Improvements in and in Connection with Tubes and Tube Plates of Steam Generators, and in the Mode and Apparatus Employed in the Construction of such Tube Plates.
Year: 1885

page_text: Improvements in and in Connection with Tubes and Tube
Plates of Steam Generators, and in the Mode and Apparatus
Employed in the Construction of such Tube Plates.
I HENRY TURNER, of 6 Barnard Road, Claughton, Birkenhead, in the County
of Chester, Engineer do hereby declare the nature of the said Invention for
IMPROVEMENTS IN AND IN CONNECTION WITH TUBES AND TUBE PLATES OF STEAM
GENERATORS AND IN THE MODE AND APPARATUS EMPLOYED IN THE CONSTRUCTION
OF SUCH TUBE PLATES to be as follows:-
My Invention has for its object certain improvements hereinafter more par-
ticularly described in an in connection with tubes and tube plates and in the mode
and apparatus employed in the construction of such tube plates, and my Invention
is particularly applicable to what are known as high pressure steam generators.
Tubes, tube plates, also apparatus and mode of operation employed in the
construction of the tube plates with my improvements applied thereto consist as
follows:
Holes of lesser diameter than the outside of the tube end are formed, preferably
drilled, or bored in the flame box tube plate. These boles are then expanded by a
mandril to a size large enough to receive the tube ends, which is effected in the
following manner. The tube plate having been drilled with the desired number of
holes of smaller diameter than that of the tube ends and made hot is placed over a
matrix, preferably in the anvil block, of a steam hammer (but any other suitable
power may be utilized for this purpose, such as gas, water, air, or their equivalent).
The lip of this matrix is provided with a recess. A tapered die (of form herein-
after described) which is fitted to the head of the steam hammer is caused to
descend and pass through the hole, which has been placed over the matrix and
presses an annular piece of metal into the recess of the matrix before spoken of.
Thus the tube plate when completed in this manner will be provided with a rim
of projecting metal, round each hole and thereby forming an extra amount of
bearing metal over the ordinary practice to which the tube ends are to be attached.
The projection is of course formed upon the inner, or water side of the tube plate
and the size to which the holes are thus expanded is regulated according to the
size of the tube ends.

page_text: The form of the die is of increasing diameter, towards its upper portion, the
increase taking the nature of a concave curve and the angle of entrance is inore
acute than the angle at the terminus of the die. A further portion of this die is
made parallel or substantially parallel, or having a small taper and again above
this portion is provided a shoulder which forms a stop to the die and rounds the
corner of the hole.
The tubes are provided at their flame box ends with enlarged, or thickened
tapered ends which are provided with an external thread. The flame box tube
plate holes, are provided. with tapered threads to correspond with the screwed tube
ends which are screwed into the threaded holes and thereby secured. A further
means of securing is effected by so arranging the sizes of the tube ends and the
holes, that the tubes project beyond the tube plate, these projecting ends being
turned outwards, or beaded over against the tube plate. The tubes may be further
tightened by expanding..
The smoke box end tube plate holes are made of larger diameter than those in
the flame box tube plate. This provision affords an easy entrance to the screwed
ends of the tubes. The tubes at the smoke box end are swelled to correspond with
the tube plate holes in which they are expanded. In the case of what are known
as stay tubes, I provide the smoke box end of the tubes with a projecting thread
to take internal and external nuts, between which the tube plate comes, but these
ends may also be screwed with parallel screws through the smoke box tube plate
and provided with outside nuts only: The flame box end of these tubes are
formed and fitted in a similar manner to those before described.
By my Invention; I obtain a long lateral bearing to the flame box end of the
tubes, as against the ordinary sprung expanded joint, only; at the same time the
screwed and tapered form thereof allows of the tubes being screwed into their
seats until a perfect joint is made with the tube plate, and further, the ends being
turned up, or beaded over against the tube plate an additional protection against
leakage of water is provided. It will be readily seen from the above.description
that it is practically impossible for any leakage of water into the flame box to take
place; or for the tubes to become loose. Thus each individual tube. may be said to
form a stay tube.
:
To make the tubes tight and bear against their seats at the flame box end, if
any of such tubes should become loose, it only requires a small part of a turn of
the tubes to effect it, and the tubes can be made tight from the smoke box end,
thus obviating the delay which occurs in ordinary boilers when repairing, or
retightening tubes.

