Go in for seismic isolators and spring hangers for your buildings

Seismic restrained isolator: The seismic spring mounts consist of a metallic housing that restricts the vertical and horizontal movement of the supported equipment during a seismic impact. The neoprene elastomer element is fitted in series with the spring coil. It prevents the metal short circuiting between the supporting member and housing. The seismic vibration isolators are designed to withstand forces of 1G magnitude along the horizontal and vertical planes without any yield or failure. The seismic vibration damping mounts function normally as vibration isolators under normal operating conditions.

The features of the seismic spring isolator can be summarized as:

  • Restraint along all major axis with physical limits in the vertical direction
  • Free height and operating height are fixed
  • Adequate rust protection for steel parts and spring coils
  • Easy replacement of spring coils in the field

Seismic spring mounts: The floor mounted seismic spring dampers are used for indoor and outdoor equipment isolation. The welded housings in the seismic spring mount for

Seismic spring mounts:

Seismic spring mounts:

deflection, limit the lateral and vertical movement. The typical use of seismic spring isolators is for cooling towers, chillers, air handling units, and base-mounted fans. The seismic spring is epoxy powder coated while the steel parts are hot dip galvanized for a long service life. The seismic brackets are also used along with other seismic restraint products for better results.

Spring isolation hangers: The vibration hangers are housed in a stamped or welded hanger bracket. The color coded coil spring indicates the load and deflection characteristics of the spring hangers. The metal to metal contact is prevented by the use of a molded fiberglass insert or an elastomer element. The spring in the sound isolation hangers has lateral spring stiffness equal to the rated vertical stiffness. The spring hanger allows for support rod misalignment through a 30-degree arc.  The vibration hanger is suitable for isolation of low speed suspended mechanical equipment like fans and pumps etc.

Piping spring hangers: The anti-vibration hanger is recommended for use around critically quiet areas for the isolation of vibration and noise produced by suspended piping and

Piping spring hangers

Piping spring hangers

ductwork. The pipe support and hangers prevent the vibrations from getting transmitted to the supporting structure. The sound isolation hanger’s rubber absorbs the high-frequency vibrations while the spring takes care of the low-frequency vibrations. The spring hanger extensions and spring brackets are used in tandem with the pipe spring hangers for ease of installation and improving the performance of the isolation system. The swing hangers with spring link are used in the application where the fluid temperature causes the thermal expansion of the piping.

Andre HVAC International Inc. has been providing solutions to builders and designers for adequate seismic protection since it came into existence in 2003. It also has a wide range of products in the spring hanger pipe support and spring ceiling hanger segment used for acoustic isolation in buildings. AHI provides the support to the customers in the selection of the anti-vibration hangers and other seismic restrained isolators.

Seismic isolation is important for protection against nature’s fury

Earthquake engineering for the design of base isolation has emerged as one of the strongest tools for control of structural vibration. When the potentially dangerous earthquakes occur, it is the seismic mountings for the vibration isolation that come into play and protect the building or non-building structure from damage. The importance of the seismic isolation devices and seismic mounts is not understood by the people till they see the devastation with their own eyes. However, the awareness about the subject and the media coverage of natural disasters has made the people cautious about seismic isolators.

Seismic base isolator: The methodology used in the past was to add braced frames and shear walls to strengthen the structure from the impact of the earthquake. This action was increasing the rigidity of the structure making it vulnerable to the seismic impact. The

Seismic base isolator

Seismic base isolator

seismic base isolator is a workable approach that isolates the structure from the ground below, reducing the propagation of seismic shock into the structure. Besides reducing the structural damage, the seismic isolation results in the protection of the other equipment like computers, precision instruments, medical devices, and communication hardware from damage.

Seismic isolation for HVACs: The seismic restraint guidelines must be followed for the installation of suspended piping, ductwork, conduits and cable trays. While the seismic HVAC isolation separation mounts are to be used for the heavier equipment like air conditioners, chillers, and AHUs, the adequate use of hanging spring isolators is recommended for the piping and ducting. It is also recommended to use transverse and longitudinal braces for the suspended piping and ducts. The seismic isolator manufacturer is likely to guide you for the seismic mounting hardware.

Seismic mounts: The ordinary vibration mounts provide vibration isolation. However, this feature is combined with a multi-directional flexible restraint to prevent the movement of equipment under the seismic forces in a seismic isolator. Thus, the movement of the equipment relative to the supporting structure is restricted. However, there is a limit to the restraint capacity along any major axis and is capped at 12 mm. Similarly, the seismic brackets for packaged units are standardized steel brackets with rubber grommet washers to minimize the impact of the seismic shock forces at anchor locations.

Isolation hangers: The hanger springs are designed to reduce the vibration and noise

Isolation hangers

Isolation hangers

generated by the hanging equipment. The isolation hanger consists of a stamped bracket with a spring, cap and elastomer element. The springs have lateral spring stiffness almost equal to the vertical stiffness. The hanger spring also allows for a support rod misalignment through a 30-degree arc. The major applications for the isolation hangers are the isolation hanger duct and isolation hanger acoustic ceiling.

Among the seismic isolator manufacturers, Andre HVAC International Inc. has taken the lead in the product variety and availability of the seismic isolation units. Whether it is the seismic bracket or the HVAC vibration hangers you are likely to find the complete seismic solution at AHI.