In- PROVEMENTS IN APPLYING AND FITTING THE TUBES OF MULTITUBULAR BOILERS, CONDENSERS, AND OTHER LIKE CAPACITIES, AND IN APPARATUS FOR THE SAME
Year: 1867

page_text: LETTERS PATENT to William Clark, of 53. Chancery Lane, in the County
of Middlesex, Engineer and Patent Agent, for the Invention of "In-
PROVEMENTS IN APPLYING AND FITTING THE TUBES OF MULTITUBULAR BOILERS,
CONDENSERS, AND OTHER LIKE CAPACITIES, AND IN APPARATUS FOR THE SAME."
A communication from abroad by Victor Langlois, Chief Naval
Constructor at Cherbourg, and of 29, Boulevart St. Martin, Paris, both
in the Empire of France.
Sealed the 24th September 1867, and dated the 2nd April 1867.
PROVISIONAL SPECIFICATION left by the said William Clark at the
of the Commissioners of Patents, with his Petition, on the
April 1867.
LLLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said Inven-
tions for "IMPROVEMENTS IN APPLYING AND FITTING THE TUBES OF MULTITUBULAR
BOILERS, CONDENSERS, AND OTHER LIKE CAPACITIES, AND IN APPARATUS FOR THE
SAME." to be as follows:---
This Invention relates to improvements in multitubular steam generators
or boilers of marine, locomotive, and other engines. The Invention is also
applicable to tubular condensers or distilling apparatus.
[Price 8d.]

page_text: and in the expense of repairs; 2ndly, it serves as a means of neutralizing the
effects of expansion. The tubes of generators or other apparatus in question
are ordinarily fixed by means of steel or other metal thimbles, which secure
the ends of the tubes in the tube plates. I screw the tubes into the plate at
one end, so that they can be removed at will for the purpose of cleaning; by
this method also the tubes are free to expand without injury to the plates in
which they are fitted.
The Invention further relates to improved apparatus for forming the screw
threads, fitting and removing the tubes.
DESCRIPTION OF SHEETS A.
Figure of the Drawings represents a longitudinal section of a marine
boiler furnace, serving to illustrate the improvements. The, upper tubes are
screwed to the plate according to this Invention. while the lower tubes are
shown as fitted in the ordinary way for the purpose of comparison: Figure 2
shows a front view of this marine boiler: Figures 3 and 4 show a central
vertical section and end view of a tabe secured by a screw attachment to the
plate Figures 5 and 6 show a vertical section and end view of the tube, end
secured by thimble pieces in the ordinary manner, also on a larger scale;
Figure also shows a central vertical section of the ends of a tube secured
by thimble pieces in the ordinary way on a larger scale to Figures and 2.
P. P', are the plates carrying the tubes at each end: C. C. fire and smoke
boxes arranged as in ordinary: A. S. shows the improved mode of fitting the
tubes; S is a collar or enlargement formed or fixed on the tube having a
screw thread, and screwing into a corresponding screwed opening in the
plate P. This opening is made larger than the diameter of the tube to permit
of its being freely removed when it has become furred, the same facilities being
presented for the removal as for the fixing of the tubes. A is the thimble
piece, by means of which the tube is to be secured at the other end, which
permits of any longitudinal expansion by constantly preserving the adjustment
between the tube plates. while the inner and outer bearing surfaces being
cylindrical a perfect joint is obtained by the annular expansion of the tubes.
As before mentioned. U, C'. Figures 5, 6, and 7, show the ordinary mode of
fixing boiler tubes. On the outside of the metal is shown a line indicating

