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Reg. 207
STAYS
Gusset Stays
The maximum working pressure for gusset stays shall be calculated
by the following formula :
| W. P. = |
9000 x C
|
Eqn.(42) |
| A |
C the co-efficient, is the number representing the least of
the following: -
1) N1 x A1,
2) N2 x A2 x 1.875,
3) N3 x A3 x 1.875
4) N4 x A4
5) ( G - N2 D2 ) x ( t - 2 ) x .037,
6) ( G1 - D3 ) x ( t - 2 ) x .037
N1, N2, N3, N4, D1,
D2, D3, D4 and A1,
A2, A3, A4 are respectively
the numbers, diameters and sectional areas of the rivets in
the joints of each gusset stay, only rivets in the supported
area, to be considered effective, the order of the joints being,
(1) angles to end plate, (2) end plate angle to gusset, (3)
shell angles to gusset, and (4) angles to shell.
G is the depth in inches of gusset plate measured through the
line of rivet attaching it to the end plate angles.
G1 is the depth in inches of gusset plate measured normal to
the slant edge of plate through the rivet nearest to the end
plate in the joint attaching gusset plate to shell angles.
t is the thickness of the gusset plate in 32nds of an inch.
A is the area in square inches of flat plate supported by the
gusset edge of plate through the rivet nearest to the end plate
in the joint attaching as follows :-
(a) The margins allowed under flat plate regulations for shell and
furnace shall be marked on end plates and the lengths of the
centre lines of gussets between them measured, also the distance
between each pair of gusset lines from the middle of the smaller
in a direction normal to the greater. If L and L1, be the length
of two adjacent gusset lines and if the distance between them
be W, the area contained by the gusset lines and the shell and
furnace margins lines may be apportioned between the stays thus
:
| W ( 3L + L1 ) |
= Portion of area in square inches, apportioned to
L line gusset
|
Eqn.(43) |
| 8 |
| W ( 3L1 + L ) |
= Portion of area in square inches, apportioned to
L1, line gusset
|
Eqn.(44) |
| 8 |
(b) The portion of the area on the other side of each gusset
line shall except when of triangular form, be found in like
manner and its amount added to that already found to form the
total.
(c) For the triangular portions in the wing spaces the area
shall be taken as half the product of the length of gusset line
into the perpendicular distance between it and the intersecting
point where the marginal curves meet. |
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