 |
| |
Reg. 591 c, Reg. 591 d, Reg. 591 e
Link stays
|
| |
|
Link stays shall be so arranged that the angle “V”
(Fig. XII/83)
is not less than 60° and the dimensions
shall be such that the stress in the stay at its weakest
part does not exceed one-seventh of the minimum tensile
stress of the plate used.
|
Reg. 591 d
Anchor plates angles, link pins and the
like
members
|
The strength of anchor plates, angles and link pins
calculated at the weakest section shall be as follows:-
| (i) |
Link pins shall be so designed that the shear
stress does not exceed 8,000 pounds per square
inch, the strength of pins in double shear being
taken as 1.875 times the strength of pins in single
shear.
|
|
(ii)
|
Anchor plates or angles
shall be so designed that the calculated stress
does not exceed one-seventh of the minimum tensile
stress of the material used, but in no case shall
the thickness be less than seven-eighth of the thickness
of the shell plate with a minimum of ½ inch,
nor the length of the portion attached to the end
plate be less than the distance between the lines
of end to shell flat margin and the breathing space
line around the flues or tube nests. |
|
Reg. 591 e
Weld attachment
|
Where gusset plates, anchor plates or angles are welded
to the shell and/or end plates, the attachment shall
be by means of continuous fillet welds on each side
or by butt welds prepared in accordance with paragraph
2, details 1, m, n, or p of Appendix A of this Chapter.
The welds shall be of such dimensions that the stress
calculated on an area equal to the effective length
of the weld multiplied by the effective throat thickness
shall not exceed that permitted for the parent metal
multiplied by the appropriate weld factor in Table
XII/7
The effective length of a weld shall be taken as that
length of weld which is of the specified size throughout.
For open-ended fillet welds the effective length shall
be the overall length less twice the weld size.
For the purpose of stress calculation the effective
throat thickness of a butt weld shall be taken as the
thickness of the gusset or anchor plate and the effective
throat thickness of fillet weld shall be taken as 0.7
of the fillet size. For compound welds the effective
throat thickness shall be the sum of those of the constituent
parts.
TABLE XII/7
Weld Attachments |
|
Form of weld
|
Weld factor
|
| |
Not stress relieved |
Stress relieved |
| Single J or bevel butt-welds (with
or without superimposed fillet. |
Unsealed
Sealed |
0.35
0.60 |
0.45
0.70 |
| Double J or bevel butt-welds [with
or without super-imposed fillet(s)] |
|
0.60 |
0.70 |
| Double fillet welds |
|
0.55 |
0.65 |
|
|
|
