5.1.1 The minimum
wall thickness, t, of standpipes and branches is to be
not less than the greater of the two values determined by the following
formulae, making such additions as may be necessary on account of
bending, static loads and vibration:
|
t
|
= |
|
|
t
|
= |
|
t, p, D
o and
σ are as defined in Pt 5, Ch 9, 1.2 Definition of symbols.
If the second formula applies, the thickness need only be maintained
for a length, L, from the outside surface of the vessel,
but need not extend past the first connection, butt weld or flange,
where:
|
L
|
= |
|