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VIBRATION CONTROL & SEISMIC RESTRAINT
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SECTION 23 0548
VIBRATION CONTROL AND SEISMIC RESTRAINT
PART 1 - GENERAL .............................................................................................................................. 1
1.1 GENERAL PROVISIONS ........................................................................................................... 1
1.2 DESCRIPTION ........................................................................................................................... 1
1.3 SUBMITTAL DATA REQUIREMENTS ...................................................................................... 3
1.4 CODE AND STANDARDS REQUIREMENTS ........................................................................... 3
1.5 MANUFACTURER'S RESPONSIBILITY ................................................................................... 4
1.6 RELATED WORK ...................................................................................................................... 4
1.7 DESIGN REQUIREMENTS ....................................................................................................... 4
1.8 QUALITY ASSURANCE ............................................................................................................ 4
PART 2 - PRODUCTS ........................................................................................................................... 5
2.1 INTENT ...................................................................................................................................... 5
2.2 PRODUCT DESCRIPTIONS ..................................................................................................... 5
PART 3 - EXECUTION ........................................................................................................................ 13
3.1 GENERAL ................................................................................................................................ 13
3.2 VIBRATION ISOLATION AND SEISMIC RESTRAINT OF PIPING, DUCTWORK, AND
CONDUIT ................................................................................................................................. 14
3.3 SEISMIC RESTRAINT EXCLUSIONS ..................................................................................... 16
3.4 INSTALLATION OF VIBRATION ISOLATION EQUIPMENT .................................................. 17
END OF INDEX
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VIBRATION CONTROL & SEISMIC RESTRAINT
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SECTION 23 0548
VIBRATION CONTROL AND SEISMIC RESTRAINT
PART 1 - GENERAL
1.1 GENERAL PROVISIONS
A. Attention is directed to the CONTRACT AND GENERAL CONDITIONS and all Sections within
DIVISION 01 - GENERAL REQUIREMENTS which are hereby made a part of this Section of
the Specifications.
1.2 DESCRIPTION
A. General: The work noted within Section 230548 is referenced by Divisions 21 0001, 22 0001,
23 0000, 26 0000. Provide all necessary labor & material in each division as required herein.
B. Intent:
1. All mechanical, plumbing, fire protection & electrical equipment, piping, conduits and
ductwork shall be mounted on vibration isolators to prevent the transmission of vibration
and mechanically transmitted sound to the building structure. Vibration isolators shall be
selected in accordance with the weight distribution so as to produce reasonably uniform
deflections.
2. All isolators and isolation materials shall be of the same manufacturer and shall be
certified by the manufacturer.
3. It is the intent of the seismic portion of this specification to keep all mechanical, plumbing,
fire protection and electrical building system components in place during a seismic event.
4. All such systems must be installed in strict accordance with seismic codes, component
manufacturer's, and building construction standards. Whenever a conflict occurs
between the manufacturer's or construction standards, the most stringent shall apply.
5. This specification is considered to be minimum requirements for seismic consideration
and is not intended as a substitute for legislated, more stringent, national, state or local
construction requirements.
6. Any variance or non-compliance with these specification requirements shall be corrected
by the contractor in an approved manner.
C. The work in this section includes, but is not limited to the following:
1. Vibration isolation for piping, conduits, ductwork and equipment.
2. Equipment isolation bases.
3. Flexible piping connections.
4. Seismic restraints for isolated equipment.
5. Seismic restraints for non-isolated equipment.
6. Certification of seismic restraint designs and installation supervision.
7. Certification of seismic attachment of housekeeping pads.
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8. All mechanical, plumbing, fire protection and electrical systems. Equipment buried
underground is excluded but entry of services through the foundation wall is included.
Equipment referred to below is typical. (Equipment not listed is still included in this
specification).
AC Units Heat Exchangers
Air Cooled Condensing Units Light Fixtures
Air Separators Piping
Bus Ducts Pumps (all types)
Cable Trays Rooftop Units
Heat Pump Chillers Switchgear
Cooling Tower/Fluid Coolers
Conduit
Tanks (all types)
Ductwork Transformers
Electrical Panels Unit Heaters
Fans (all types) Variable Frequency Drives
Generators VAV Boxes
D. Definitions:
1. Life Safety Systems
a. All systems involved with fire protection including sprinkler piping, fire pumps,
jockey pumps, fire pump control panels, service water supply piping, water tanks,
fire dampers and smoke exhaust systems.
b. All systems involved with and/or connected to emergency power supply including
all generators, transfer switches, transformers, and all flowpaths to fire protection
and/or emergency lighting systems.
c. All medical and life support systems.
d. Fresh air & relief systems on emergency control sequence including air handlers,
conduit, duct, dampers, etc.
2. Positive Attachment
a. A positive attachment is defined as a cast-in anchor, a drill-in wedge anchor, a
double sided beam clamp loaded perpendicular to a beam, or a welded or bolted
connection to structure. Single sided "C" type beam clamps for support rods of
overhead piping, ductwork, fire protection, electrical conduit, bus duct, or cable
trays, etc. are not acceptable as seismic anchor points.
3. Transverse Bracing
a. Restraint(s) applied to limit motion perpendicular to the centerline of the pipe, duct
or conduit.
4. Longitudinal Bracing
a. Restraint(s) applied to limit motion parallel to the centerline of the pipe, duct or
conduit.
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1.3 SUBMITTAL DATA REQUIREMENTS
A. In addition to requirements of Section 01 3300, the manufacturer of vibration isolation and
seismic restraints shall provide submittals for products as follows:
1. Descriptive Data
a. Catalog cuts or data sheets on vibration isolators and specific restraints detailing
compliance with the specification.
b. Detailed schedules of flexible and rigidly mounted equipment, showing vibration
isolators and seismic restraints by referencing numbered descriptive drawings.
2. Shop Drawings
a. Submit fabrication details for equipment bases including dimensions, structural
member sizes and support point locations.
b. Provide all details of suspension and support for ceiling hung equipment.
c. Where walls, floors, slabs or supplementary steel work are used for seismic
restraint locations, details of acceptable attachment methods for ducts, conduit and
pipe must be included and approved before the condition is accepted for
installation. Restraint manufacturers' submittals must include spacing, static loads
and seismic loads at all attachment and support points.
d. Provide specific details of seismic restraints and anchors; include number, size
and locations for each piece of equipment.
