|Reg. 130, Reg. 131, Reg. 132
Bar stays shall not be welded at any part. They shall preferably
have plus threads, the ends of the stays being upset or the
middle portion being reduced for this purpose. Stay bars which
have been worked in the fire shall be subsequently annealed.
||Longitudinal and similar solid
screwed stays shall be efficiently secured with nuts at
each end and not merely revited over. Where they are over
12 feet in length, they shall be supported at intervals
of 6 ft. along its length.
||Where the stay is screwed through
both plates, the stay and holes shall have a continuous
thread and fitted with nuts and washers on the outside.
Where the stay passes through clearing holes an internal
nut and washer shall also be fitted. Where the stay is
not normal to the surface of the plate the washer shall
be shaped so as to form a true surface for the nuts or
a knuckle joint may be fitted.
||In vertical boilers the stays
shall either be screwed into both crown plates or screwed
into the furnace crown plate and passed through clearing
holes in the shell crown plate.
Nuts and Washers for Stays
||The washers shall be at least
2½ times the diameter of the threaded portion of
the stay and not less than ¼ inch in thickness.
||The thickness of the external
nuts shall be at least equal to the diameter of the threaded
portion of the stay. Where bar stays pass through clearing
holes in end plates, internal nuts of a thickness not
less than two-thirds of the diameter of the threaded portion
of the stay shall be fitted.