page_text: the thickness of the incrustation, which prevents tubes being removed after
remaining a length of time in the plates in which they are fixed; and in order
to remove the same it is necessary to cut them through at both ends, or more
or less to injure and put them out of shape. The great advantage of removable
tubes will be at once apparent by comparing them with the ordinary plan of
fixing, as in Figures 1, 2, 5, 6, and 7. Removable tubes as described may
be readily removed and refixed, and so prevent the formation of incrustations
by removing at intervals all deposits of such nature; this results at once in a
saving in fuel and a better and more regular production of steam; repairs
to the tubes are reduced to a minimum, while improved access
The application of these improve-
furnace for repairs is also obtained.
ments by facilitating access to the tubes greatly increases the security of
the apparatus, as those in charge can readily ascertain the exact condition
of the boiler tubes at any moment, which cannot be done on the present
system.
to the
Figures 8, 9, 10, 11, 12, 13, 14, and 15 show longitudinal vertical sections
of the ends of boiler tubes provided with screw connections according to this
Invention. The number of turns of the screw threads are varied, as shown,
while the modes of fixing the same to the tube plates are also varied; Figures
16 and 17 show end views of the tubes. The same letters serve for all the
Figures. a, tube; b, screwed end; c, socket projecting from plates d of the
boiler provided with spaces e, by the aid of which the tubes are screwed and
unscrewed. In Figure 8 the projecting socket c is formed with the tube; in
Figure 9 it is formed on the screw end piece and brazed to the tube; in
Figure 10 the projecting socket is formed with a recess to receive the tapered
end of the tube; in Figure 11 the socket c has a similar recess, but with the
tube straight; in Figure 12 the tube is tapered and passes through the socket,
the end being opened outwards to fix it thereto; in Figure 13 the socket is
of similar form, while the tube is straight and secured as before; in Figures
10, 11, 12, and 13 the ends of the tubes and the sockets are brazed together.
In order to prevent oxidation, which would be very prejudicial to the screw
threads, I use a composition formed of suet and zinc, or oxide of zinc in very
fine powder; the screw threads are greased with this composition, which also
facilitates the fixing of the tubes; after the parts have been heated for a few
hours the suet will disappear, while the zinc powder remains on the screw
thread and prevents oxidation. f is a small lead washer encircling a hemp
packing for making a steam-tight joint, the hemp wastes away in course of
time, but the lead remains to form the joint.

page_text: I will now describe the several apparatus for preparing, fixing, and
unfixing the adjustable tubes herein described. These apparatus are repre-
sented in Sheets B of the Drawings; Figure 1 of which shows the key
or spanner, by the aid of which the tubes are fixed in position or removed,
and Figure 2 an end view of the same. a, furnace or fire-box plate;
b, end of the adjustable screwed tube before described; c, socket in the
spaces d, of which is introduced the key e, to be turned by the levers f
and g.
Figure 3 shows a mandril for fitting the tube b to the tube
plate a of the fire-box, it being drawn half the full size; this mandril is
formed of four parts c, c, c, c, mounted on a squared tapered shank d, by
forcing which inwards the end of the tube is caused to adapt itself to
the orifice in the tube plate, after which the thimble piece is forced into
position inside the tube end. Figure 4 shows an end view of this mandril.
Figures 5, 6, and 7 show horizontal sections of the apparatus I employ for
boring and cutting screw threads in the tube plates. Figure 5 is a section
on the line 2, 3, Figure 8. Figure 9, a section on the line 1, 2, Figure 5.
Figure 10 shows the several forms of the screw cutting tools, while Figures
11 and 12 are plans of the tools shown in section at Figures 5, 6, and 7.
The same letters serve for all the Figures 5 to 12, which are shown half the full
size. A, support, fixed in position by a screw and nut a received in one of the
openings of the tube plate b; B, hollow boring tool; C, screw guide bearing
for regulating the screw cutting; this guide first bores a hole in the tube
plate which is to have the screw thread formed in it, for which purpose I
remove the two pins D, when the borer will turn between shoulder P and
collar R, and by means of a key applied at I the tool is operated for drilling
the hole; D, pins serving to fix the screw coupling to the boring tool during
the screw cutting operation; E, ring for maintaining a true central position
of the boring tool; F, hexagonal part of the boring tool, on which is applied
a ratchet wrench for rotating the same; G, steel rod for regulating the hold
of the cutter; H, cutter carrier on the inside of the fire-box; L, cutter for
drilling the hole also from the inside of the fire-box; M, M³, screw cutters;
N, carriers of same; O, cutter for shaping the hole for the tube, also operated
from inside the fire-box.
Figures 13, 14, and 15 show an apparatus for withdrawing the thimble
pieces. Figure 13 is an elevation of a tube end and furnace plate with the
apparatus in elevation; Figure 14 is an end view; and Figure 15 a plan of
same, the same letters apply to these three Figures. a, tube; b, boiler plate;
c, thimble piece; d, swivel head jointed to the shank e of the apparatus,
which after being introduced into tube a bears against the thimble piece c,