3. Seismic Certification and Analysis
a. Seismic restraint calculations must be provided for all connections of equipment to
the structure. Calculations must be stamped by a registered professional engineer
with at least five years of seismic design experience, licensed in the state of the
job location.
b. All restraining devices shall have a pre-approval number from California OSHPD or
some other recognized government agency showing maximum restraint ratings.
Calculations (including the combining of tensile and shear loadings) to support
seismic restraint designs must be stamped by a registered professional engineer
with at least five years of seismic design experience and licensed in the state of
the job location. Testing and calculations must include both shear and tensile
loads as well as one test or analysis at 450 to the weakest mode.
c. Analysis must indicate calculated dead loads, static seismic loads and capacity of
materials utilized for connections to equipment and structure. Analysis must detail
anchoring methods, bolt diameter, embodiment and/or welded length. All seismic
restraint devices shall be designed to accept, without failure, the forces required
acting through the equipment center of gravity. Overturning moments may exceed
forces at ground level.
1.4 CODE AND STANDARDS REQUIREMENTS
A. Typical Applicable Codes, Standards, and Categories:
1. International Building Code 2015 with an effective peak acceleration coefficient of 0.15.
2. Massachusetts State Building Code, Latest Adopted Edition.
3. Seismic hazard exposure group of I, II, III and seismic performance category of C, D.
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1.5 MANUFACTURER'S RESPONSIBILITY
A. Manufacturer of vibration isolation and seismic control equipment shall have the following
responsibilities:
1. Determine vibration isolation and seismic restraint sizes and locations.
2. Provide vibration isolation and seismic restraints.
3. Provide calculations and materials if required for restraint of unisolated equipment.
4. Provide installation instructions, drawings and trained field supervision to insure proper
installation and performance.
1.6 RELATED WORK
A. Housekeeping Pads:
1. Housekeeping pads shall be coordinated with restraint vendor and sized to provide a
minimum edge distance of ten (10) bolt diameters all around the outermost anchor bolt to
allow development of full drill-in wedge anchor ratings. If cast-in anchors are to be used,
the housekeeping pads shall be sized to accommodate the ACI requirements for bolt
coverage and embodiment.
B. Supplementary Support Steel:
1. Contractor shall supply supplementary support steel for all equipment, piping, ductwork,
etc. including roof mounted equipment.
C. Attachments:
1. Contractor shall supply restraint attachment plates cast into housekeeping pads, concrete
inserts, double sided beam clamps, etc. in accordance with the requirements of the
vibration vendor's calculations.
1.7 DESIGN REQUIREMENTS
A. Design isolators for equipment installed outdoors to provide adequate restraint to withstand the
force of a 140 mph wind applied to any exposed surface of the isolated equipment. Isolators for
outdoor equipment shall have bolt holes for attachment to equipment and to supports. The
vibration isolation Vendor shall submit verifying shear and over turning calculations, for their
product and equipment installation arrangement, stamped by a licensed Professional Engineer.
The design and supply of miscellaneous support steel above and below isolators will not be the
responsibility of the vibration isolation manufacturer.
1.8 QUALITY ASSURANCE
A. Coordinate the size, location, and special requirements of vibration isolation equipment and
systems with other trades. Coordinate plan dimensions with size of housekeeping pads.
B. Provide vibration isolators of the appropriate sizes, with the proper loading to meet the specified
deflection requirements.
C. Supply and install any incidental materials such as mounting brackets, attachments and other
accessories as may be needed to meet the requirements stated herein, even if not expressly
specified or shown on the drawings, without claim for additional payment.
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D. Verify correctness of equipment model numbers and conformance of each component with
manufacturer's specifications.
E. Should any rotating equipment cause excessive noise or vibration when properly installed on
the specified isolators, the Contractor shall be responsible for rebalancing, realignment, or other
remedial work required to reduce noise and vibration levels. Excessive is defined as exceeding
the manufacturer's specifications for the unit in question.
PART 2 - PRODUCTS
2.1 INTENT
A. All vibration isolators and seismic restraints described in this section shall be the product of a
single manufacturer. Mason Industry's products are the basis of these specifications; products
of other manufacturers are acceptable provided their systems strictly comply with the
specification.
B. For the purposes of this project, failure is defined as the discontinuance of any attachment point
between equipment or structure, vertical permanent deformation greater than 1/8 inch and/or
horizontal permanent deformation greater that 1/4 inch.
2.2 PRODUCT DESCRIPTIONS
A. Vibration Isolators and Seismic Restraints.
GENERAL:
1. All metal parts installed out-of-doors shall be corrosion resistant after fabrication.
Galvanizing shall meet ASTM Salt Spray Test Standards and Federal Test Standard No.
14.
2. Isolators installed out-of-doors shall have base plates with bolt holes for fastening the
isolators to the support members.
3. Isolator types are scheduled to establish minimum standards. At the Contractor's option,
labor-saving accessories can be an integral part of isolators supplied to provide initial lift
of equipment to operating height, hold piping at fixed elevations during installation and
initial system filling operations, and similar installation advantages. Accessories and
seismic restraint features must not degrade the isolation performance of the isolators.
4. Static deflection of isolators shall be as provided in the EXECUTION section and as
shown on the drawings. All static deflections stated are the minimum acceptable
deflection for the mounts under actual load. Isolators selected solely on the basis of rated
deflections are not acceptable and will be disapproved.
SPECIFICATION:
1. Two layers of 3/4" thick neoprene pad consisting of 2" square waffle modules separated
horizontally by a 16-gauge galvanized shim. Load distribution plates shall be used as
required. Pads shall be Type Super "W" as manufactured by Mason Industries, Inc.
