Restrained spring isolators11/24/2023 ![]() Solution: Increased Edge distance and/or thicker housekeeping pads may be required. ![]() Problem: Addition of inertia base weight must be factored into structural design for dead and seismic forces. Solution: Proper location of equipment relative to column supports can control beam deflection and therefore reduce vibration in structure. Problem: Increased floor spans tend to increase deflections. They also provide discontinuity in metal piping to reduce motor caused vibrations. They Reduce energy at blade passage frequency traveling through water column. Proper selection is required based on pump size and surrounding space considerations.įlexible connectors are required to isolate the connecting piping from the vibration source. ![]() Spring isolators are required to prevent vibration transfer. Solution: Isolate Equipment Inertia base with spring type isolators – The addition of mass to the bottom of the pump helps lower the center of gravity which reduces vibration. Solution: Flexible connectors are required to reduce equipment nozzle loads. Problem: Differential motion up to 2” in a 20’ story height. Solution: IBC 2015 requires ICC-ES approved anchors for cracked concrete and Omega Naught Factor (Horizontal forces multiplied by 2.5). Problem: Poor installation of concrete anchors. Solution: The load path must be accounted for from the center of gravity of the unit to the structure. Problem: Reinforcement and doweling in of the housekeeping pad to the structure is often overlooked. For concrete attachments, this requires ICC-ES certified anchors. Solution: All connections of the restrained spring isolators must be designed for these loads. The resulting overturning moment creates tension and shear forces that can be very large. Problem: Horizontal and vertical seismic forces are applied at the center of gravity of the unit. Solution: Certified anchorage calculations must be submitted to verify loading conditions are met for each piece of equipment. Seismic 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: Proper selection of isolators is required with safety factor to avoid bottoming out springs or not providing adequate deflection. Uneven Weight Distribution Problem: Water and pipe weights increase force on springs under pump side of unit. Proper calculations should be performed for quantity and locations of the hangers.įlexible connectors are required to isolate the connecting piping from the vibration source. Depending on pipe size, this set-up usually requires 3 to 5 hangers on either side. Solution: Isolate Connecting Piping Spring hangers are recommended on the inlet and discharge piping before the drop and until the vibration is dissipated. Proper selection is required based on pump size and surrounding space considerations. Solution: Isolate Equipment Inertia base with spring type isolators – The addition of mass to the bottom of the pump helps lower the center of gravity which reduces vibration. Vibration can travel through the structure as well as through the connecting piping. If this vibration is transferred to the structure, it can create serious noise problems in many different areas. Non-adjustable inserts are recommended for all air conditioning applications under compressors, air handling units, centrifugal fans and most other constant frequency vibration problems.Structure-Borne Vibration Problem: Pumps are a major source of vibration. Semi-circular Neoprene sponge inserts limit movement during start and stop and prevent contact between the projections of the upper and lower semi-steel castings. These inserts are designed for a minimum of damping in all directions to allow the springs to function properly and develop installed efficiencies that are very close to the theoretical. Since the static deflection of the spring element is much greater than that provided by most rubber materials, these units will perform where it is necessary to establish low natural frequencies or to use a mounting that is more yielding than the supporting floor. Type “C” mountings are specifically designed for noise and vibration free application in critical areas on light concrete or wooden floors. TYPE “C” Spring Mountings provide a packaged solution to troublesome vibration problems.
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Icf blocks basemtn11/24/2023 ![]() The first expanded polystyrene ICF Wall forms were developed in the late 1960s with the expiration of the original patent and the advent of modern foam plastics by BASF. ICF construction has become commonplace for both low rise commercial and high performance residential construction as more stringent energy efficiency and natural disaster resistant building codes are adopted. The units lock together somewhat like Lego bricks and create a form for the structural walls or floors of a building. The forms are interlocking modular units that are dry-stacked (without mortar) and filled with concrete. Insulating concrete form or insulated concrete form (ICF) is a system of formwork for reinforced concrete usually made with a rigid thermal insulation that stays in place as a permanent interior and exterior substrate for walls, floors, and roofs. The cavity is filled with concrete to create the permanent wall. Furthermore, when the air temperature drops below its dew point through contact with a colder surface (like a wall system) water will condense and accumulate on the surface.This insulated concrete form is cut away to show the inner structure of the formwork and the reinforcing bar (rebar). Below the dew point, the vapor turns to liquid water. The dew point is the temperature when the air becomes saturated with water vapor. Condensation occurs when the temperature drops to the dew point. For example, on a humid and hot summer day, when it is cool and dry inside a building, the temperature within the ICF wall system remains uniform and above the dew point, which prevents condensation.Ĭondensation is when water vapor (moisture in the air) changes into liquid water. The insulation stabilizes the temperature and prevents condensation within the concrete walls. ICF’s have insulation on the exterior and interior of the walls separated by a thermal mass of concrete. ICF walls act as vapor retardants therefore, ICF walls do not need vapor barriers. Ultimately, Fox Blocks create an airtight building envelope that limits thermal convection and moisture intrusion through the above-grade walls. Thermal convection is the process where heat moves by the flow of liquid or air molecules from the warm to the cooler side of a wall.įor example, above-grade Fox Blocks create a solid continuous monolithic above-grade concrete wall that provides continuous insulation with an R-value of 23. ![]() Water-Resistant Above-Grade Fox Block ICF WallsĪbove-grade ICF Walls are Air- and Moisture-ResistantĪbove-grade Fox Block ICF walls resist thermal convection and therefore do not need an air and moisture barrier. A quality ICF waterproofing system can eliminate Below-grade water issues. The waterproofing system ensures that moisture in the soil adjacent to the wall will filter through the fabric, then down the dimple board and the drain board, and finally into the drain tile. Proper installation of a waterproofing system over below-grade ICF walls will create a waterproof wall. ![]()
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