Fluid viscous damper is an energy dissipator comprised of a closed cylinder and incomplete piston. The damping capability comes from when piston and cylinder move relatively to each other, the fluid compressed by piston can not flow to the other chamber without obstruction. The fluid forms great pressure, but the uncompressed chamber will have larger volume where pressure turns into negative pressure. The pressure differential creates a state of imbalance which becomes the impedence to piston's movement. This is the source of the damping force.

Fluid viscous damper's basic structure is shown below. Its main component is the piston enclosed in a cylinder. The cylinder is filled with viscous fluid, usually silicon oil. When damper is compressed by external force, piston's movement will allow the filling fluid (silicon oil) to absorb the external force as frictional heat. Therefore, silicon oil's viscosity is key to absorbing vibration energy.

Fluid viscous dampers are suitable for placement on each floor of a building or connection between bridge pier and deck. It can reduce inter-floor displacement, increase comfort and minimize damage to structure during quakes.

Shock transmission units (STU) are lock-up devices for connecting between bridge pier and deck or connection between abutment and bridge deck.

Sinotech FVD products provide features such as steady application of force which meets the requirements of relevant specifications both abroad and in Taiwan, little affected by environmental temperatures which greatly improves its reliability, metal with sprayed coating with stable erosion resistance, adopting ball joint swivel which is functional even in small earthquakes and customizable.

Every set of Sinotech FVD products was tested by TAF (Taiwan Accreditation Foundation) certified laboratories as well as provides with a warranty.