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Reg. 235, Reg. 236,
Reg. 237 , Reg. 238, Reg. 239
SEAMLESS FORGED DRUMS
Manufacture |
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a)
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Carbon
Steel for seamless forged Drums shall be made by the open-hearth
or electric furnace or basic oxygen process or any other
process which gives steel having equivalent properties. |
| b) |
Forging
which may have integral ends, ends closed by means of
dished plates, open ends for multi-joints drums or any
combination of these shall be made from solid cast ingot
which is punched, bored or trepanned, or from a hollow
cast ingot and shall comply entirely with the relevant
requirements of Chapter
II. |
Reg. 236
Chemical Analysis
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The steel shall not contain more than 0.050 per cent
of sulphur or of phosphorus.
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Reg. 237
Freedom from defects
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The drum shall be free from surface defects and shall
be machined to the prescribed dimensions.
Defects in
forgings shall not be repaired without the previous
sanction of the Inspecting Officer.
Where not machined, the forgings shall be workman like
surfaces as normally obtained by hot working. Provided
that the minimum specified thickness is maintained,
minor surface defects may be admitted and other defects
removed by mechanical means so as to achieve a smooth
surface. Surface defects may be repaired, by welding
only, with the approval of the Inspecting Authority
provided that the drum is stress relieved after welding,
wherever necessary.
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Reg. 238
Heat Treatment
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Each drum shall be efficiently heat treated:
| a) |
At various stages during
manufacture, as required |
| b) |
On completion of the
forging process but prior to the hydraulic test. |
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Reg. 239
Mechanical Tests
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Material shall comply with the mechanical tests herein
specified.
Sufficient material shall be left on the open end or
ends of each forging to enable tangential test pieces
to be taken. These tests shall consist of not less than
one tensile and one bend test from each open end. In
the case of drums with open ends the test material shall
not be parted off before heat treatment. If the drums
are closed in at the ends the test rings shall be parted
off immediately before this operation; subsequently
the test rings and the forging shall be similarly, and
simultaneously heat treated in the same furnace.
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