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2. Bridge-bearing neoprene mountings shall have a minimum static deflection of 0.2" and all
directional seismic capability. The mount shall consist of a ductile iron casting containing
two separated and opposing molded neoprene elements. The elements shall prevent the
central threaded sleeve and attachment bolt from contacting the casting during normal
operation. The shock absorbing neoprene materials shall be compounded to bridge-
bearing specifications. Mountings shall have an Anchorage Pre-approval "R” Number
from OSHPD in the State of California verifying the maximum certified horizontal and
vertical load ratings. Mountings shall be Type BR as manufactured by Mason Industries,
Inc.
3. Sheet metal panels shall be bolted to the walls or supporting structure by assemblies
consisting of a neoprene bushing cushioned between 2 steel sleeves. The outer sleeve
prevents the sheet metal from cutting into the neoprene. Enlarge panel holes as
required. Neoprene elements pass over the bushing to cushion the back panel
horizontally. A steel disc covers the inside neoprene element and the inner steel sleeve
is elongated to act as a stop so tightening the anchor bolts does not interfere with panel
isolation in 3 planes. Bushing assemblies can be applied to the ends of steel cross
members where applicable. All neoprene shall be bridge bearing quality. Bushing
assemblies shall be type PB as manufactured by Mason Industries, Inc.
4. A one (1) piece molded bridge bearing neoprene washer/bushing. The bushing shall
surround the anchor bolt and have a flat washer face to avoid metal to metal contact.
Neoprene bushings shall be type HG as manufactured by Mason Industries, Inc.
5. Spring isolators shall be free standing and laterally stable without any housing and
complete with a molded neoprene cup or 1/4" neoprene acoustical friction pad between
the baseplate and the support. All mountings shall have leveling bolts that must be rigidly
bolted to the equipment. Spring diameters shall be no less than 0.8 of the compressed
height of the spring at rated load. Springs shall have a minimum additional travel to solid
equal to 50% of the rated deflection. Submittals shall include spring diameters,
deflection, compressed spring height and solid spring height. Mountings shall be Type
SLF as manufactured by Mason Industries, Inc.
6. Restrained spring mountings shall have an SLF mounting as described in Specification 5,
within a rigid housing that includes vertical limit stops to prevent spring extension when
weight is removed. The housing shall serve as blocking during erection. A steel spacer
shall be removed after adjustment. Installed and operating heights are equal. A minimum
clearance of 1/2" shall be maintained around restraining bolts and between the housing
and the spring so as not to interfere with the spring action. Limit stops shall be out of
contact during normal operation. Since housings will be bolted or welded in position
there must be an internal isolation pad. Housing shall be designed to resist all seismic
forces. Mountings shall have Anchorage Pre-approval "R" Number from OSHPD in the
state of California certifying the maximum certified horizontal and vertical load ratings.
Mountings shall be SLR as manufactured by Mason Industries, Inc.
7. Spring mountings as in specification 5 built into ductile iron or steel housing to provide all
directional seismic snubbing. The snubber shall be adjustable vertically and allow a
maximum of 1/4 inch travel in all directions before contacting the resilient snubbing collars. Mountings shall have an Anchorage Pre-approval "R" number from OSHPD in
the State of California verifying the maximum certified horizontal and vertical load ratings.
Mountings shall be SSLFH as manufactured by Mason Industries, Inc.
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8. Air Springs shall be manufactured with upper and lower steel sections connected by a
replaceable flexible nylon reinforced neoprene element. Air spring configuration shall be
multiple bellows to achieve a maximum natural frequency of 3 Hz. Air Springs shall be
designed for a burst pressure that is a minimum of three times the published maximum
operating pressure. All air spring systems shall be connected to either the building
control air or a supplementary air supply and equipped with three leveling valves to
maintain leveling within plus or minus 1/8". Submittals shall include natural frequency,
load and damping tests performed by an independent lab or acoustician. Air Springs
shall be Type MT and leveling valves Type LV as manufactured by Mason Industries, Inc.
9. Restrained air spring mountings shall have an MT air spring as described in Specification
8, within a rigid housing that includes vertical limit stops to prevent air spring extension
when weight is removed. The housing shall serve as blocking during erection. A steel
spacer shall be removed after adjustment. Installed and operating heights are equal. A
minimum clearance of 1/2" shall be maintained around restraining bolts and between the
housing and the air spring so as not to interfere with the air spring action. Limit stops
shall be out of contact during normal operation. Housing shall be designed to resist all
seismic forces. Mountings shall be SLR-MT as manufactured by Mason Industries, Inc.
10. Hangers shall consist of rigid steel frames containing minimum 1 1/4" thick neoprene
elements at the top and a steel spring with general characteristics as in specification 5
seated in a steel washer reinforced neoprene cup on the bottom. The neoprene element
and the cup shall have neoprene bushings projecting through the steel box. To maintain
stability, the boxes shall not be articulated as clevis hangers nor the neoprene element
stacked on top of the spring. Spring diameters and hanger box lower hole sizes shall be
large enough to permit the hanger rod to swing through a 30° arc from side to side before
contacting the rod bushing and short circuiting the spring. Submittals shall include a
hanger drawing showing the 30° capability. Hangers shall be type 30° as manufactured
by Mason Industries, Inc.
11. Hangers shall be as described in specifications 10, but they shall be pre-compressed and
locked at the rated deflection by means of a resilient seismic upstop to keep the piping or
equipment at a fixed elevation during installation. The hangers shall be designed with a
release mechanism to free the spring after the installation is complete and the hanger is
subjected to its full load. Deflection shall be clearly indicated by means of a scale.
Submittals shall include a drawing of the hanger showing the 30° capability. Hangers
shall be type PC30N as manufactured by Mason Industries, Inc.
