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Each ring shall be bent while cold to cylindrical form to
the extreme ends of the plate. The bending shall be done entirely
by machine and heating or hammering is prohibited.
Reg. 103
SHELLS, ANGLE RINGS, BUTT STRAPS, ETC.
Position of Longitudinal Seams
Each ring of plate forming the shell, barrel or drum shell,
where practicable, be in one piece and have its longitudinal
seam well out of line with those of the adjoining rings. In
Lancashire, Cornish, and other types of boilers, where parts
of the shell are exposed to flame, the longitudinal seams shall,
where practicable, be in the steam space, arranged alternately
on each side of the crown and clear of the brick work.
Reg. 104
SHELLS, ANGLE RINGS, BUTT STRAPS, ETC.
Circumferential and End Seams
The calculated efficiencies of circumferential joints based
on the thickness of plate determined by Equation1, shall be
not less than 38 per cent for joints connecting end plates with
cylindrical shells or 42 per cent for intermediate joints. In
no case, however, shall the efficiency of an intermediate joint
be less than 50 per cent of that of the longitudinal joints.
Where the shell plate thickness exceeds 11/16 inch the intermediate
circumferential joints shall be double riveted. |
