4.1.1 As an alternative
to the formula in Pt 5, Ch 9, 3.1 Minimum thickness 3.1.1 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:
|
t
|
= |
|
t, p and R
i are
as defined in Pt 5, Ch 9, 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.
|
4.1.2 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.
4.1.3 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.
4.1.4 Ends convex
to pressure are not to be used for vessels exceeding 610 mm internal
diameter.
4.1.5 Where the
end is provided with a flanged manhole, the thickness of the end,
in mm, determined by Pt 5, Ch 9, 4.1 Minimum thickness 4.1.1, 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:
|
H
|
= |
|
|
t
1
|
= |
required thickness of the plate, in mm |
|
H
|
= |
depth
of flange, in mm |
|
W
|
= |
minor
axis of the manhole, in mm. |