12. Seismic Cable Restraints shall consist of galvanized steel aircraft cables sized to resist
seismic loads with a minimum safety factor of two and arranged to provide all-directional
restraint. Cable end connections shall be steel assemblies that swivel to final installation
angle and utilize two clamping bolts to provide proper cable engagement. Cables must
not be allowed to bend across sharp edges. Cable assemblies shall have an Anchorage
Pre-approval "R" Number from OSHPD in the State of California verifying the maximum
certified load ratings. Cable assemblies shall be Type SCB at the ceiling and at the
clevis bolt, SCBH between the hanger rod nut and the clevis or SCBV if clamped to a
beam all as manufactured by Mason Industries, Inc. 13. Seismic solid braces shall consist of steel angles or channels to resist seismic loads with
a minimum safety factor of 2 and arranged to provide all directional restraint. Seismic
solid brace end connectors shall be steel assemblies that swivel to the final installation
angle and utilize two through bolts to provide proper attachment. Seismic solid brace
assembly shall have anchorage pre-approval "R" number from OSHPD in the state of
California verifying the maximum certified load ratings. Solid seismic brace assemblies shall be type SSB as manufactured by Mason Industries, Inc.
Note: Specifications 12 - 14 apply to trapeze as well as clevis hanger locations. At
trapeze anchor locations piping must be shackled to the trapeze. Specifications apply to
hanging equipment as well.
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14. Steel angles, sized to prevent buckling, shall be clamped to pipe or equipment rods
utilizing a minimum of three ductile iron clamps at each restraint location when required.
Welding of support rods is not acceptable. Rod clamp assemblies shall have an
Anchorage Pre-approval "R" Number from OSHPD in the State of California. Rod clamp
assemblies shall be Type SRC as manufactured by Mason Industries, Inc.
15. Pipe clevis cross bolt braces are required in all restraint locations. They shall be special
purpose performed channels deep enough to be held in place by bolts passing over the
cross bolt. Clevis cross braces shall have an Anchorage Pre-approval "R" Number from
OSHPD in the State of California. Clevis cross brace shall be type CCB as manufactured
by Mason Industries, Inc.
16. All-directional seismic snubbers shall consist of interlocking steel members restrained by
a one-piece molded neoprene bushing of bridge bearing neoprene. Bushing shall be
replaceable and a minimum of 1/4 inch thick. Rated loading shall not exceed 1,000 psi.
A minimum air gap of 1/8 inch shall be incorporated in the snubber design in all directions
before contact is made between the rigid and resilient surfaces. Snubber end caps shall
be removable to allow inspection of internal clearances. Neoprene bushings shall be
rotated to insure no short circuits exist before systems are activated. Snubbers shall
have an Anchorage Pre-approval "R" Number from OSHPD in the State of California
verifying the maximum certified horizontal and vertical load ratings. Snubber shall be
Type Z-1 225 as manufactured by Mason Industries, Inc.
17. All directional seismic snubbers shall consist of interlocking steel members restrained by
shock absorbent rubber materials compounded to bridge bearing specifications.
Elastomeric materials shall be replaceable and a minimum of 3/4" thick. Rated loadings
shall not exceed 1,000 psi. Snubbers shall be manufactured with an air gap between
hard and resilient material of not less than 1/8" nor more that 1/4". Snubbers shall be
installed with factory set clearances. The capacity of the seismic snubber at 3/8"
deflection shall be equal or greater than the load assigned to the mounting grouping
controlled by the snubber multiplied by the applicable "G" force. Submittals shall include
the load deflection curves up to 1/2" deflection in the x, y and z planes. Snubbers shall
have an anchorage pre-approval "R" number from OSHPD in the state of California
verifying the maximum certified horizontal and vertical load ratings. Snubbers shall be
series Z-101 1 as manufactured by Mason Industries, Inc.
18. Stud wedge anchors shall be manufactured from full diameter wire, not from undersized
wire that is "rolled up" to create the thread. The stud anchor shall also have a safety
shoulder which fully supports the wedge ring under load. The stud anchors shall have an
evaluation report number from the I.C.B.0 Evaluation Service, Inc. verifying its allowable
loads. Drill-in stud wedge anchors shall be type SAS as manufactured by Mason
Industries, Inc.
19. Female wedge anchors are preferred in floor locations so isolators or equipment can be
slid into place after the anchors are installed. Anchors shall be manufactured from full
diameter wire, and shall have a safety shoulder to fully support the wedge ring under
load. Female wedge anchors shall have an evaluation report number from the I.C.B.0 Evaluation Service, Inc. verifying to its allowable loads. Drill-in female wedge anchors
shall be type SAB as manufactured by Mason Industries, Inc.
20. Vibration isolation manufacturer shall furnish integral structural steel bases. Rectangular
bases are preferred for all equipment. Centrifugal refrigeration machines and pump
bases may be T or L shaped where space is a problem. Pump bases for split case pump
shall include supports for suction and discharge elbows. All perimeter members shall be steel beams with a minimum depth equal to 1/10 of the longest dimension of the base.
Base depth need not exceed 14' provided that the deflection and misalignment is kept
within acceptable limits as determined by the manufacturer. Height saving brackets shall
be employed in all mounting locations to provide a base clearance of 1 ". Bases shall be
type WF as manufactured by Mason Industries, Inc.
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21. Vibration isolation manufacturer shall furnish rectangular steel concrete pouring forms for
floating and inertia foundations. Bases for split case pumps shall be large enough to
provide for suction and discharge elbows. Bases shall be a minimum of 1/1 2 of the
longest dimension of the base but not less than 6". The base depth need not exceed 1 2"
unless specifically recommended by the base manufacturer for mass or rigidity. Forms
shall include minimum concrete reinforcing consisting of 1/2" bars welded in place on 6"
centers running both ways in a layer 1 1/2" above the bottom. Forms shall be furnished
with steel templates to hold the anchor bolts sleeves and anchors while concrete is being
poured. Height saving brackets shall be employed in all mounting locations to maintain a
1 " clearance below the base. Wooden formed bases leaving a concrete rather than a
steel finish are not acceptable. Base shall be type BMK or K as manufactured by Mason
Industries, Inc.
