substitution request - Alliance Construction Solutions

Project No.: 10145
550 15 th Street Dual Brand Hotel
03/16/2012
at rated load. Springs shall have a minimum additional travel to solid
equal to 50% of the rated deflection. Submittals shall include spring
diameters, deflections, compressed spring height and solid spring height.
Mountings shall be type SLF as manufactured by Mason Industries, Inc.
c. Specification “C”: Equipment with operating weight different from the
installed weight such as chillers, boilers, etc. and equipment exposed to
the wind such as cooling towers shall be mounted on spring mountings as
described in engineering Specification B, except a housing shall be used
that includes vertical limit stops to prevent spring extension when weight is
removed. The housing shall serve as blocking during erection, and
cooling tower mounts shall be located between the supporting steel and
roof or the grillage and dunnage as shown on the drawings. The
installed and operating heights shall be the same. A minimum clearance
of ½” 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. Mountings used
out-of-doors shall be hot dipped galvanized. Mountings shall be type SLR
as manufactured by Mason Industries, Inc.
2. Hangers:
a. Specification “D”: Vibration hangers shall contain a steel spring, located
in a neoprene cup manufactured with a grommet to prevent shortcircuiting
of hanger rod, and 0.3” deflection neoprene element in series.
The spring shall be color coded for ease of identification. The neoprene
element shall be molded with a rod isolation bushing that passes through
the hanger box. Spring diameters and hanger box lower hole sizes shall
be large enough to permit the hanger rod to swing through a 30° arc
before contacting the hole and short-circuiting the spring. Springs shall
have a minimum additional travel to solid equal to 50% of the rated
deflection. Submittals shall include a scale drawing of the hanger
showing the 30° capability. Hangers shall be type 30N as manufactured
by Mason Industries, Inc.
b. Specification “D1”: Vibration hangers shall contain a 0.3” deflection
neoprene element. The neoprene element shall be molded with a rod
isolation bushing that passes through the hanger box. Hangers shall be
type HD as manufactured by Mason Industries, Inc.
c. Specification “E”: Vibration hangers shall be as described in engineering
Specification D, except they shall be precompressed to the rated deflection
so as 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. Hangers shall be type PC30N as manufactured by Mason
Industries, Inc.
d. Specification “F”: Vibration hangers shall contain a steel spring located in
a neoprene cup manufactured with a grommet to prevent short-circuiting
of the hanger rod. The cup shall contain a steel washer designed to
properly distribute the load on the neoprene and prevent its extrusion.
Spring diameters and hanger box lower hole sizes shall be large enough
to permit the hanger rod to swing through a 30° arc before contacting the
hole and short-circuiting the spring. Springs shall have a minimum
additional travel to solid equal to 50% of the rated deflection. Hangers
shall be provided with an eye bolt on the spring end and provision to
22 0548 - 4 VIBRATION AND SEISMIC
CONTROLS FOR PLUMBING
PIPING AND EQUIPMENT