STAND PIPES, PADS ETC.
Seating for Mountings
For pressures not exceeding 125 lbs. per sq. inch mountings
with the screwed ends not exceeding 1 inch S.P.T. may be used;
the screwed portion of any such mounting being an integral part
thereof and the thickness at the bottom of the thread being
not less than 3/16.
The mountings may be screwed:-
||Directly into the boiler shell
plate, nuts being fitted on the waterside or
||Into steel distance pieces
the length of thread engaged being in no case less than
the bore of the mounting plus ¼ inch.