22. Roof Curb (by HVAC Contractor)
a. Curb mounted rooftop equipment shall be mounted on structural spring isolation
curbs that bear directly on the roof support structure, and are flashed and
waterproofed into the roof's membrane waterproofing system. All spring locations
shall have removable waterproof covers to allow for spring adjustment and/or
removal. Springs shall be Type A.
b. Unit shall be provided with wood nailer and flashing.
c. Curbs shall meet all NRCA Standards.
d. Curbs shall be similar to Novia Associates VibCurb III or equal having a minimum
3" rated static deflection and be 24” high.
e. Vibration control: The spring roof curb shall have the top isolated or floating rail
attached in a manner to the fixed lower portion of the curb without short circuiting
or bridging between the two. Restraining bolt(s) or threaded rod shall be of
sufficient size to withstand the applied wind & or seismic forces at each spring
pack location.
f. An alignment bolt shall be installed before connecting the floating to non-floating
parts to guarantee perfect centering of the restraining bolts.
g. Weather proofing & air seal: The spring curb must keep the weather (air and
water) out and any airflow from the RTU in. The weather seal must not have the
ability to fail and allow water or air into the building.
h. The use of exposed exterior neoprene or some other elastomer material to seal
the top floating rail from the base of the curb in not acceptable.
i. Vibration Mountings: Provide a rubber gasket covered by formed galvanized sheet
metal top flashing that overhangs the top wood nailer and galvanized bottom
flashing. The overlapping shall effectively cover the rubber gasket so it is protected
from the elements.
j. The top flashing / support rail shall be 14 ga. G60–Zc steel formed with 90 bends
that extend down to the wood nailer. Provide a counter flashing member with a
sponge gasket attached that presses up against the horizontal bend. The seal
shall be replaceable, protected from the elements and easy to install. k. Curb side material: Provide 12 Ga. G60 galvanized steel for curb side construction.
All side and end seam between sheets shall be continuously welded, corner joints
to be caulked and bolted.
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l. Structural Capability:
1) Curbs shall be installed on metal decking/concrete slab. Air handling unit
load shall be properly distributed. Coordinate curb construction with pitch of
roof. Curbs shall be built to match the roof pitch in accordance with all
requirements of this project. Positive attachment of the curb to the structure
is imperative. Pitch correction shall be fabricated from 12-gauge galvanized
material and be continuous on all sides and ends. Field fabricated and
installed tube steel stub-ups are not acceptable. HVAC contractor shall
provide detailed information to the curb manufacturer regarding pitch
correction.
2) Plenum Sections: The side material must be capable of handling the static
pressure developed by the fans and not ‘oil can’. Provide spanning bar
joists as required to support plenum installation (even when the spring
pockets are center span).
3) Provide a continuous bottom tube steel member or side material of sufficient
strength. Mechanical contractor shall coordinate and verify all dimensions,
weights, roof penetrations, etc. with the Structural Engineer prior to
installation.
4) Curb Insulation: Provide spring curbs with a space between the floating and
non-floating parts for the installation of insulation. Curb manufacturer shall
provide factory installed insulation adhered to roof curb. Curbs shall be
externally factory insulated with a 1.7” thick R-12 foam insulation, FM Class
1 and UL Class A Ratings, with bonded fiber reinforced facer.
m. Protection: Curbs shall be completely shrink-wrapped during shipping.
n. Mechanical contractor shall provide all necessary materials to completely weather
proof and sound proof the curb installation.
o. Additional features:
1) Sound barrier: Provide a sound barrier package, consisting of G60
galvanized back-to-back angles. Sound barrier package shall be capable of
supporting two layers of 1/2" concrete board with a maximum deflection over
the width of the curb of L/360. Cement board furnished and installed by the
HVAC Contractor. Overlap all joints, caulk all seams and edges.
Transmission Loss & STC shall be as shown as follows. Sound
Transmission Loss at Frequency (Cycles per second) of (125)=20,
(250)=27, (500)=30, (1000)=32, (2000)=30, (4000)=38, (STC)=31.
2) Provide with framed Supply & Return air duct openings. Openings shall
match duct sizes and have 1" galvanized steel flanges.
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3) Plenum sections: Where indicated on the drawings, provide in the interior of
the curb, double wall acoustical floor, walls and plenum divider. All
insulation shall be 2" thick fiber glass acoustical duct liner with reinforced
coating system. Insulation acoustical performance shall be as follows. Liner
shall not support microbial growth and shall be EPA registered and pass
ASTM C 1071 & ASTM G21 bacterial tests conducted in accordance with
ASTM G22. Floors up to 90" curb I.D. width shall be constructed of 22 Ga.,
20 Ga. thereafter, solid G60 galvanized bottom panels and 22 Ga.
galvanized perforated 22.7% open area top panel. Floor shall be attached to
walls and plenum divider to provide an airtight plenum. Walls shall have 22
Ga. galvanized perforated 22.7% open area inside panels. Plenum divider
shall be double wall 22 Ga. perforated galvanized 22.7% open area panel
on the supply side with a 14 gauge solid panel opposite. Sound Absorption
Coefficient at Frequency (Cycles per second) of (125)=.23, (250)=.64,
(500)=.99, (1000)=1.05, (2000)=1.00, (4000)=.98, (NRC)=.90.
23. Flexible spherical expansion joints shall employ peroxide cured EPDM in the covers,
liners and Dacron tire cord friction ring. Solid steel rings shall be used within the raised
face rubber ends to prevent pullout. Flexible cable bead wire is not acceptable. Sizes 2"
and larger shall have two spheres reinforced with a ring between spheres to maintain
shape and complete with split ductile iron or steel flanges with hooked or similar
interlocks. Sizes 16' to 24" may be single sphere. Sizes 3/4" to 1 1/2" may have
threaded bolted flange assemblies, one sphere and cable retention. 14" and smaller
connectors shall be rated at 250 psi up to 190°F. with a uniform drop in allowable
pressure to 190 psi at 250°F. 16" and larger connectors are rated 180 psi at 190°F. and
135 psi at 250°F. Safety factors to burst and flange pullout shall be a minimum of 3/1.
All joints must have permanent markings verifying a 5-minute factory test at twice the
rated pressure. Concentric reducers to the above specifications may be substituted for
equal ended expansion joints.
Expansion joints shall be installed in piping gaps equal to the length of the expansion
joints under pressure. Control rods need only be used in unanchored piping locations
where the manufacturer determines the installation exceeds the pressure requirement
without control rods, as control rods are not desirable in seismic work. If control rods are
used, they must have 1/2" thick Neoprene washer bushings large enough in area to take
the thrust at 1000 psi maximum on the washer area. Expansion joints shall be installed
on the equipment side of the shut off valves.
