7.1.1 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 vibrations:
where t, p, Do, c and σ are defined
in Vol 2, Pt 8, Ch 2, 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:
7.1.2 In no
case need the wall thickness exceed the minimum shell thickness as
required by Vol 2, Pt 8, Ch 2, 2.1 Minimum thickness, Vol 2, Pt 8, Ch 2, 3.1 Minimum thickness or Vol 2, Pt 8, Ch 2, 4.1 Minimum thickness as applicable.