substitution request - Alliance Construction Solutions

Project No.: 10145
550 15 th Street Dual Brand Hotel
03/16/2012
a. Specification “M”: Where piping passes through equipment room walls,
floors or ceilings, the vibration isolator manufacturer shall provide a split
seal consisting of two bolted pipe halves with ¾” or thicker 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 1” past either face of the wall. Where temperatures exceed
240°F, 10 lb./cu.ft. density fiberglass may be used in lieu of the sponge.
Seals shall be type SWS as manufactured by Mason Industries, Inc.
7. Pipe Anchors:
a. Specification “N”: Vibration isolator manufacturer shall provide an alldirectional
acoustical pipe anchor, consisting of a telescopic arrangement
of two sizes of steel tubing separated by a minimum half inch thickness of
heavy duty neoprene and duck or neoprene isolation material. Vertical
restraints shall be provided by similar material arranged to prevent
vertical travel in either direction. Allowable loads on the isolation material
shall 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.
8. Horizontal Thrust Restraints:
a. Specification “X”: Air handling equipment shall be protected against
excessive displacement which might result from high air thrusts in relation
to the equipment weight. The horizontal thrust restraint shall consist of a
spring element in series with a neoprene pad as described in Specification
B, with the same deflection as specified for the mountings or hangers.
The spring element shall be contained within a steel frame and designed
so it can be preset for thrust at the factory and adjusted in the field to
allow for a maximum of ¼” movement at start and stop. The assembly
shall be furnished with one rod and angle brackets for attachment to both
the equipment and ductwork or the equipment and the structure.
Horizontal restraints shall be attached at the centerline of thrust and
symmetrically on either side of the unit. Horizontal thrust restraints shall
be type WB as manufactured by Mason Industries, Inc.
9. Curb-Mounted Aluminum Bases:
a. Specification “Y”: Curb-mounted rooftop equipment shall be mounted on
vibration isolation bases that fit over the roof curb and under the isolated
equipment. The extruded aluminum top member shall overlap the bottom
member to provide water runoff independent of the seal. The aluminum
members shall house cadmium plated springs having a 1” minimum
deflection with 50% additional travel to solid. Spring diameters shall be
no less than 0.8 of the spring height at rated load. Wind resistance shall
be provided by means of resilient snubbers in the corners with a minimum
clearance of ¼” so as not to interfere with the spring action except in high
winds. The weather seal shall consist of continuous closed cell sponge
materials both above and below the base and a waterproof flexible
ductlike EPDM connection joining the outside perimeter of the aluminum
23 0548 - 7 VIBRATION AND SEISMIC
CONTROLS FOR HVAC PIPING
AND EQUIPMENT