Since many vertical inline pumps are not installed on a concrete inertia base, restraining them for extreme events can be a challenge. Utilizing Vibro-Acoustics' pre-engineered pump stands eases installation and ensures code requirements are met. These pump stands are also used with spring hangers and cable restraints for suspended vertical inline pumps.

Seismic Inline Pumps provides rigid support and restraint for vertical inline pumps. These stands can withstand at least 1 g of lateral seismic force for most pump and motor combinations. Neoprene grommet washers are included to minimize shock loading on the anchor bolts from seismic loads helping to ensure the equipment stays in place during and after an extreme.

Neo+ provide vibration isolation for vertical inline pumps (and other equipment). Available in softer and harder durometer versions, these isolators are most effective when used on stiff supporting structures with mid- to high-frequency vibration sources.

For critical applications, Free Spring Isolators or Seismic Free Spring Isolators are recommended.

Vibro-Acoustics' flex connectors are applied to piping connections with vertical inline pumps to isolate the connecting piping and reduce structure-borne noise.

Slab on Grade Design Considerations

Structure-Borne Vibration

Problem: Pumps are a major source of vibration. If this vibration is transferred to the structure, it can create serious noise problems in many different areas. Vibration can travel through the structure as well as through the connecting piping.

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. Spring isolators are required to prevent vibration transfer. Proper selection is required based on pump size and surrounding space considerations. Spring isolators alone can be used for smaller pumps with vibration isolators mounted directly under Vibro-Acoutics Seismic Inline Pump Stands (SIPS).

Solution: Isolate Connecting Piping. Spring hangers are recommended on the inlet and discharge piping before the drop and until the vibration is dissipated. Depending on pipe size, this set-up usually requires 3 to 5 hangers on either side. Proper calculations should be performed for quantity and locations of the hangers.

Problem: Vibration travels from motor through metal pipes.

Solution: Flexible connectors are required to isolate the connecting piping from the vibration source.

Seismic Requirements

Problem: Horizontal and vertical 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: Restrained springs must be used.

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: Certified anchorage calculations must be submitted to verify loading conditions are met for each piece of equipment.

Problem: The complete load path must be followed.

Solution: Often overlooked is the proper reinforcement and doweling in of the housekeeping pad to the structural slab.

Problem: Poor installation of concrete anchors.

Solution: IBC 2015 requires ICC-ES approved anchors for cracked concrete and Omega Naught Factor (Horizontal forces multiplied by 2.5).

Problem: Differential motion up to 2” in a 20’ story height.

Solution: Flexible connectors are required to reduce equipment nozzle loads.

Since many vertical inline pumps are not installed on a concrete inertia base, restraining them for extreme events can be a challenge. Utilizing Vibro-Acoustics' pre-engineered pump stands eases installation and ensures code requirements are met. These pump stands are also used with spring hangers and cable restraints for suspended vertical inline pumps.

Seismic Inline Pumps provides rigid support and restraint for vertical inline pumps. These stands can withstand at least 1 g of lateral seismic force for most pump and motor combinations. Neoprene grommet washers are included to minimize shock loading on the anchor bolts from seismic loads helping to ensure the equipment stays in place during and after an extreme.

The Vibro-Acoustics Seismic Free Spring series provide vibration isolation for vertical inline pumps. The isolator has a seismic restraint housing for greater lateral and vertical support.

Vibro-Acoustics Free Spring series provide vibration isolation for vertical inline pumps that installed on floor or base. These open spring isolators compress on neoprene cups and absorb low and high frequency vibrations.

Vibro-Acoustics' flex connectors are applied to piping connections with vertical inline pumps to isolate the connecting piping and reduce structure-borne noise.

Upper Floor Design Considerations

Structure-Borne Vibration

Problem: Pumps are a major source of vibration. If this vibration is transferred to the structure, it can create serious noise problems in many different areas. Vibration can travel through the structure as well as through the connecting piping.

Solution: 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, Spring isolators are required to prevent vibration transfer. Proper selection is required based on pump size and surrounding space considerations.

Problem: Added weight may be difficult for existing structure.

Solution: Spring isolators alone can be used for smaller pumps with vibration isolators mounted directly under.

Problem: Increased floor spans tend to increase deflection if floor.

Solution: Proper location of equipment relative to column supports can control beam deflection and therefore reduce vibration in structure.

Seismic Requirements

Problem: Horizontal and vertical 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: Restrained springs must be used.

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: Certified anchorage calculations must be submitted to verify loading conditions are met for each piece of equipment.

Problem: Poor installation of concrete anchors.

Solution: IBC 2015 requires ICC-ES approved anchors for cracked concrete and Omega Naught Factor (Horizontal forces multiplied by 2.5).

Problem: Differential motion up to 2” in a 20’ story height.

Solution: Flexible connectors are required to reduce equipment nozzle loads.

Weight Concerns

Problem: Water and pipe weights increase force on springs.

Solution: Proper selection of isolators is required with safety factor to avoid bottoming out springs or not providing adequate deflection.

Problem: Addition of inertia base weight must be factored into structural design for dead and seismic forces.

Solution: Increased Edge distance and/or thicker housekeeping pads may be required. Larger structural beams may be needed.


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