Improvements in Steam Boiler Tubes and Tube Plates.
Year: 1890

page_text: Date of Application, 18th July, 1890-Accepted, 23rd Aug., 1890
COMPLETE SPECIFICATION.
Improvements in Steam Boiler Tubes and Tube Plates.
I, THOS. WOODMAN, of 4 Worple Road, Wimbledon in the County of Surrey
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 to improvements in steam boiler tubes, and tube plates, and
consists of imparting a novel form to one end of boiler tubes and to construct a tube
plate of corresponding form wherein the said tubes may readily fit, & be thoroughly
steam and water tight to prevent leakage at the joint. In boiler tubes such as hitherto
constructed, leakage has been found an insuperable difficulty and although various
means have been devised from time to time to remedy this defect, no practical result
has yet been obtained.
And in order that my invention may be more fully understood I have shown the
same in the accompanying drawings, in which Fig. 1, is a side view of a boiler tube
fitted to the tube plate, Fig. 2 being a longitudinal sectional thereof. Fig. 3, is a
vertical section of a portion of the tube plate showing one of the recesses in which the
flanged end of the boiler tube is fitted. Fig. 4 is a horizontal section of the end of
the boiler tube detached from the plate. Fig. 5, is a horizontal section illustrating a
modification. Fig. 6, shows the arrangement of the collar g at one end of the boiler
tube. a represents one of my improved boiler tubes which is provided in proximity
to its front end with a flange or enlarged portion & hollowed out or recessed at c.
front tube plate P into which this end of the tube is fixed is likewise formed with a
circular recess d, into which the aforesaid flange b tightly fits as shown in Fig. 2, so as
to form a hermetic joint. n is a nut screwed onto the end of the tube and serves to
fix the latter tightly in position in high pressure boilers, but for low pressure boilers
this nut may be dispensed with, the arrangement shown in Fig. 5, being substituted
therefor.
The
The flange b must be made slightly smaller in diameter than the hole in the rear
tube plate e so as to pass the tube through such hole for axing purposes, while the
other end of the tube should be enlarged as at f to enable it to be secured in the
ordinary manner in such tube plate.
In some cases I prefer not to enlarge the rear end of the tube sufficiently for the
latter to fix in the perforation of the tube plate, but to make up the deficiency or
space by means of a tapered collar g the peripheral edge of which abuts against the
inner rim of the said tube plate e, so as to tightly lock the tube therein.
In the modification shown in Fig. 5. instead of using the tightening nut d, as
above stated, I may use a ferrule h, which is fixed in the ordinary manner.
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. In steam boilers providing one end of a boiler tube with a flange and a recess
fitting in a corresponding part of the front tube plate to prevent leakage at the joint,
substantially as and for the purpose described.
2. In steam boilers providing one end of a boiler tube with a flange and a recess
fitting in a corresponding part of the front tube plate, and furnishing the other end
with a tapered collar fitting tightly in the perforation of the rear tube plate substantially
as and for the purpose described.
3. In high pressure boilers providing one end of a boiler tube with a flange, and a
recess fitted in corresponding part of the front tube plate, and securing the front end

page_text: of the boiler tube by a nut abuting against the said tube plate substantially as and for
the purpose described and shown.
4. In low pressure steam boilers, the combination of a ferrul with the tube and tube
plate claimed above, substantially as and form the purpose described.
Dated this 18th day of July 1890
HUGHES, SON & Co.,
38, Chancery Lane, W.C., Agents.