|
The working pressure of cylindrical shells with fursion
welded seams shall be calculated from the following
formula:-
| W.P. = |
(t-2) x S x C |
Equation (99)
|
| D |
Where,
t = thickness of shell plate in thirty-seconds of an
inch.
D = internal diameter of shell in inches.
S = Ultimate tensile stress in tons per square inch.
C = 32 for Class I boilers.
C = 27 for Class II boilers.
In no case the thickness of cylindrical shells with
fusion welded seams be less than those given in table
below:-
Minimum
thickness for Fusion Welded Shells
| Class |
Internal diameter inches |
Minimum thickness inches |
| II |
Up to and including 24 |
¼ |
| Over 24 up to and including
36 |
5/16 |
| Over 36 |
3/8 |
In no case shall the factor of safety of the cylindrical
shell and ends be less than 4.
|
