5.1.1 As
an alternative to the formula in Pt 5, Ch 11, 4.1 Minimum thickness 4.1.1,
for Class 3 vessels only, the minimum thickness, t, of
a torispherical unstayed end dished from plate and having pressure
on the concave or convex side is to be determined by the following
formula:
where
|
t, p, and R
i
|
= |
are as defined in Pt 5, Ch 11, 1.2 Definition of symbols
|
|
C
|
= |
2,57
for ends concave to pressure |
|
|
= |
1,65 for ends convex
to pressure |
|
S
|
= |
specified
minimum tensile strength of plate, in N/mm2, which should
be not less than 410 N/mm2.
|
5.1.2 The
inside radius of curvature, R
i, of the end
plate is to be not greater than the external diameter of the cylinder
to which it is attached.
5.1.3 The
inside knuckle radius, r
i, of the arc joining
the cylindrical flange to the spherical surface of the end is to be
not less than four times the thickness of the end plate, and in no
case less than 65 mm.
5.1.4 Ends
convex to pressure are not to be used for vessels exceeding 610 mm
internal diameter.
5.1.5 Where
the end is provided with a flanged manhole, the thickness of the end,
in mm, determined by Pt 5, Ch 11, 5.1 Minimum thickness 5.1.1,
is to be increased by 3 mm, and the total depth, H, of
the manhole flange, measured from the outer surface of the plate on
the minor axis, is to be not less than :
where
|
t
1
|
= |
required thickness of the plate, in mm |
|
H
|
= |
depth
of flange, in mm |
|
W
|
= |
minor
axis of the manhole, in mm. |