K465i Operations and Maintenance
P/N 1212831 Rev C
Page 2-19
Copyright
©
2012
Veeco Instruments, Inc. Confidential
All Rights Reserved
The bracket location for Reactor Exhaust Assembly is identified on drawing 1093563
SEISMIC.
The center of gravity is located 21” above the floor.
Weight of the major sub assemblies: Total W
p
=2696 lb
Horizontal load per SEMI S2-0200:
F
p
=F
x
= F
y
=0.94W
p
= 2696 x 0.94 =2534.2 lb
Where:
The horizontal loadings of 0.94 were based on following assumptions for factors in formula
32-2 in Section 1632.2 of the 1997 Uniform Building Code (UBC):
a
p
= 1.0 (i.e. treat equipment as rigid structure)
C
a
= 0.44 (i.e. seismic zone 4)
I
p
= 1.5 (HPM equipment)
h
r
/h
p
= 0.5 (equipment installed halfway between grade elevation and roof elevation)
R
p
= 1.5 (shallow anchor bolts).
Horizontal force acts as shear force on the floor fasteners.
The shear force:
lb
n
F
F
p
s
18
.
211
12
2
.
2534
Where:
n=12 the number of anchor bolts
Recommended anchors are ¾” diameter expansion bolts ASTM A325 or F1852.
Shear stress
psi
S
psi
R
psi
A
F
s
w
u
b
s
16000
48000
28
.
632
334
.
0
18
.
211
Where:
A
b
=0.334
2
in
-area of cross-section
R
u
= 48000psi - ultimate shear strength for conditions when thread included in shear plane.
S
w
=16000psi- allowable shear working stress
psi
f
R
S
s
u
w
16000
3
48000
f
s
=3 –safety factor for applications where reliable materials to be used under difficult
loading and environmental conditions.
(Source: Machinery’s Handbook 26 p.199-200)
Overturning force derived from the sum of the moments of the reactions on the system
about the line through the legs on Y= 0.00 coordinate.
lb
R
CG
F
T
y
p
602
3
.
45
6
.
21
9
.
1198
98
.
20
2
.
2534
3
.
45
6
.
21
1
