Reg. 538, Reg. 539 a, Reg.
539 b, Reg. 540, Reg. 541
Where covered electrodes are used they shall comply
with the requirements of Regulations
94 to 98 save
in the case of the weld metal as deposited, where the
tensile strength shall not be less than the lower limit
specified for the plate.
Reg. 539 a
Plain and Stay Tubes
|Tubes shall comply so far as
may be with the provisions of Regulations
36 to 63.
For plain tubes subjected to external pressure
steel tubes as provided in the Regulations
64 to 67 may
Reg. 539 b
Seamless Steel Crosstubes and Uptake Tubes
Construction and Workmanship
The manufacturer shall supply the Inspecting Authority
with a fully dimensioned sectional drawing showing in
full detail the construction of the boiler for approval
before putting the work in hand.
Full details including dimensions of plate preparation
for the longitudinal and circumferential seams shall
also be shown on the drawing.
Fully dimensioned sketches showing in details the attachment
for stand-pipes, branch pipes and seatings, the position
of these attachments relative to the longitudinal and
circumferential seams and other opening shall also be
given in the drawing.
Preparation of Plates
The edges of all plates, shall be machined or flame-cut
by machine. Gusset plates may be sheared except on those
edges, which are to be welded.
Plates which are to flame-cut by machine without subsequent
heat- treatment, grinding or machining, shall not have
a carbon content higher than 0.26 per cent. Where the
carbon content exceeds 0.26 per cent, heat-treatment
grinding or machining shall be carried out.
The edges of all plates shall have a smooth finish.
The welding edges of all plates shall be cleaned to
a smooth metallic surface and shall be free of rust, oil
or other foreign matter before welding is commenced.
The surfaces of the plates at the longitudinal and/or
circumferential seams shall at no part be out of alignment
with one another by more than 10 per cent of the plate
thickness but in no case shall misalignment exceed 1/8
inch for longitudinal seams or 3/16 inch for circumferential