Submittals shall include two test reports by independent consultants showing minimum
reductions of 20 DB in vibration accelerations and 10 DB in sound pressure levels at
typical blade passage frequencies on this or a similar product by the same manufacturer.
All expansion joints shall be installed on the equipment side of the shut off valves.
Expansion joints shall be SAFEFLEX SFDEJ, SFEJ, SFDCR or SFU and Control Rods
CR as manufactured by Mason Industries, Inc.
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24. Flexible stainless steel hose shall have stainless steel braid and carbon steel fittings.
Sizes 3" and larger shall be flanged. Smaller sizes shall have male nipples. Minimum
lengths shall be as tabulated:
Flanged Male Nipples
3 x 14 10 x 26 1/2 x 9 1-1/2 x 13
4 x 15 12 x 28 3/4 x 10 2 x 14
5 x 19 14 x 30 1 x 11 2-1/2 x 18
6 x 20 16 x 32 1-1/4 x 12
8 x 22
Hoses shall be installed on the equipment side of the shut-off valves horizontally and
parallel to the equipment shafts wherever possible. Hoses shall be type BSS as
manufactured by Mason Industries, Inc.
25. All-directional acoustical pipe anchor, consisting of two sizes of steel tubing separated by
a minimum 1/2" thick 60 durometer neoprene. Vertical restraint shall be provided by
similar material arranged to prevent vertical travel in either direction. Allowable loads on
the isolation material should not exceed 500 psi and the design shall be balanced for
equal resistance in any direction. All-directional anchors shall be type ADA as
manufactured by Mason Industries, Inc.
26. Pipe guides shall consist of a telescopic arrangement of two sizes of steel tubing
separated by a minimum 1/2" thickness of 60 durometer neoprene. The height of the
guides shall be preset with a shear pin to allow vertical motion due to pipe expansion or
contraction. Shear pin shall be removable and reinsertable to allow for selection of pipe
movement. Guides shall be capable of + 1 5/8" motion, or to meet location requirements.
Pipe guides shall be type VSG as manufactured by Mason Industries, Inc.
27. Split Wall Seals consist of two bolted pipe halves with minimum 3/4" thick neoprene
sponge bonded to the inner faces. The seal shall be tightened around the pipe to
eliminate clearance between the inner sponge face and the piping. Concrete may be
packed around the seal to make it integral with the floor, wall or ceiling if the seal is not
already in place around the pipe prior to the construction of the building member. Seals
shall project a minimum of I" past either face of the wall. Where temperatures exceed
240°F., 10# density fiberglass may be used in lieu of the sponge. Seals shall be Type
SWS as manufactured by Mason Industries, Inc.
28. The horizontal thrust restraint shall consist of a spring element in series with a neoprene
molded cup as described in specification 5 with the same deflection as specified for the
mountings or hangers. The spring element shall be designed so it can be preset for
thrust at the factory and adjusted in the field to allow for a maximum of 1/4" movement at
start and stop. The assembly shall be furnished with 1 rod and angle brackets for
attachment to both the equipment and the duct work or the equipment and the structure.
Horizontal restraints shall be attached at the centerline of thrust and symmetrical on
either side of the unit. Horizontal thrust restraints shall be type WBI/WBD as
manufactured by Mason Industries, Inc.
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PART 3 - EXECUTION
3.1 GENERAL
A. All vibration isolators and seismic restraint systems must be installed in strict accordance with
the manufacturers written instructions and all certified submittal data. At the completion of all
construction work the vibration and seismic device supplier shall inspect all installations and
provided a written report of installation compliance to the engineer of record. A copy of this
written certification shall also be provided in the operations manual provided to the owner.
B. Installation of vibration isolators and seismic restraints must not cause any change of position of
equipment, piping or duct work resulting in stresses or misalignment.
C. No rigid connections between equipment and the building structure shall be made that degrades
the noise and vibration control system herein specified.
D. The contractor shall not install any equipment, piping, duct or conduit which makes rigid
connections with the building unless isolation is not specified. "Building" includes, but is not
limited to, slabs, beams, columns, studs and walls.
E. Coordinate work with other trades to avoid rigid contact with the building.
F. Any conflicts with other trades which will result in rigid contact with equipment or piping due to
inadequate space or other unforeseen conditions should be brought to the architects/engineer’s
attention prior to installation. Corrective work necessitated by conflicts after installation shall be
at the responsible contractor’s expense.
G. Bring to the architects/engineer’s attention any discrepancies between the specifications and
the field conditions or changes required due to specific equipment selection, prior to installation.
Corrective work necessitated by discrepancies after installation shall be at the responsible
contractor’s expense.
H. Correct, at no additional cost, all installations which are deemed defective in workmanship and
materials at the contractor’s expense.
I. Overstressing of the building structure must not occur because of overhead support of
equipment. Contractor must submit loads to the structural engineer of record for approval.
Generally bracing may occur from:
1. Flanges of structural beams.
2. Upper truss cords in bar joist construction.
3. Cast in place inserts or wedge type drill-in concrete anchors.
J. Specification 12 cable restraints shall be installed slightly slack to avoid short circuiting the
isolated suspended equipment, piping or conduit.
K. Specification 12 cable assemblies are installed taut on non-isolated systems. Specification 13
seismic solid braces may be used in place of cables on rigidly attached systems only.
L. At locations where specification 12 or 13 restraints are located, the support rods must be braced
when necessary to accept compressive loads with specification 14 braces.
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M. At all locations where specification 12 or 13 restraints are attached to pipe clevis's, the clevis
cross bolt must be reinforced with specification type 15 braces.
N. Drill-in concrete anchors for ceiling and wall installation shall be specification type 18, and
specification type 19 female wedge type for floor mounted equipment.
O. Vibration isolation manufacturer shall furnish integral structural steel bases as required.
Independent steel rails are not permitted on this project.
P. Hand built elastomeric expansion joints may be used when pipe sizes exceed 24" or specified
movements exceed specification 23 capabilities.
