| a) |
Riveted on flanges shall only
be used for pipes of 7” bore and above and for a
maximum pressure 350 lbs. per sq. in. and/or a maximum
temperature of 750°F. |
| b) |
The shear stress in the rivets shall not exceed 6000
lbs. per sq. in. when calculated by the following formula:-
where,
Sr = the shear stress in the rivets in lbs. per sq.
in.
Ao = cross sectional area, calculated on outside diameter
of pipe in sq. inches.
P = Working pressure in lbs. per sq. in.
N = number of rivets,
A = Area of one rivet hole in sq. in.
|
| c) |
The stress in the pipe shall not exceed the specified
in Table 3 when calculated by the following formula:-
| Sp = |
Ao x P |
Eqn.(95) |
| ( Ao - A1 ) - ( N x d
x t ) |
where,
Sp = the stress in the pipe in lb. per sq. in.
Ao = P and N have the values given above, and
A1 = cross sectional area, calculated on inside diameter
of pipe in sq. inches.
d = diameter of rivet hole in inches.
t = minimum thickness of pipe in inches. |
| d) |
The flange hub thickness shall
not be less than 0.2 in thicker than the minimum thickness
of the pipe. |
| e) |
The distance from the edge
of the hub to the centre line of the rivets shall be not
less than one and a half times the diameter of the rivet
hole. |
| f) |
The pipes shall first be properly
expanded into the flanges or alternatively the flanges
shrunk on to the pipes, the rivet holes shall then be
drilled through the pipe and hub, and the holes afterwards
countersunk to remove burrs. |
| g) |
After riveting the flange hub
shall be fullered at the back. |
