Calculation of Wasted Shell
||When any part is wasted and the Inspector
is doubtful of its fitness for the pressure, he shall
cause one or more small holes to be bored and from them
ascertain the average thickness of the parts from which
he can satisfy himself by calculation in accordance with
the formula applicable to the part. Such gaugings and
calculations he shall enter in the Memorandum of Inspection
||In making calculations for a wasted part
of a boiler shell, e.g., along the line of seating blocks
of a Lancashire boiler, the Inspector shall use the following
|W. P. =
||2 t X
|D X F
t = thickness of wasted plate, where thinnest.
S = minimum tensile strength of material of shell in lbs.
per sq. in.
D = internal diameter of shell in inches.
F = factor of safety, which shall not be less than 4.