Improvements in and relating to the Manufacture of Tubes or Flues.
Year: 1889

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to the Manufacture of Tubes or Flues.
I, WARREN EDEN HILL, of 438 Washington Avenue, in the City of Brooklyn,
County of Kings, State of New York, United States of America, Engineer, do
hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
This invention relates to the manufacture of tubes or pipes having flanged or
headed ends; that is, having laterally projecting flanges at either or both ends by
which the tubes may be joined together or secured in place in the structure in which
they are used.
Such tubes are largely used as furnace shells or flues for steam boilers, and I shall
describe my invention as embodied in a corrugated furnace flue, though it will be
obvious that the invention includes other forms of flanged tubes or pipes.
It is to be understood that in securing a flue or other like tube in a boiler structure,
flanges or like means must be formed between the end of the tube and the boiler plates
by which to secure the tubes to the boiler. To this end, it has been customary to
forge or otherwise expand one end of the tube or flue into the form of a flange, which
served as a means to rivet the flue to the boiler plates or to front plate or plates of the
furnace.
It is obvious, however, that in thus forming a flange on the end of the flue, the
metal will be reduced in thickness; and this flanging can be practically done only for
purposes where a small or narrow flange will suffice. It is, however, desirable, in
many cases where flues or tubes and pipes are used, to employ forms thereof having
flanges much wider in lateral extent than would be possible to forge or expand from
the body of the tube, without reducing the stock to such an extent that the flange
would not have the requisite strength compared with the body of the tube. Thus,
with boiler or furnace pipes, it is desirable to form integral with the body of the flue
the head or plate that is to form a part of or is to connect it to the fire chamber or
boiler shell.
My invention consists, therefore, first, of a headed or flanged tube or flue, composed
of a cylindrical body, a plate forming the head or flange provided with a circular
flanged opening, the flange of said opening being welded to the end of the cylindrical
body.
Secondly. The invention consists in the method of producing a headed or flanged
tube or flue, that is, in forming a circular flange around an opening in a plate adapted
to serve as a head to the pipe and welding the flange of such opening to the end of
the pipe.
In the accompanying drawings
Figure 1 is a perspective view of a corrugated tube provided with one form of
flange-head shaped and joined to the tube in conformity with my invention.
Figures 2 and 3 are detail sectional views illustrating the method of welding the
head to the tube.
Figure 4 is a central longitudinal section of the tube on line x-x of Figure 5.
Figure 5 is a plan view of the structure of Figure 4 unsectioned.
In these views, A represents the corrugated tube. It is made by forming a sheet
into cylindrical form, and then circumferentially corrugating the same between suitable
rolls.
This tube may be finished with a plain end B (Figure 2) or with a corrugated
end C (Figure 3). D is the flange head of the tube, this head being usually the con-
necting plate or part of the structure to which the tube is to be attached. In the
present instance, the tube A is one of a pair of furnace tubes which enter the combus-
tion chamber, the other flue and its head being indicated by dotted lines as seen in
Figure 1.

page_text: The central portion of the head D is first properly cut out so as to form an opening
somewhat smaller than the diameter of the fluc at its inner end or the end to which
the head is to be attached. The edge of this opening is then bent up or flanged, by
pressing or forging, at right angles to the body of the plate. Such flange is
represented by letter E; in Figure 1 it is shown as a plain flange, in Figure 2 it is
shown as being shaped to form a part of the last corrugation of the flue. Another
flange may be formed on this head if requisite by which to secure the head to other
parts of the combustion chamber or boiler.
When the head has thus been prepared, it is then welded to the flue and thereby
becomes an integral part thereof. The parts to be welded together may be scarfed so
as to partially over reach each other, thereby producing a lap weld, as seen at G
Figure 2 but the particular method of welding is not essential as the head may be
otherwise attached to the tube by various other forms of welds.
The flanged or headed flue thus produced is a much stronger structure than the
flue heretofore produced and having the same lateral extent of flange or head, and it
obviates all the objections incident to structures of similar shape, but having their
parts riveted together.
I have hereinbefore described the invention as applied to a corrugated cylindrical
flue or pipe. but I do not limit myself to such form of pipe, for these improvements
are applicable to plain pipes, and to pipes having other forms in cross section.
.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
First. A headed flue or tube, composed of a cylindrical body, and a flange plate or
head having a circular flanged opening, the flange of the opening being welded to
the end of the cylindrical body, substantially as and for the purpose set forth.
Second. The herein described method of producing headed tubes or flues, consisting
in forming a circular flange around an opening in a plate and welding such flange to
the end of a pipe body, substantially as and for the purpose set forth.
Dated this 5th day of November 1889.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.