Page 152 - Pressure Vessel Design Manual

130 Pressure Vessel Design Manual

Table 3-10
Vertical Load on Legs, F,
I
Leg1 Case 1 case2 Leg Case 1 case 2

6 Legs
FD-FL 1 FD-0.951 FL
2 -0.588FL
3 0
4 +0.588FL
5 +0.951 FL
6 +0.951 FL
7 +0.588FL
8 Legs 8 0
9 +0.588FL
FD-FL FD-0.924FL 10 +0.951 FL
-0.707F~ -0.383
0 12 Legs
+0.707FL
+FL 1
-0.707FL +0.383 2 - 0.866FL -0.707
0 -0.383 3 -0.5FL -0.259
1 +0.707FL -0.924 4 0 +0.259
5 +0.5FL t0.707
16 Legs 6 +0.866FL +0.966
7 +FL +0.966
1 FD-FL ,-0.924 8 +0.866FL +0.707
2 -0.924FL -0.382 9 +0.5FL +0.259
3 -0.707FL +0.556 10 0 -0.259
4 -0.383F~ +0.195 11 -0.5FL -0.707
5 0 +0.195 12
6 +0.383FL +0.556
7 +0.707F~ +OB31
8 +0.924F~ +0.981
9 +FL +0.981
10 -0.924FL +OB31
11 +0.707FL +0.556
12 -0.383F~ +0.195
13 0 -0.195
14 -0.383F~ -0.556
15 -0.707FL -0.831
16 -0.924FL -0.981

Notes 4. Legs may be made of pipe, channel, angle, rectangular
tubing, or beam sections.
1. Legs longer than 7ft should be cross-braced. 5. This procedure assumes a one-mass bending structure
2. Do not use legs to support vessels where high vibration, which is not technically correct for tall vessels. Tall
shock, or cyclic service is anticipated. towers would have distributed masses and should be
3. Select legs that give maximum strength for minimum designed independently of support structure, i.e., legs.
weight for most efficient design. These sections will
also distribute local loads over a larger portion of the
shell.