Q. Where piping passes through walls, floors or ceilings the vibration isolation manufacturer shall
provide specification 27 wall seals.
R. Air handling equipment and centrifugal fans shall be protected against excessive displacement
which results from high air thrust in relation to the equipment weight. Horizontal thrust restraint
shall be specification type 28.
S. Locate isolation hangers as near to the overhead support structure as possible.
3.2 VIBRATION ISOLATION AND SEISMIC RESTRAINT OF PIPING, DUCTWORK, AND
CONDUIT
A. Where piping connects to rotating or vibrating mechanical equipment install specification 23
expansion joints or specification 24 stainless hoses if 23 is not suitable for the service.
B. Seismic Restraint of Piping:
1. Seismically restrain all piping listed as a, b or c below. Use specification 12 cables.
a. Fuel oil piping, gas piping, medical gas piping, and compressed air piping.
b. Piping located in boiler rooms, mechanical equipment rooms, and refrigeration
equipment rooms that is 1 1/4" I.D. and larger.
c. All other piping 2 1/2" diameter and larger.
2. Transverse piping restraints shall be at 40' maximum spacing for all pipe sizes, except
where lesser spacing is required to limit anchorage loads.
3. Longitudinal restraints shall be at 80' maximum spacing for all pipe sizes, except where
lesser spacing is required to limit anchorage loads.
4. Where thermal expansion is a consideration, guides and anchors may be used as
transverse and longitudinal restraints provided they have a capacity equal to or greater
than the restraint loads in addition to the loads induced by expansion or contraction.
5. For fuel oil and all gas piping transverse restraints must be at 20' maximum and
longitudinal restraints at 40' maximum spacing.
6. Transverse restraint for one pipe section may also act as a longitudinal restraint for a
pipe section of the same size connected perpendicular to it if the restraint is installed
within 24" of the elbow or TEE or combined stresses are within allowable limits at longer
distances.
7. Hold down clamps must be used to attach pipe to all trapeze members before applying
restraints in a manner similar to clevis supports.
8. Branch lines may not be used to restrain main lines.
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C. Pipe Isolation
1. All chilled water, condenser water, hot water, steam, refrigerant, drain and engine
exhaust piping that is connected to vibration-isolated equipment shall be isolated from the
building structure within the following limits:
Within mechanical rooms;
Within 50' total pipe length of connected vibration-isolated equipment (chillers, pumps, air
handling units, pressure reducing stations, etc.);
At every support point for piping that is greater than 4 inches in diameter.
2. Piping shall be isolated from the building structure by means of vibration isolators,
resilient lateral supports, and resilient penetration sleeve/seals.
3. Isolators for the first three support points adjacent to connected equipment shall achieve
one half the specified static deflection of the isolators supporting the connected
equipment. When the required static deflection of these isolators is greater than 1/2",
Type FSN or HSN isolators shall be used. When the required static deflection is less than
or equal to 1/2", Type FN or HN isolators shall be used. All other pipe support isolators
within the specified limits shall be either Type FN or HN achieving at least 1/4" static
deflection.
4. Where lateral support of pipes is required within the specified limits, this shall be
accomplished by use of resilient lateral supports.
5. Pipes within the specified limits that penetrate the building construction shall be isolated
from the building structure by use of resilient penetration sleeve/seals.
6. Provide flexible pipe connections as called for under Major Equipment above and
wherever shown on the drawings.
D. Seismic restraint of ductwork:
1. Seismically restrain all duct work with specification 12 or 13 restraints as listed below:
a. Restrain rectangular ducts with cross sectional area of 6 sq. ft. or larger.
b. Restrain round ducts with diameters of 28" or larger.
c. Restrain flat oval ducts the same as rectangular ducts of the same nominal size.
1) Transverse restraints shall occur at 30' intervals or at both ends of the duct
run if less than the specified interval. Transverse restraints shall be installed
at each duct turn and at each end of a duct run.
2) Longitudinal restraints shall occur at 60' intervals with at least one restraint
per duct run. Transverse restraints for one duct section may also act as a
longitudinal restraint for a duct section connected perpendicular to it if the
restraints are installed within 4' of the intersection of the ducts and if the
restraints are sized for the larger duct. Duct joints shall conform to
SMACNA duct construction standards.
3) The ductwork must be reinforced at the restraint locations. Reinforcement
shall consist of an additional angle on top of the ductwork that is attached to
the support hanger rods. Ductwork is to be attached to both upper angle
and lower trapeze.
4) A group of ducts may be combined in a larger frame so that the combined
weights and dimensions of the ducts are less than or equal to the maximum
weight and dimensions of the duct for which bracing details are selected.
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5) Walls, including gypsum board nonbearing partitions, which have ducts
running through them may replace a typical transverse brace. Provide
channel framing around ducts and solid blocking between the duct and
frame.
E. Duct Isolation:
1. All sheet metal ducts and air plenums that are within mechanical rooms or within a
distance of 50' total duct length of connected vibration-isolated equipment (whichever is
longer) shall be isolated from the building structure by Type FN, PCF or HN isolators. All
isolators shall achieve 0.1" minimum static deflection.
2. Ducts within the specified limits that penetrate the building construction shall be isolated
from the building structure by use of resilient penetration sleeve/seals.
3. Flexible duct connections shall be provided as called for above under Major Equipment
and wherever shown on the drawings.
F. Seismic Restraint of Electrical Services:
1. All electrical conduit 2-1/2" in diameter and larger shall be restrained with specification
type 12 seismic cable restraints or specification type 13 for seismic solid brace restraints.
2. All electrical bus ducts, cable trays and ladder trays shall be restrained with specification
type 12, seismic cable restraints or specification 13 seismic solid brace restraints.
3. Transverse restraints shall occur at 30' intervals or both ends if the electrical run is less
than the specified interval. Transverse restraints shall be installed at each electrical
services turn and at each end of the electric run.
4. Longitudinal restraints shall occur at 60' intervals with at least one restraint per electric
run. Transverse restraints for one electric section may also act as a longitudinal restraint
for a duct for an electric section connected perpendicular to it if the restraints are installed
within 4' of the intersection of the electric run and if the restraints are sized for the larger
electric run.
