Flat End Plates
||The plates of boilers shall
preferably be in one piece made from one rolled plate.
Alternatively, the end plates may be built up from two
pieces by riveting or by fusion butt-welding. In the latter
case, the line of weld shall be parallel to the horizontal
axis of the boiler and the entire plate after flanging
shall be subjected to stress relieving and the weld shall
||The peripheral flanging of
end plates shall be done by machine. Such flanging shall
preferably be done in one operation, but where this is
impracticable sectional or creep machine flanging may
be permitted, provided that the plate is worked at a suitable
temperature, and the plate is heated to an adequate distance
beyond the portion under immediate treatment.
||In the construction of unfired
boilers when the dished ends do not form a part of the
heating surface, cold spun dished ends conforming to IS:
2825 may be used.
||Care must be taken to see that
the flanges are circular and of good surface, free from
local irregularities, and that they are parallel and square
with the flat part of the plate. For the purpose of relieving
internal stresses, all plates which have been flanged
or locally heated shall afterwards be efficiently annealed
unless during the last stage of manufacture they have
been uniformly heated throughout.
||Flat portions of end plates,
on completion of all flanging and machining operations,
shall be flat and free from set or distortion.