TABLE 3A
Vibration Isolator Types and Minimum Static Deflection
(MSD, inches) for 4-8 inch slab on grade and column supported.
Column
Slab on earth
31-40 feet
41-50 feet
Spacing
and 0-30 feet
Equipment
Type
MSD
Type
MSD
Type
MSD
_________
(Note (1))
(Note (1))
(Note (1))
High Pressure Fans
HR recommended for minimizing undesirable
(Over 6 Inch
thrust effects
Water-Column
Static Pressure)
and Other
Machineries
Producing Thrust
(Note (2))
Internal
Engines and
Engine
Driven Equip
750 rpm and
S
1.5
S
2.5
S
3.5
over
Dimmer Banks and
Up to 1000
NM
0.35
NM
0.35
S
3.5
lbs.
Over 1000 lbs.
SV
1.0
SV
1.0
SV
1.0
NOTES: (1)
Equipment Vibration Isolation Schedule Designations
(Hyphenated designations are combinations of the following:)
B
- Welded structural steel bases.
H
- Spring isolators (suspended equipment and piping). Where
required, provide with adjustable preloading devices.
HR - Thrust restraints
I
- Concrete inertia bases with steel forms.
NM - Neoprene mounts.
NP - Neoprene pads.
R
- Structural steel rail for equipment mounts.
S
- Freestanding spring isolators (floor-mounted equipment).
SV - Freestanding spring isolators (floor-mounted equipment).
SECTION 15070N
Page 39
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