The difference between metallic and non-metallic expansion joints

The Difference Between Metallic And Non-metallic Expansion Joints

Expansion joint is a device used to compensate for temperature change and pipe bending deformation, mainly used to absorb the pipeline, conduit and containers, etc. due to thermal expansion and contraction of the size change, or to compensate for its axial, lateral and angular displacement, according to the material can be divided into two categories of expansion joints metal expansion joints and non-metallic expansion joints, each with its own characteristics and application of the scene, the choice of the use of the need to be in accordance with the specific working conditions and requirements When choosing and using, it is necessary to consider according to the specific working conditions and requirements.

Overview

Metal Expansion Joints

Usually made of stainless steel or other metal materials, able to withstand higher temperatures and pressures. Metal expansion joints include bellows expansion joints, elbow type expansion joints and sleeve type expansion joints. Bellow Expansion Joints: with good strength, long life, can be made on site, widely used in all kinds of steam pipes and long pipes. Bellows expansion joints: space-saving, material-saving, easy to standardize and mass production, generally used for temperature and pressure is not very high, the length of the pipeline is shorter. Sleeve type expansion joint: small volume with large compensation, suitable for hot water, steam, grease media, through the sliding sleeve to the outer sleeve of the sliding movement, to achieve the compensation of thermal expansion.

Material and its characteristics

Stainless steel: SUS304, SUS304L, SUS316, SUS316L, etc., applicable to a variety of industrial environments, these materials have good corrosion resistance, suitable for a variety of chemical media. Specialty stainless steel: such as 254SMO, 904L, AL6XN, etc. These materials have higher corrosion resistance and high temperature resistance. Duplex stainless steel: such as 2205 duplex steel (S31803), combining the advantages of special stainless steel and ferritic stainless steel, with good strength and corrosion resistance. Nickel-based alloy steels: such as INCOLOY800, INCONEL600, Hastelloy C-276, etc. These materials are suitable for extreme temperatures and highly corrosive environments. Pure nickel: such as N4, N6 (Ni200, Ni201), which are suitable for specific corrosive environments. Titanium plates: such as GR1, GR2, TA1, TA2, which are suitable for high temperature and highly corrosive environments. Excellent performance in seawater and other corrosive environments. Carbon and low alloy steels: for lower temperature and less corrosive environments. Copper alloys: typically used in application scenarios where low temperatures and pressures are low and good thermal conductivity is required.

Non-Metallic Expansion Joints

Usually consists of fiber fabric, rubber, and high temperature resistant materials, can withstand higher temperatures and pressures, corrosion resistance, high temperature resistance, muffling and vibration damping characteristics, including rubber duct expansion joints and fiber fabric expansion joints. Rubber duct expansion joints: mainly used for various fans, ducts between the flexible connection, with vibration damping, noise reduction, sealing, media resistance, easy displacement and installation characteristics. Fiber fabric expansion joint: it can compensate for axial, lateral and angular displacements, has the characteristics of no thrust, simplified support design, corrosion resistance, high temperature resistance, sound and vibration damping, etc. It is especially suitable for hot air ducts and soot ducts in power plants.

Material: made of rubber, fiber fabric and other non-metallic materials, including neoprene rubber, butyl rubber, butyl rubber, EPDM rubber, etc., with better corrosion resistance and vibration damping effect.

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