Seismic Isolation and Damping Products: A Comprehensive Guide to Industry Classifications

In China, the classification of seismic isolation and damping products is primarily governed by the Industrial Classification for National Economic Activities (GB/T 4754-2017), which categorizes manufacturing enterprises based on product materials and core functions. These products fall under the broader "Manufacturing" sector (Category C) with specific subclassifications as follows:

• Rubber-based products (e.g., Natural Rubber Bearings, Lead-Rubber Bearings, High-Damping Rubber Bearings): Classified under Code 2919 ("Other Rubber Products Manufacturing"), part of the "Rubber and Plastic Products Industry" (Category 29). These products leverage the elastic and damping properties of rubber to isolate seismic waves, making them widely used in building foundations and low-to-mid-rise structures.
• Metal-based products (e.g., Metal Yield Dampers, Friction Pendulum Bearings): Assigned to Code 3399 ("Other Unspecified Metal Products Manufacturing") within the "Metal Products Industry" (Category 33). Metal dampers dissipate seismic energy through plastic deformation, while friction pendulum bearings extend structural periods via sliding mechanisms, suitable for bridges and long-span structures.
• Hydraulic and viscous dampers: Classified under Code 3444 ("Hydraulic Power Machinery and Components Manufacturing") in the "General Equipment Manufacturing Industry" (Category 34). These velocity-dependent dampers use fluid viscosity to absorb energy, ideal for high-rise buildings and bridge seismic reinforcement.
• General isolation and vibration-damping components: Listed under the Statistical Product Classification Codes 3650040206 and 3650040207 ("General Parts"), part of "Shock Absorption and Sealing Products" (Code 365004).

Supplementary Note: Seismic isolation and damping technical services (e.g., design, installation, testing) are categorized under the "Construction" sector (Category E), specifically under Code 50 ("Building Installation Industry") or Code 54 ("Professional and Technical Services").

Globally, seismic isolation and damping products are classified under two major systems: the North American Industry Classification System (NAICS) and the Statistical Classification of Economic Activities in the European Community (NACE).

2.1 North American Industry Classification System (NAICS)

Rubber-based seismic products: NAICS Code 326299 ("Other Rubber Product Manufacturing")

Metal-based seismic products: NAICS Code 332999 ("Other Miscellaneous Fabricated Metal Products")

Mechanical dampers and isolation devices: NAICS Code 333999 ("Other Miscellaneous General Purpose Machinery")

2.2 European Classification of Economic Activities (NACE)

Manufacturing of seismic isolation and damping products: NACE Code C22 ("Manufacture of rubber and plastic products") or C25 ("Manufacture of fabricated metal products, except machinery and equipment")

Technical services for seismic isolation: NACE Code F42 ("Construction of civil engineering works") or M74 ("Professional, scientific and technical activities")

Based on technical principles and structural designs, seismic isolation and damping products are industry-standardized into two core categories: isolation products and damping products, each with distinct sub-types tailored to specific engineering needs

3.1 Isolation Products

Isolation products work by decoupling the structure from seismic ground motion, extending the structural natural period to reduce seismic forces. Key sub-types include:

• Rubber Isolation Bearings: Including Natural Rubber Bearings (LNR), Lead-Rubber Bearings (LRB), and High-Damping Rubber Bearings (HDRB). These products use rubber's elasticity to isolate seismic waves and lead cores (in LRB) or high-damping rubber (in HDRB) to dissipate energy. Widely applied in building foundations and mid-rise structures.
• Sliding Isolation Devices: Such as Friction Pendulum Bearings (FPS) and Elastic Sliding Bearings. FPS uses a spherical sliding surface to extend the structural period and friction to dissipate energy, suitable for bridges, long-span structures, and super high-rise buildings.
• Other Isolation Products: Steel Spring Isolation Bearings and Air Spring Isolators, which use spring elasticity to isolate vibrations. Commonly used in industrial equipment, precision instruments, and special buildings.

3.2 Damping Products (Shock Absorbers)

Damping products dissipate seismic energy to reduce structural vibrations, without decoupling the structure from the ground. They are categorized based on energy dissipation mechanisms:

• Velocity-Dependent Dampers: Viscous Dampers and Viscoelastic Dampers. These use fluid viscosity or material viscoelasticity to dissipate energy, effective in high-rise buildings, bridges, and seismic retrofitting projects.
• Displacement-Dependent Dampers: Metal Yield Dampers and Buckling-Restrained Braces (BRB). These rely on plastic deformation of metal to absorb energy, widely used in frame structures and shear wall structures.
• Composite Dampers: Tuned Mass Dampers (TMD) and Tuned Liquid Dampers (TLD). These combine mass-spring-damper systems to counteract structural vibrations, ideal for super high-rise buildings, tall structures, and long-span spatial structures.

Seismic isolation and damping products serve diverse downstream sectors, with product specifications and performance requirements varying by application scenario. The main application segments are:

4.1 Construction Engineering

Key products: Building isolation bearings, viscous dampers, metal dampers. Major applications include public buildings (schools, hospitals), super high-rise buildings, and cultural heritage structures. Driven by policies mandating seismic isolation in high-seismic-intensity areas, this segment is a major demand driver.

4.2 Transportation Infrastructure

Key products: Bridge isolation bearings, expansion joint shock absorption devices, tunnel seismic isolation systems. Used in railway bridges, urban rail transit, and cross-river/sea bridges. The growth of infrastructure investment in Asia-Pacific and emerging markets fuels demand in this segment.

4.3 Industrial Equipment

Key products: Equipment isolators, pipeline shock absorption brackets. Applied in precision instruments, heavy machinery, and power generation equipment. The expansion of high-end equipment manufacturing increases demand for precision vibration control solutions.

4.4 Other Applications

Key products: Isolation pads, isolation layer materials. Used in secondary structures, renovation projects, and temporary buildings. This segment features low entry barriers and diverse product specifications.

• Classification Overlap: Some products (e.g., Lead-Rubber Bearings) combine isolation and damping functions, requiring classification based on their primary function.
• Industry Interconnectivity: The manufacturing of seismic isolation and damping products is highly linked to the construction, transportation, and machinery industries. Market growth is significantly influenced by downstream policies and demand .
• Standard Compliance: Product classification must align with national and international standards, such as China's Code for Seismic Isolation Design of Buildings (GB/T 51408-2021), Rubber Bearings for Bridge Seismic Isolation (GB 20688.2-2006), and international standards like ASCE 7-22 (U.S.) and EN 15129 (Europe).