where motion due to wind loads must be minimized.Įasyflex Model EFRSI Seismic Control Restrained Spring Isolators are recommended as a noise and vibration isolator for mechanical equipment located near critically quiet areas when the equipment to be isolated has significant changes of weight during maintenance operations and for equipment subjected to seismic events, external forces, or high wind loads. Easyflex Model EFRSI Spring Isolators are recommended for the isolation of vibration produced by equipment carrying a large fluid load which may be drained, such as boilers and chillers, and specially for the isolation fo cooling towers, air-cooled condensers, etc. Custom isolators with higher deflection and greater load capabilities are also available. EFRSI isolators are available with deflections upto 2" (50 mm) and with load capacities to 5,000 kg. ![]() To assure stability, the springs have a lateral spring stiffness than 1.2 times the rated vertical stiffness and are designed to provide a minimum of 50% overload capacity. Holes are provided in all isolators for bolting to the structure and to the supported equipment. Spring elements are complete with internal noise isolation pads and have an adjusting and leveling bolt as a part of the top load plate assembly. The housings also provide a constant free and operating height to facilitate installation. Rubber to Metal Bonded Anti Vibration MountsĮasyflex Model EFRSI Seismic Control Restrained Spring Vibration Isolators consist of free-standing, large diameter, laterally stable steel springs assembled into welded steel housing assemblies fabricated to limit vertical movement of the isolated equipment if equipment loads are reduced or if the equipment is subjected to large external forces such as a seismic events.Braided SS Hose Connections With Different End Fittings.Twin Sphere Flexible Bellow with Floating Flanges.Solution: Flexible connectors are required to reduce equipment nozzle loads. Problem: Differential motion due to equipment on isolators and piping attached to structure. Solution: Omega Naught Factor (Horizontal forces multiplied by 2.5). Problem: Poor installation of concrete anchors. Solution: All connections must be checked including anchorage of unit to base or isolators, attachment of base to isolators and isolators to structure. Problem: The complete load path from the center of gravity of the unit to the structure is not always considered. Solution: Restrained springs must be used and a certain number of springs may be required to distribute the load properly to the structure. Typically wind forces are higher than seismic, excluding high seismic areas like California. Problem: Horizontal and vertical forces due to wind and/or seismic forces applied at the center-of-gravity of the unit require proper design of the attachment of the unit and/or vibration isolators to the structure. Solution: Certified anchorage calculations must be submitted to verify loading conditions are met for each piece of equipment. Seismic/Wind Requirements Problem: Forces are determined by a number of factors including: project location, site class, risk category, component importance factor and equipment location equipment relative to the overall height of the building. Solution: Restrained isolators with upward limit stops must be used to keep unit from becoming displaced and damaging piping connections. Weight Issues Problem: Unit must be drained for cleaning at required intervals. Problem: Some Cooling Towers are not designed to be point loaded on isolators. ![]() Proper calculations should be performed for quantity and locations of the hangers. Depending on pipe size, this set-up usually requires 3 to 5 hangers on either side. Spring hangers or restrained spring isolators are recommended on the inlet and discharge piping until the vibration is dissipated. A minimum of 2-inch deflection is suggested so that the springs are operating at a high efficiency. Due to the potential change in the operating weight of the cooling tower, restrained isolators are recommended. Unlike airborne noise, structure-borne noise is very difficult to diagnose post design. Vibration from the fans is transferred to the structure and can create noise problems in different areas of the building. Structure-Borne Vibration Problem: This is noise traveling through the structure instead of the air.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |