Method of Fixing Tubes in the Tube Plates of Steam Boilers, and Apparatus for Preparing the Tube Plates, for Expanding the Tubes Therein, and for Extracting the Worn Tubes Therefrom.
Year: 1891

page_text: Date of Application, 29th Oct., 1891-Accepted, 18th June, 1892
COMPLETE SPECIFICATION.
Method of Fixing Tubes in the Tube Plates of Steam Boilers, and
Apparatus for Preparing the Tube Plates, for Expanding the
Tubes Therein, and for Extracting the Worn Tubes Therefrom.
I, ERNEST PETERSEN, of Kertch, Crimea, Russia, 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 :-
My invention relates mainly to an improved method of securing tubes in the tube
plates of boilers, whereby these are fixed so securely and strongly that, leakage
cannot occur under sudden expansions and contraction as at present, and that special
stay tubes with screwed ends such as are now generally employed, are rendered
unnecessary, the fire tubes being themselves made to act effectually as stay tubes.
For this purpose I, in the first instance, form in the circumference of the hole of
the tube plate A, a rounded hollow a Fig. 1 of the accompanying drawings, and I
at the same time round off the outer and inner edges a' a² of the hole, as shewn, and
I then expand the tube B firstly with a bulge 6 fitting the hollow a, secondly with
a bulge b, fitting the rounded edge a¹, and thirdly with the expanded outer end 6*
fitting over the rounded outer edge a².
With this arrangement it will be seen that if owing to the heating of the boiler
the fire tubes are expanded in length while the tube plate is from any cause
prevented from following such expansion, then the shoulder of the bulge b' will
press against the rounded edge a', and the outer half of the bulge 6 will press
against the corresponding part of the hollow a, so as to maintain a watertight joint.
If on the other hand the tube B should shrink in length owing to the sudden
introduction of cold air, then the inner half of the bulge will press against the
corresponding part of the hollow a, and the curved edge 6* will press against the
rounded edge a, thus also forming a tight joint.
At the same time the close fit of a and b, a¹ and b¹, and a² and b³ will form as
strong a joint between the tube and the plate as any joint between a screwed stay
tube and the plate, while avoiding the tendency of the latter to become leaky
through repeated expansion and contraction.
The tube holes of the boiler plate, whether of old or new boilers may be readily
prepared in the above described manner by means of the cutting tool shown at
Figs. 2 to 7 of the drawings, in which Figs. 2, 3, 4 and 5 shew respectively a side
view, a longitudinal section and two end views of a tool to be operated by hand,
more particularly applicable for preparing the tube holes of existing boilers for
receiving the improved tube joint, while Figs. 6 and 7 shew respectively a longi-
tudinal section and an end view of the same tool adapted to be worked in the same
boring machine that serves to cut the tube holes in the plates of new boilers.
The instrument consists of a steel casting C, formed firstly with a cylindrical slotted
part cat one end adapted to fit accurately into the holes of the plate A, but to be
capable of turning freely therein, secondly with a hexagonal or other shaped head c
at the other end for receiving a spanner or double ended wrench for turning it round,
thirdly with central hollow for receiving a conical plug D and its screwed stem D',
fourthly with two slots c³ ³ to receive two steel cutters E which can slide freely in the
same. The plug D has attached to it a cap F the coned sides of which are formed
with the same conicity as the plug and which fit into correspondingly inclined slots e
in the cutters E. The screwed stem D¹ passes up through the central hollow c² of
the casting and has fitted thereon a nut G which is introduced through the lateral
gap c, and by turning which, the plug D can be either advanced between or with-
drawn from the correspondingly inclined inner ends of the cutters E the plugs
being prevented from turning by a stud d on it entering a groove c³ in the hollow.

page_text: From this construction it will be seen that, for commencing the cutting operation
the conical plug D is withdrawn into the position shown at Fig. 6, whereby the
conical cap F will be made to draw the cutters inward by means of its inner sloping
surface till their cutting edges are flush with the periphery of the cylindrical part c,
whereupon the tool can be inserted into the hole as shewn at Figs. 2 and 6. Upon
then turning the nut G, so as to advance the plug, the edge of the cutters, which
are made of a configuration to correspond with the form described with reference to
Fig. 1, are made to bite into the sides of the hole of A, so that on then rotating the
tool by a wrench, the cutters are made gradually to cut the sides of the hole into the
described form, the cuttings being allowed to fall out through the grooves c* in
front of the cutting edges.
In order to determine the exact extent to which the cutters have to be protruded
by the cone D to produce the required configuration stops E¹ E¹ are secured by
screws on each side of the casting, against which the upper ends of the cutters
butt, when protruded to the required extent, these stops being temporarily removed
when it is desired to introduce or replace the cutters, these being inserted into their
slots in c from the outside.
The cutting having been completed, the plug D is withdrawn again by turning
the nut G until the edges of the cutters are flush with the part c, so as to allow of
the removal of the tool.
In the arrangement at Fig. 6 the part C slides through the socket W of a suitable
machine similar to an ordinary vertical boring machine, and is rotated by gearing,
the stem D' being operated either by screw gear or by a lever or cam, for advancing
and withdrawing the plug.
The tube hole having been prepared as above described, and a tube B having
been inserted into it this is then expanded so as to fit the curves a, a', a³, by means
of an expanding tool such as is shown at Figs. 8 to 13 of the drawings. The
essential feature of this expanding tool consists in acting upon the coned ends of a
set of expanding rollers by means of two opposite cones which are simultaneously
advanced, so as to force the two ends of the rollers out in a parallel direction, and
thus expand the end of the tube uniformly at all parts, instead of forcing the
expanding rollers outwards by a single coned mandril driven in between them as
heretofore, whereby firstly the expansion is effected in a very unequal and imperfect
manner and secondly whereby it would not be practicable to expand the tube by
bulging it into hollows as described.
Fig. 8 shows a side view of the improved tube expander, Fig. 9 an end view
thereof, and Fig. 10 shows a longitudinal section on line X X Fig. 9; Figs. 11, 12
and 13 show longitudinal sections in which the expanding rollers have variously
modified forms. The expander consists firstly of a frame formed of two rings H H
connected together by three pillars H', rivetted or screwed thereto.
The rings have three notches h h h on their inner circumference into which fit
the trunnions of the expanding rollers I.
These rollers are formed with their two ends coned as shewn, while the
middle part is formed with circular corrugations ii, of which i serves to form the
middle bulge 6 of the tube Fig. 1, while forms the bulge b' and partially forms
the outward bent edge 62. Centrally between these rollers are situated the
cones J K of which J is formed as a conical head on a stem the part J' of which is
of rectangular or hexagonal cross section with the corners chamfered off as indicated
at Fig. 9 while the end J' is cylindrical and formed with a screw thread, on which
is screwed a nut L. The cone K fits with a hole of a sectional form corresponding
to the stem J', on to the latter, and has a square or polygonal head K' for the
reception of a spanner or wrench for rotating the tool. If desired the extreme
end J' of the stem J₁ J' can be made square or polygonal for receiving a spanner
for rotating the tool.
The cones J K being made with a taper to fit accurately against the coned
parts of the rollers it will be seen that if, after inserting the tool into the tube B
to be expanded into the hole of the plate A, the nut be tightened up against the

page_text: end of the cone K, it will simultaneously force both the cones inwards to the same
extent, thereby forcing the rollers I slightly outwards in a perfectly parallel manner,
and on then rotating the tool, by means of a spanner placed on the square head K',
the corrugations of the rollers will gradually expand the tube so as to form the
bulges band the turned over edge, as shewn at Fig. 10, the slots h of the
rings H being made of sufficient depth to allow of the requisite outward motion of
the roller trunnions. The tube having been expanded as described, the nut L is
screwed back so as to enable the cones to be moved outward sufficiently to allow
the rollers to move inwards again, whereupon the expanding tool can be withdrawn
from the tube.
In order to complete the bending over of the outer edge of the tube, the rollers I
require to be removed from the tool and be replaced by others formed as shewn
at 1 Fig. 11, in which the diameter of the outer bead is increased to the required
extent for the above purpose. This is readily done by screwing off the nut L and
withdrawing the cones J K from the frame, whereupon the rollers I can be readily
removed and replaced by the rollers 1¹.
These rollers are made with the outer part carrying the bead or flange i
separate from the inner part, as shewn, the one part fitting with a cylindrical plug
into a corresponding recess in the other.
On introducing the tube with these rollers into the tube and expanding these so
that the beads i fit into the previously formed bulges of the tube the outer part i
will be drawn partly away from the inner part, with its bead or flange resting
on the partly bent over edge 6 of the tube B, as indicated in dotted lines at
Fig. 11.
On now screwing up the nut L the cone J will not be able to move longitudinally
as the inner parts of the rollers I cannot move outward nor can the tool itself
shift longitudinally in the outward direction on account of the beads i i¹ being held
in the bulges bb, consequently the screwing up of the nut will have the effect of
forcing the cone K inwards and as it can only do this by also forcing the part i
of the roller inwards, towards the other part i¹it will thereby cause the flanges of
the rollers to bend down the edge 6 of the tube while the tool is rotated, until such
edge is bent closely over the rounded outer edge a³ of the tube plate, as shewn in
full lines. The nut L is then unscrewed so as to allow the rollers I' to be retracted
and the tool withdrawn.
It will be evident that the above described tool may be used with rollers of
various configurations, for expanding tubes in various ways, thus the inner bead i¹
may be omitted, so that the tube is only expanded with the bulge b, and bent over
outer end 62, or the middle bead i, may be omitted, so that the tube is held by the
inner bulge b', and the turned over end 62, as at Fig. 12; or again, the rollers may
be made with plain cylindrical middle parts, so as to simply expand the tube into
an ordinary cylindrical hole in the tube plate, as at Fig. 13. In this case the
advantage is gained as already stated, that the tube is expanded in a perfectly
uniform parallel manner against the cylindrical hole of the tube plate, thus ensuring
an accurate fit over the whole of the surfaces in contact, whereas with the ordinary
expanders, a close fit is only insured at the outer edge of the tube plate, on account
of the inclined position which the rollers are made to assume by the conicity of the
mandril.
With tubes expanded into hollows in the tube plate according to my present
invention, the difficulty of removing defective tubes by the ordinary means is
necessarily increased, as the tube ends require to be reduced in size sufficiently to draw
the bulges thereof quite clear of the surface of the tube in the tube plate in order to
allow the tube to be withdrawn and consequently in order to render the described
method of fixing tubes practically applicable it became necessary to devise special
means for withdrawing them.
For this purpose, I have invented the tube contracting tool which is shewn at
Figs. 14 to 17 of the drawings and in certain modified forms at Figs. 18 to 20.
The tool consists mainly of three claws which are made to embrace the turned

page_text: over edge of the tube by means of small rollers, which claws, while they are rotated
round the edge of the tubes are gradually drawn inwards by a screw action and
thus effect the contraction of the tube.
For this purpose, according to the arrangement shewn in clevation at Fig. 14, in
opposite end views at Figs. 15 and 16 and in longitudinal section on line Y Y at
Fig. 17, the three claws M M M, having at their lower ends small rollers N N N
which bear against the edge of the tube to be contracted fit with flat heads M' into
a circular plate which has both a circular groove O' and slots O' to receive
them, the parts M¹ being made of reduced width as shewn at Figs. 14 and 16, so
that shoulders are formed which bear against the underside of the plate O. The
heads M are kept within the slots and groove of the plate by light springs P, and
the parts of the groove O¹ between the several heads are filled in with segmental
pieces O³ secured by rivets as shewn, so that the sides of the heads M¹ fit close
against these pieces while they are free to slide radially in and out to a slight
extent.
The plate has a central boss O' formed hexagonal for the reception of a
wrench or spanner. Centrally through the plate passes a spindle S on which are
formed at Sand S' respectively right and left handed screw threads on the
thread S¹ is screwed a disc Q having rollers R formed to fit the inner curvature of
the claws and having a circular rib fitting into a longitudinal groove in the claw.
On the thread S* is screwed a disc Q' having openings corresponding in shape to
the claws M, through which these pass, as indicated in Figs. 15 and 17, and, having
rollers R' which bear against the outer surface of the claws and are made with a
concave curvature to fit such surface, these roilers being held in position in the
recesses of the disc by plates V secured by screws. The disc Q has three or more
handles Q fixed or formed thereon.
On the square upper end of the spindle S is secured a socket S³ with hexagonal
head S of the same size as the head 04, so as to fit the same wrench or spanner.