page_text: when by traversing the nut g on the screwed end of the stock e said thimble
is forced out of the tube; f. bridge piece; h. spring or catch for holding the
head d in the open position.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the
1st October 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of April, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her
reign, did. for Herself, Her heirs and successors, give and grant unto me, the
said William Clark, Her special licence that I, the said William Clark, my
executors, administrators, and assigns, or such others as I, the said William
Clark, my executors, administrators, and assigns, should at any time agree
with, and no others. from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN APPLYING AND
FITTING THE TUBES OF MULTITUBULAR BOILERS, CONDENSERS, AND OTHER LIKE
CAPACITIES, AND IN APPARATUS FOR THE SAME," a communication to me from
abroad by Victor Langlois, Chief Naval Constructor at Cherbourg, and of
29, Boulevart St. Martin, Paris, both in the Empire of France, upon the
condition (amongst others) that I, the said William Clark, my executors or
administrators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describe and ascertain the nature of
the said Invention, and in what manner the, same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Clark, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the two Sheets of Drawings hereunto annexed,
and to the letters and figures marked thereon (that is to say):-
This Invention relates to improvements in the multitubular steam generators

page_text: or boilers of marine, locomotive, and other engines; the Invention is also
applicable to tube condensers or distilling apparatus.
The improvements consist in providing tubular generators, condensers, or
distilling apparatus with tubes that may be readily fitted in position and
removed when desired. The advantages resulting from such an arrangement
are, 1st, that the tubes may be more readily cleaned. and so effect a saving in
fuel and in the expense of repairs; 2ndly, it serves as a means of neutralizing
the effects of expansion. The tubes of generators or other apparatus in
question are ordinarily fixed by means of a steel or other metal ring which
secures the ends of the tube in tube plates. I screw the tubes into the plate
at one end so that they can be removed at will for the purpose of cleaning;
by this method also the tubes are free to expand without injury to the plates
in which they are fitted.
The Invention further relates to improved apparatus for forming the screw
threads, fitting in position and removing the tubes.
Figure 1, Sheet 1, of the Drawings represents a longitudinal section of a
marine boiler furnace serving to illustrate the improvements.
The upper
tubes are screwed to the plate according to this Invention, while the lower
tubes are shown as mounted in the ordinary way for the purpose of com-
parison. Figure 2 shows a front view of this marine boiler. Figures 3 and 4
show a central vertical section and end view of a tube secured by a screw
attachment to the plate. Figures 5 and 6 show a vertical section and end
view of the tube ends secured by thimble pieces in the ordinary manner, also
on a larger scale. Figure 7 shows a central vertical section of the ends of a
tube secured by thimble pieces in the ordinary way on a larger scale to
Figures 1 and 2. P, P¹, are the plates carrying the tubes at each end; C, C³,
fire and smoke boxes arranged as in ordinary; A, S, shows the improved
mode of fitting the tubes; S is a collar or enlargement formed or fixed on the
tube having a screw thread and screwing into a corresponding screwed opening
in the plate P; this opening is made larger than the diameter of the tube to
permit of its being freely removed when it has become coated with tartar, the
same facilities being presented for the removal as for the fixing of the tubes.
A is a thimble piece, by means of which the tube is to be secured at the other
end, which permits of any longitudinal expansion by constantly preserving
the adjustment between the tube plates, while the two ends being cylindrical
a perfect joint is obtained by the annular expansion of the tubes. As before
mentioned, U, U', Figures 5, 6, and 7, show the ordinary mode of fixing
boiler tubes. On the outside of the metal is shown a line indicating the
thickness of the incrustation, which prevents the tube from being removed by

