Page 238 - Pressure Vessel Design Manual

216 Pressure Vessel Design Manual
a Required moment of inerfia, I,.
L, = JL2 + (RL - R,)'

Ring only Ring-shell
LStl LCtCl
AT=--+- + A,
2 2

Notes

1. Cone-cylinder intersections are areas of high discon-
f, = P,N + Vz tan a
tinuity stresses. For this reason the ASME Code
requires reinforcement at each junction and limits
angle a to 30" unless a special dscontinuity analysis
B=- fSd0 is performed. This procedure enables the designer to
AT
take into account combinations of loads, pressures,
A= using calculated value of B, determine A from the temperatures, and materials for cones where 01 is
applicable material chart of ASME Code, Section less than or equal to 30" without performing a discon-
11. For values of A falling to the left of the material/ tinuity analysis and fulfill all code requirements.
temperature line: 2. The design may be checked unpressurized with the
effects of weight, wind, or earthquake by entering P,
2B as 0 in the design tables. This condition may govern
A=-
ES for the compression side.

PROCEDURE 4-3
STRESSES AT CIRCUMFERENTIAL RING STIFFENERS 13-61

Notation M =bending moment in shell, in.-lb
Mb = longitudinal bending moment, in.-lb
P = pressure; (+) internal pressure, (-) external pres- F = discontinuity force, Ib/in.
sure, psi N = axial force, Ib/in.
us =Poisson's ratio, shell, 0.3 for steel W, =operating weight of vessel above ring elevation,
a, =coefficient of thermal expansion of ring, in./in.PF lb/in.
a, =coefficient of thermal expansion of shell, in./in.PF W1-7 = radial deflections, in.
E, = modulus of elasticity, ring, psi A, =cross-sectional area of ring, in.2
E, = modulus of elasticity, shell, psi a, =longitudinal stress, shell, psi
ATr = temperature difference between 70°F and design CT+ =circumferential stress, shell, psi
temperature, ring, "F
ATs =temperature difference between 70°F and design CT+~ =circumferential stress, ring, psi
temperature, shell, "F B = damping factor