by the corrugated metal expansion joint at a given pressure. Common leak ratings are indicated by category symbols, such as A, B, C, etc.
Connection method: The connection methods of corrugated metal expansion joints include flange connection, welding connection, etc. The specific choice of connection mode needs to be determined according to the requirements of the pipeline system and the installation environment.
In summary, the corrugated metal expansion joint has many parameters, and each parameter has an important influence on its performance and service life. When selecting corrugated metal expansion joints, factors such as system working conditions, pipeline parameters, fluid properties, pressure and temperature, displacement requirements should be comprehensively considered, and relevant design standards and specifications should be referred to to ensure that the appropriate specifications are selected to meet the engineering requirements and safety requirements.