page_text: the openings in the plates in which the tubes are screwed, and in order to
remove the same it is necessary to cut them through at both ends or more or
less injure and put them out of shape. The great advantage of removable
tubes will be at once apparent by comparing them with the ordinary plan of
fixing, as in Figures 1, 2, 5, 6, and 7. Removable tubes may be readily fixed
or unfixed, and so prevent the formation of incrustations by removing at
intervals all deposits of such nature; this results at once in a saving in fuel,
and a better and more regular production of steam, repairs to the tubes are
reduced to a minimum, while improved access to the furnace for repairs is
also obtained. The application of these improvements by facilitating access
to the tubes greatly increases the security of the apparatus, as those in charge
can readily ascertain the exact condition of the boiler tubes at any moment,
which cannot be done on the present system.
Figures 8, 9, 10, 11, 12, 13, 14, and. 15 show longitudinal vertical sections
of the ends of boiler tubes provided with screw connections according to
this Invention. The number of screw threads are varied, as shown, while
the modes of fixing the same to the tube plates are also varied. Figures 16
and 17 show end views of the tubes. The same letters serve for all these
Figures. a, tube; b. screwed end: c. socket projecting from plate d of the
boiler provided with spaces e by the aid of which the tubes are screwed and
unscrewed. In Figure 8 the projecting socket c is formed with the tube; in
Figure 9 it is formed on the screw end piece and brazed to the tube; in
Figure 10 the projecting socket is formed with a recess to receive the lapered
end of the tube; in Figure 11 the socket has a similar recess, but with the
tube straight in Figure 12 the tube is tapered and passes through the socket.
the end being opened outwards to fix it thereto; in Figure 13 the socket is
of similar form. while the tube is straight and secured as before: in Figures
10. 11. 12, and 13 the ends of the tubes and the sockets are brazed together.
In order to prevent oxidation, which would be very prejudicial to the screw
threads use a composition formed of suet and very fine zine or oxide of
zinc in powder: the screw threads are greased with this composition, which
also facilitates the fixing of the tubes. After the parts have been heated for a
few hours the suet will disappear. while the zinc powder remains on the screw
thread and prevents oxidation. is a small lead washer encircling a hemp
packing for making a tight joint. the hemp soon vanishes. but the lead remains
to form the joint.
I will now describe the several apparatus for preparing, fixing, and unfixing
the adjustable tubes herein-before described.
These apparatus are represented in Sheet 2 of the Drawings, Figure 1 of

page_text: which shows the key or spanner by the aid of which the tubes are fixed in
position or removed; and Figure 2 an end view of the same. a, furnace or
fire-box plate; b, end of the adjustable screwed tube before described; c,
socket, in the spaces d of which is introduced the key e to, be turned by the
levers and g. Figure 3 shows a mandril for fitting the tube b to the tube
plate a of the fire-box, it being drawn half the full size; this mandril is formed
of four parts c, c, c, c, mounted on a square tapered shank d, by forcing which
inwards the end b of the tube is caused to adapt itself to the orifice in the tube
plate, after which the thimble piece is forced into position inside the tube end.
Figure 4 shows an end view of the mandril. Figures 5, 6, and 7 show longi-
tudinal sections of the apparatus 1 employ for boring and cutting screw threads
in the tube plates; Figure 5 is a section on the line 2, 3, Figure 8. Figure 9
a section on the line 1, 2, Figure 5. Figure 10 shows the several forms of the
screw-cutting tools; while Figures 11 and 12 are plans of the tools, shown in
section at Figures 5, 6, and 7. The same letters serve for the Figures 5
to 12, which are shown half the full size.
A, support fixed in position by a screw and nut a received in one of the
openings of the tube plate b; B, hollow boring tool; C, screw coupling for
regulating the screw cutting; this apparatus first bores a hole in the tube
plate which is to have the screw thread formed on it, for which purpose 1
remove the two pins D when the borer will turn between the shoulder P and
collar R, and by means of a key applied at 1 the tool is operated for drilling
the hole; D, pins serving to fix the screw coupling to the boring tool during
the screw-cutting operation; E, ring for maintaining the true central position
of the boring tool; F, hexagonal part of the boring tool on which is applied
a ratchet wrench for rotating the same; G, steel rod for regulating the cutter;
II, cutter carrier on the inside of the fire-box; L, cutter for drilling the hole,
also from the inside of the fire-box; M, M', screw cutters; N, carriers of same;
O, cutter for shaping the hole for the tube, also operated from inside the fire-box.
Figures 13, 14, and 15 show an apparatus for withdrawing the thimble pieces.
Figure 13 is an elevation of a tube end and furnace plate with the apparatus
in elevation; Figure 14 is an end view, and Figure 15 a plan of same. The
same letters apply to these three Figures. a, tube; b, boiler plate; c, thimble
piece; d, swivel head jointed to the shank e of the apparatus, which after
being introduced into tube a bears against the thimble piece c, when by
traversing the nut g on the screwed end of the stock e said thimble is forced
out of the tube: f, bridge piece; h, spring or catch for holding the head d in
the open position.
Having described the nature of this Invention, and the manner of performing

page_text: the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is, - -
First, the improved screw fittings for fixing adjustable tubes of steam gene-
rators or tubular condensers of all kinds in the manner before described, and
as illustrated in the Drawings annexed.
Secondly, I claim the several apparatus for boring and preparing the plates
and fitting and removing the tubes, all as before described.
In witness whereof. I. the said William Clark, have hereunt set my
hand and seal, this Twenty-fifth day of September, in t
Lord One thousand eight hundred and sixty-seven.
of our
W. CLARK. (L.S.)