Page 220 - Pressure Vessel Design Manual

198 Pressure Vessel Design Manual

e Between chairs.

M,=greater of M, or My from Table 3-36

Figure 3-73. Top plate dimensions and loadings.
Top Plate or Ring (Type 3 or 4)

Washers
e Minimum required height of anchor chair (Type 3 or 4).
7.296d
hmin = - - 7
< 18in.
H
e Minimum required thickness of top plate of anchor chair.

tc = ,/x(0.375b - 0.22db) X
Fbe

Top plate is assumed as a beam, e x A with partially fmed
ends and a portion of the total anchor bolt force P/3,
distributed along part of the span. (See Figure 3-73.)
Figure 3-74. Compression plate dimensions.
e Bending moment, M,, in top ring (Type 4).

b
- e Minimum required thickness of top ring (Type 4).
e
y1 = (see Table 3-37)
y2 = (see Table 3-37)
1. If a = e/2 and b/e 1, My governs
Gussets
~~~ ~ ~ ~
e Type 2. Assume each gusset shares load with each adjoin-
ing gusset. The uniform load on the base is fc, and the area
2. If a # U2 but b/l> 1, My governs supported by each gusset is e x b. Therefore the load on
the gusset is
P,=f,tb

Thickness required is
3. If b/t< 1, invert b/.t and rotate axis X-X and Y-Y 90" Pi(6a - 2C)
' Fb12
=
e Type 3 or 4.

3
t -- P > - in.
g- 18,000l 8