In the threaded hole of the socket S3 is screwed a screw bolt T with pointed head
which is made to bear against a suitable abutment temporarily placed against the
back wall of the boiler, or afforded by a special support to be presently described
in order to keep the contracting tool in position against the tube plate. The parts
being in the position shewn at Fig. 17, with the discs Q and Q' situated close
together, while the lower ends of the claws M are expanded so as to fit with their
rollers N against the edge of the boiler tube to be contracted, it will be seen that
on turning the screw spindle S by a spanner fitted on S* so as to cause the
discs QQ to move away from each other the rollers R of Q, in pressing against
the inner surfaces of the upper parts of the claws, will cause these to move outwards
somewhat, while at the same time the rollers R¹ of Q' in pressing against the outer
inclined surfaces of the lower parts of the claws will cause these to move inwards,
and consequently by the combined action of the two discs, a strong compressing
action will be exercised by the claws upon the edge of the tube, so that if the claws
be now rotated by shifting the spanner from S on to O' the rollers N in rolling
round the edge of the tube, will exert their pressure upon the whole of the circum-
ference and will thereby effect the partial contraction thereof. By thus alternately
turning the screw spindle so as to move the jaws inwards and then rotating the
jaws, the tube will be gradually contracted to the required extent. The rotation
of the tool can be assisted by the handles Q2 on the disc Q', and these also serve
to prevent the tool from rotating when the spindle S is being turned. When the
tube has been sufficiently contracted, the discs Q and Q are brought back to their
original position at Fig. 17 by turning spindle S in the contrary direction so as to
allow the claws to expand again. The rollers N are held in position in their
recesses in the claws, by being formed with circular grooves as shewn, into which
take pins N passed through the metal of the claw.
I
Fig. 18 shews a vertical section and Fig. 19 a plan of a modification of the above
described contracting tool. In this case the disc O with groove O' into which the
bent ends M¹ of the claws M fit, is formed with a screwed stem 0%. The groove O¹

page_text: 18 made to fit the bend of the claws accurately at its outer edge, while the inner
part is undercut, whereby the claw pieces are free to turn on the edge of the disc
through a small angle as on a hinge. On each side of the claw a pin P¹ is screwed
through the disc O, so as to prevent any shifting of the claw in the groove.
Embracing the three claws is a ring Q3 bearing with rollers R³ upon the claws,
and connected by arms Q to an upper ring Qwhich can slide on the screwed
stem 05.
A nut S is screwed on to the stem 0° so as to bear upon the ring Q' and the
outer end of the stem is formed square or polygonal to receive a spanner or
wrench by means of which the stem, and with it the entire tool can be turned
round.
Thus in this case the pressing inwards of the claws M is effected by forcing the
ring Q³ down over them by screwing down the nut S against the ring Q and the
rotation of the tool is effected by turning the spindle O' with a spanner. The
claws M are expanded again by light springs X after the withdrawal of the ring Q³;
such withdrawal may either be effected by hand on screwing back the nut S' or a
nut U may be provided on the stem O which is turned by a spanner so as to bear
against the inner face of the ring Q' for forcing Q³ back."
Fig. 20 shews a longitudinal section of a modification of the first described
construction in which the claws M are formed in one with the part O 05, being
made to spring sufficiently at the shoulders M, to allow of their being forced
inwards by the ring Q
Should it be found that the tubes B are of such strength as to require
considerable power to contract them to the required extent by the above described
tool, the tube B may previously have a circular groove cut in it as indicated in
dotted lines at Fig. 17, which might be readily effected by providing suitably
shaped cutters in a tool similar to that described with reference to Figs. 2 to 5 of
the drawings, the cylindrical boss c being of course made of a size to fit into the
interior of the tube B.
When expanding the ends of the tubes over the rounded outer edge of the tube
plate, as described with reference to Fig. 11, and also when using the contracting
tool on the front side of the boiler in positions where there is no opposite point of
support it is necessary to provide a special supporting appliance which is shewn
respectively in longitudinal section, end view, and cross section at Z Z at Figs. 21,
22 and 23 of the drawings, which is made adjustable so that it can be used either
with the expanding tool or with the contracting tool. It consists of a tubular
pillar k having a base which is formed of a semi-circular part k', formed in one
with k and two separate segmental parts the three forming together a cylinder
which fits into the end of the fire tube B. These parts have a conical hollow k³,
into which fits the conical head of a screw bolt passing through the base and
having a nut 1, so that by screwing up this nut, the parts kk are expanded so as
to fit the tube tightly and thus hold the tubular pillar securely in position.
Intok fits accurately a cylindrical stem m having however freedom to slide and
turn therein, and formed in one with the stem is an arm m¹ having a dovetail
slot m³, as shewn at Fig. 23 in which slides a block n. The stem m has a bolt o
passing through it having a coned head o¹ fitting the coned hole in the end of m
which is made with two or more longitudinal slits as shewn, so that by screwing up
the nut p, the end of the stem m will be expanded by o so as to fit tightly against
the interior of k, and thus hold m securely in whatever position it may have been
adjusted to.