5. All rigid floor mounted equipment must have a resilient media between the equipment
mounting hole and the anchor bolt. Neoprene bushings shall be specification type 4 and
anchor bolts shall be specification type 18 or 19.
6. Wall mounted panels shall be mounted with specification type 3 bushings. Floor
mounted panels shall be mounted on specification type 4 bushings. Anchor bolts shall be
specification type 18 or 19.
G. All fire protection piping shall be braced in accordance with NFPA 13 and 14.
H. All mechanical equipment shall be vibration isolated and seismically restrained.
1. All fire protection equipment is considered life safety equipment and shall be seismically
restrained.
3.3 SEISMIC RESTRAINT EXCLUSIONS
A. Piping:
1. All piping less than 2 1/2” except for gas and fire protection piping.
2. All piping in boiler and mechanical equipment rooms less than 1 1/4" I.D.
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3. All clevis or trapeze supported piping suspended from hanger rods where the point of
attachment is less than the 12" in length from the structure to the structural connection of
the clevis or trapeze.
a. All PVC and fiberglass suspended waste or vent pipe 6" in diameter and smaller.
B. Ductwork:
1. Rectangular, square or oval ducts less than 6 sq.ft. in cross sectional area.
2. Round duct less than 28" in diameter.
3. Duct supported by hanger rods where the point of attachment is less than 12" in length
from the structure to the structural connection of the duct work.
C. Electrical:
1. All conduit less than 2 1/2" diameter suspended by individual hanger rods.
2. All clevis or trapeze supported conduits suspended by hanger rods where the point of
attachment is less than 1 2" in length from the structure to the structural connection of the
clevis or trapeze.
3.4 INSTALLATION OF VIBRATION ISOLATION EQUIPMENT
A. General
1. Locations of all vibration isolation devices shall be selected for ease of inspection and
adjustment as well as for proper operation.
2. Installation of vibration isolation equipment shall be in accordance with the
manufacturer's instructions.
B. Isolators
1. All vibration isolators shall be aligned squarely above or below mounting points of the
supported equipment.
2. Isolators for equipment with bases shall be located on the sides of the bases which are
parallel to the equipment shaft unless this is not possible because of physical constraints.
3. Locate isolators to provide stable support for equipment, without excess rocking.
4. Consideration shall be given to the location of the center of gravity of the system and the
location and spacing of the isolators. If necessary, a base with suitable footprint shall be
provided to maintain stability of supported equipment, whether or not such a base is
specifically called for herein.
5. If a housekeeping pad is provided, the isolators shall bear on the housekeeping pad and
the isolator base plates shall rest entirely on the pad.
6. Hanger rods for vibration-isolated support shall be connected to major structural
7. members, not the floor slab between major structural members. Provide suitable
intermediate support members as necessary.
8. Vibration isolation hanger elements shall be positioned as high as possible in the hanger
rod assembly, but not in contact with the building structure, and so that the anger housing
may rotate a full 360° about the rod axis without contacting any object.
9. Parallel running pipes may be hung together on a trapeze that is isolated from the
building. Isolator deflections must be the greatest required by the provisions for pipe
isolation for any single pipe on the trapeze. Do not mix isolated and unisolated pipes on
the same trapeze.
a. Pipes, ducts and equipment shall not be supported from other pipes, ducts and
equipment.
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b. Resiliently isolated pipes, ducts and equipment shall not come in rigid contact with
the building construction or rigidly supported equipment.
c. The installed and operating heights of equipment supported by Type FSNTL
isolators or with Type RC-2 isolation bases shall be identical. Limit stops shall be
out of contact during normal operation. Adjust isolators to provide 1/4" clearance
between the limit stop brackets and the isolator top plate, and between the travel
limit nuts and travel limit brackets.
d. Adjust all leveling bolts and hanger rod bolts so that the isolated equipment is level
and in proper alignment with connecting ducts or pipes.
C. Bases
1. No equipment unit shall bear directly on vibration isolators unless its own frame is
suitably rigid to span between isolators and such direct support is approved by the
equipment manufacturer. This provision shall apply whether or not a base frame is called
for on the schedule. In the case that a base frame is required for the unit because of the
equipment manufacturer's requirements and is not specifically called for on the
equipment schedule, a base frame recommended by the equipment manufacturer shall
be provided at no additional expense.
2. Unless otherwise indicated, there is to be a minimum operating clearance of 1" between
steel rails, steel frame bases or inertia bases and the floor beneath the equipment. The
isolator mounting brackets shall be positioned and the isolators adjusted so that the
required clearance is maintained. The clearance space shall be checked by the
Contractor to ensure that no construction debris has been left to short circuit or restrict
the proper operation of the vibration isolation system.
3. Isolation bases shall be installed in strict accordance with the manufacturer’s instructions.
D. Flexible Duct Connections:
1. Prior to installation of the flexible connection, sheet metal ducts and plenum openings
shall be squarely aligned with the fan discharge, fan intake, or adjacent duct section, and
the gap between connected parts shall be uniform. Flexible duct connections shall not be
installed until this provision is met. There shall be no metal-to-metal contact between
connected sections, and the fabric shall not be stretched taut.
E. Flexible Pipe Connections:
1. Install flexible pipe connections in strict accordance with the manufacturer's instructions.
F. Thrust Restraints:
1. Thrust restraints shall be attached on each side of the fan parallel to the thrust force.
This may require custom brackets or standoffs. The body of the thrust restraint shall not
come in contact with the connected elements. Thrust restraints shall be adjusted to
constrain equipment movement to the specified limit.
G. Grommets:
1. Where grommets are required at hold down bolts of isolators, bolt holes shall be properly
sized to allow for grommets. The hold down bolt assembly shall include washers to
distribute load evenly over the grommets. Bolts and washers shall be galvanized.
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H. Resilient Penetration Sleeve/Seals:
1. Maintain an airtight seal around the penetrating element and prevent rigid contact
between the penetrating element and the building structure. Fit the sleeve tightly to the
building construction and seal airtight on both sides of the construction penetrated with
acoustical sealant.
END OF SECTION
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