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Reg. 115, Reg. 116, Reg. 117
END PLATES
End Plates in steam spaces
When the end plates of boilers situated in the steam space
are liable to contact with hot gases, the end plates shall be
efficiently shielded from such contact.
Reg. 116
END PLATES
Hemispherical Crowns
| a) |
All segments shall be pressed
in one heat to correct curvature. The adjacent plates
shall be closely at the seams and wherever possible at
the junction of two seams the plates shall be machined
down to provide a fair surface to the joint. If the thinning
is done by heating and hammering the plate shall be subsequently
annealed. |
| b) |
The cylindrical portion of
the crown shall be tangential to the hemispherical portion
and fit truly to the shell. |
Reg. 117
END PLATES
Dished End and Crown Plates
| a) |
The dished end plates of boilers
shall preferably be in one piece made from one-rolled
plate. If this is impracticable owing to the large diameter,
the dished end plate may be made from two plates fusion
butt welded together and in such cases the requirements
of stress relieving and radiographic examination as provided
for in Regulation 113 shall apply and the line of weld
shall be parallel to the horizontal axis of the boiler.
The inside radius to which a plate is dished shall not
be greater than the external diameter of the shell to
which it is attached, except in the case of Lancashire
and Cornish boilers when the radius shall not exceed 1½
times the diameter of the shell. |
| b) |
The inside radius of curvature
of the flanges to the shell or firebox shall not be less
than four times the thickness of the crown or end plate
and in no case less than 2½ inches. |
| c) |
The inside radius of curvature
to uptakes shall be not less than twice the thickness
of the crown plate and in no case less than 1 inch. |
| d) |
Bunged mouth-pieces may be
welded on to end plates in place of the orthodox flanging
for the attachment of furnace tubes. Such welding shall
comply with provisions of Regulation
125. |
| e) |
Manhole frames may be similarly
welded on the front end plates, and will be subject to
provisions of Regulation 125. |
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