For holding the tube expander Fig. 8 in position, a screwed spindle q is screwed
through the block n so as to bear with its point against the end of the stem J³ and
thus afford the requisite pressure for fully expanding the end of the tube B as
described with reference to Fig. 11.
For holding the tube contractor Fig. 14 in position, the stem m is slid out of k to
the required distance, and secured as described, and a solid block n is fitted in the
arm m against which bears the point of the screw T of the contractor.

page_text: tool in the two tubes B adjacent to that in which the column k is fixed, and by
turning the stem m round in k, it will act as support for all the tubes situated
within a circle of which m' is the radius.
The separate parts kkk of the base are held together by a ring r fitted in a
groove therein.
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 :-
1. The method of securing tubes in the tube plates of boilers, consisting in first
cutting a circular groove (a) in the circumference of the hole for the tube, and rounding
off the inner and outer edges thereof (a' a²) and then expanding the tube firstly
with a bulge (6) fitting into the annular groove, secondly with another bulge (6)
bearing against the inner rounded edge of the plate, and thirdly with a turned over
outer edge (2) fitting against the outer rounded edge of the plate.
2. Apparatus for preparing the tube plates in the manner referred in the
preceding claim consisting of a cylindrical body (C) fitting the tube hole of the
plate, in which body are two or more radially sliding cutters (E) that, after insertion
of the body into the hole, are made to project radially by a conical plug (D) forced
forward by a screw, so that on rotating the body the cutters are made to cut the
circular groove and at the same time round off the inner and outer edges, while on
screwing the plug backward again, a conical cap (F) in entering incliued slots in
the cutters draw these inwards again so as to allow the tool to be removed
substantially as described.
3. Apparatus for expanding the tubes in the holes of the tube plate according to
the method set forth in Claim 1, consisting of a set of rollers (1) having circular
beads corresponding to the hollow and rounded edges of the tube plate, and having
two conical ends, which rollers are carried in slots in a frame so as to be readily
removeable, and are acted upon by two opposite cones (J K) arranged on a screwed
stem so that by making the cones approach each other, they force the rollers out-
wards, and thereby cause them to bulge the tube into the recess and over the
rounded edges of the tube plate, substantially as described.
4. In apparatus for expanding tubes referred to in Claim 3, constructing the
expanding rollers of two separate parts so that for finally expanding the outer edge
of the tube, the outer part of the roller provided with a correspondingly formed
flange is forced down over the edge of the tube by the approach of the two cones,
substantially as described.
5. In apparatus for expanding tubes referred to in Claim 3 constructing the
expanding rollers with variously formed peripheries for expanding the tubes with
bulges of any form, or with a plain cylindrical surface, substantially as described.
6. Apparatus for contracting tubes so as to enable them to be removed from the
hole in which they have been expanded without using hammer and chisel as is
usual, consisting of three or more claws (M) having rollers (N) at their one end
which are made to press against the edge of the expanded tube while their other
ends are guided in a grooved disc (0) through which passes a spindle (S) having
right and left handed screw threads, the one thread being made to screw through a
disc (Q) having rollers (R) that bear against the inner surface of the claws (M)
while the other screw thread screws through a disc (Q¹) having rollers (R¹) that
bear against the outer surface of the claws (M) so that by turning the screw spindle
so as to move the two discs away from each other, these are made to force the ends
of the claws that bear against the edge of the tube inwards so as to effect the con-
traction of the same by the rotation of the tool, substantially as described with
reference to Figs. 14, 15, 16 and 17.
7. The modified form of the tube contractor referred to in Claim 6, wherein the
disc acting on the inner sides of the claws is dispensed with, the contraction of
the claws being effected by an external ring (Q³) that is forced down over them by

page_text: means of a screw nut (S) upon a screwed stem (0%) formed on or fixed to the
grooved disc (O) that holds the other ends of the claws, the said nut being made to
act on a ring (Q) sliding on the screwed stem and connected to the first named
ring by suitable arms (Q) substantially as described with reference to Figs. 18, 19,
and 20.
8. A support for holding the tools referred to in the preceding claims in position,
consisting of a tubular column (k) secured in a fire tube by an expanding
base (k) and containing a sliding stem (m) with projecting slotted arm (m²)
containing an adjustable block (n) the stem (m) being secured in the required
position in the column (k) by a conical headed bolt (o) expanding the split end of
the stem, substantially as described with reference to Figs. 21 22 and 23.
Dated this 29th day of October 1891.
ABEL & IMRAY,
Agents for Applicant.