page_text: tube plate A when completed in this manner will be provided with a rim a¹ of
projecting metal round each hole & and thereby forming a seat having an extra
amount of bearing metal over the ordinary practice, to which the tube ends are to
be attached. The projection a¹ is shown formed upon the inner, or water side of
the tube plate A, but it may be formed on the flame box side, and the size to
which the holes a are thus expanded is regulated according to the size of the
tube ends.
The form of the die cis of increasing diameter, towards its upper portion, the
increase taking the nature of a concave curve at c¹ and the angle of entrance at c'
is more acute than the angle at the terminus of the die cat c³. A further portion
of this die c is made parallel at c¹, or substantially parallel, or having a small taper
and again above this portion is provided a shoulder c which forms a stop to the
die c'and rounds the corner of the hole a.
The tubes D are provided at their flame box ends & with enlarged, or thickened
tapered ends which are provided with an external screw thread. The holes a of
the flame box tube plate A are then bored to a taper and provided with tapered
threads d² to correspond with the tapered screwed tube ends d¹ which are screwed
into the threaded holes a and thereby secured. A further means of securing is
effected by so arranging the sizes of the tube ends d and the holes a that the
tubes D project beyond the tube plate A, thèse projecting ends being turned out-
wards, or beaded over against the tube plate as at e. The tubes D may be further
tightened by expanding.
The holes f in the smoke box end tube-plate E are made of larger diameter than
those in the flame box tube-plate A. This provision affords an entrance to the
screwed ends d¹ of the tubes D. The tubes D at the smoke box end are swelled
at g to correspond with the tube-plate holes fin which they are expanded in the usual
way. In the case of what are known as stay tubes, I provide the smoke box end
of the tubes D with a projecting thread g¹ to take internal and external nuts h, h³,
between which the tube plate. E comes, but these ends may also be screwed with
parallel screws through the smoke box tube-plate and provided with outside nuts /
only. The flame box end of these stay tubes D are forined and fitted in a similar
manner to those before described.
By my invention I obtain a long lateral bearing to the flame box, end of the
tubes, as against the ordinary expanded joint only, at the same time the screwed
and tapered form thereof allows of the tubes being screwed into their seats until a
perfect joint is made with the tube plate, and further, the ends being turned up, or
beaded over against the tube plate an additional protection against leakage of
water is provided. It will be readily seen from the above description that it is
practically impossible for any leakage of water into the flame box to take place,
or for the tubes to become loose. Thus each individual tube may be said to form
a stay tube.
To make the tubes tight and bear against their seats at the flame box end, if
any of such tubes should become loose, it only requires a small part of a turn of
the tubes to effect it, and the tubes can be made tight from the smoke box end by
a key or spanner which takes into the provisions in the tube ends provided for
that purpose, thus obviating the delay which occurs in ordinary boilers when
repairing or retightening tubes.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
First. The joint or connection of tube and tube plate consisting of a tapered
screwed hole a formed in and by the tube plate and rim and a corresponding
tapered screwed tube end d³, substantially as set forth.
Second. The combination of the tube end d¹ enlarged and having a tapered
thread, with the tube plate A and rim a¹ thereof, substantially as and for the.
purposes set forth.

page_text: Third. Effecting the fitting or jointing of tubes and tube plates by a tapered
serewed tube end and a corresponding tapered screwed tube plate bearing or seat,
inserted and fitted in place substantially in the manner set forth.
Fourth. The combination with a tube and tube plate connection of the type
herein described, of the enlargement g or g¹ of the tube at its opposite end,
substantially as and for the purposes set forth.
Fifth. The mode substantially herein described of constructing the seats for
tubes in tube plates, which mode consists of first providing the plate with holes of
lesser diameter than the tube ends and afterwards enlarging such holes to the
required size and forming a lengthened seat for such tube, substantially as set
forth.
Sixth. The mode particularly herein described with reference to the drawings of
constructing the seats for tubes in tube plates, which mode consists of first drilling
holes a of lesser diameter than the tube ends in the tube plate and afterwards
enlarging such holes to the required size and forming rims a¹ thereon by a die and
matrix such as c and B, operated substantially as set forth.
Seventh. The die c constructed with a tapered portion cl, a parallel or nearly
parallel portion c and a shoulder c³, substantially as set forth with reference to
Figure 3 of the drawings for the purposes described.
Eighth. The matrix B constructed with a lip b and a recess b', substantially as
and for the purposes set forth with reference to Figure 3 of the drawings.
Dated this on
11
CC
1000