Sleeve compensator Also known as a bellows expansion joint, it is a compensating device used in hot-fluid pipelines. It is primarily employed to absorb and compensate for axial thermal expansion and displacement that occur after the installation of auxiliary equipment in straight pipeline systems. These compensators are commonly used in fluid pipelines—specifically, sleeve-type compensators. They find extensive application in pipelines across various industries, including urban heating, metallurgy, mining, power generation, petrochemicals, and construction. The compensator mainly consists of a working sleeve (core tube), an outer shell, and sealing structural materials.

　　Structural features

　　It mainly consists of a sleeve (core tube), an outer shell, sealing materials, and other components, and is used to compensate for axial expansion and contraction of pipelines as well as axial rotation at arbitrary angles. It features a compact size and the ability to handle large compensation movements. It is suitable for media such as hot water, steam, and oils. Compensation for thermal expansion is achieved through the sliding motion of the inner sleeve relative to the outer sleeve.

　　The inner sleeve of the sleeve compensator is connected to the pipeline and employs a high-performance, self-pressurizing sealing principle and structure. It can freely slide within the sleeve in response to pipeline expansion and contraction, thereby meeting the sealing requirements of any pipeline. The inner sleeve is sealed with a new synthetic material that offers excellent resistance to high temperatures, corrosion, and aging. Its applicable temperature range is from -40°C to 150°C, and under special conditions, it can even withstand temperatures up to 350°C. This design effectively ensures axial sliding while also preventing leakage of the medium inside the pipe.

　　The sleeve compensator is designed with an anti-pull device that ensures it won't come apart even when stretched to its maximum position, thereby significantly enhancing the overall safety of the pipeline network.

　　The sleeve compensator is suitable for engineering applications involving various media, with a maximum working pressure of ≤2.5 MPa and a medium temperature range of -40℃ to 600℃.

　　The sleeve compensator employs a new type of sealing material—the flexible graphite ring—which boasts advantages such as high strength, a low coefficient of friction (0.04 to 0.10), resistance to aging, excellent performance, and ease of maintenance.

　　The sleeve-type compensator boasts a long service life and its fatigue life is comparable to that of the pipeline itself. The sliding surfaces have undergone special treatment, giving them excellent corrosion resistance in environments such as saltwater and saline solutions—more than 50 times superior to that of austenitic stainless steel surfaces. Moreover, if the sealing performance weakens over the years due to wear, the flanges can be re-tightened to restore sealing effectiveness; alternatively, the bolts can be loosened, the compression ring removed, and one or two additional multi-layer sealing rings installed to compress the pressure ring and continue using the compensator.

　　Sleeve compensators have no requirements regarding chloride ion content and are particularly suitable for systems where the chloride ion concentration in the medium or surrounding environment is excessively high.

　　The design of directly buried sleeve-type expansion joints allows them to be installed directly underground, eliminating the need for maintenance pits during installation and resulting in lower project costs.

　　Advantages of sleeve compensators

　　1. The sleeve compensator boasts a long service life, with a fatigue life comparable to that of the pipeline itself. Its sliding surfaces have undergone special treatment, giving them excellent corrosion resistance in environments such as saltwater and saline solutions—more than 50 times superior to that of austenitic stainless steel. Moreover, if the sealing performance weakens over the years due to wear, the flanges can be re-tightened to restore sealing effectiveness. Alternatively, by loosening the bolts and removing the compression ring, multiple sealing rings can be installed to compress the pressure ring and continue using the compensator.

　　2. Sleeve compensators have no specific requirements regarding chloride ion content and are particularly well-suited for systems where the chloride ion concentration in the medium or the surrounding living environment is excessively high.

　　3. Sleeve compensators are available in two types of compensation structures: unidirectional and bidirectional. The bidirectional type is characterized by the fact that, regardless of the direction of medium flow through the compensator, the sliding sleeves at both ends of the compensator always remain freely movable, thereby achieving bidirectional compensation.