||Gusset stays shall be so arranged
as to allow sufficient breathing space around furnace
connections and tube nests.
||For Lancashire boilers the
proportions shown in the table below are recommended for
the portion of the end plates above the furnaces and flues.
|Thickness of End Plates
shows the breathing
space recommended for the following conditions: Flat end,
furnace or flues flanged for attachment to end plate,
furnaces and flues formed with Adamson flanged seams.
shows similar conditions
to Fig. 8 except that the end plate is flanged outwards
for the furnace or flue ring connection, the breathing
spaces allowed being 1 inch more than those for the same
thickness of plate in Fig.8.
||Where a corrugated section
not less than 6 feet long is included in each internal
flue of a Lancashire boiler, the dimensions given in the
table above may be reduced by approximately 1½
||It is recommended that the
breathing space below the furnaces and flues shall be
approximately one half the dimensions given in the table
above. Whereas it is desired to use any other arrangement
which gives a greater or less degree of flexibility, the
amount of breathing space shall be specially considered
and modified as the necessity of the case requires.
||For gusset stays above tube
nests, as fitted in waste heat boilers without internal
furnaces, a breathing space of 8 inches from the centre
line of the top tubes to the centre of the toe rivets
of the gusset angles is recommended (see Fig.