A NEW OR IMPROVED BUSH FOR MAKING A PERFECTLY TIGHT JOINT BETWEEN THE BOILER TUBES AND TUBE PLATES OF MARINE, LOCOMOTIVE, AND OTHER STEAM BOILERS
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Henry Morris Walker at the
Office of the Commissioners of Patents, with his Petition, on the
2nd November 1875.-A communication from abroad by Alfred
Estienne, of Marseilles, in the Republic of France.
I, HENRY MORRIS WALKER, of No. 5, Guildford Road, Greenwich,
in the County of Kent, do hereby declare the nature of the said Inven-
tion for "A NEW OR IMPROVED BUSH FOR MAKING A PERFECTLY TIGHT JOINT
BETWEEN THE BOILER TUBES AND TUBE PLATES OF MARINE, LOCOMOTIVE, AND OTHER
STEAM BOILERS," a communication to me from abroad by Alfred Estienne,
of Marseilles, in the Republic of France, to be as follows:-
This Invention has for its object as indicated by the title the making
of a perfectly tight joint between the tubes and tube plates, and in order
that its nature and importance may be distinctly understood it may be
as well to allude to the present system as generally adopted, which
consists in introducing the tubes direct into the tube plates, and fixing
them there in a steam-tight position by means of a tapered bush or
ferrule driven tight into each end of the tube so as to expand that
portion engaged in the tube plate. This means of fixing the tubes in
the tube plate seems at first sight sufficiently good for the purpose, but

page_text: experience proves that it answers the purpose only for a short time.
Steamers adopting this system shewing after one or two short voyages
its evil effects in the shape of leaky tubes, and consequent accumulation
of salt in the vicinity of such leaks, and however small these leaks may
be by themselves they become in the aggregate a serious impediment
to the progress of the ship, impeding as they do the quick generation of
steam, thus delaying the vessel's passage and increasing the consumption
of fuel. In view of these great disadvantages this bush has been
invented intended to connect the tubes and tube plates so perfectly
together as to provent entirely any such leakage occurring to a boiler as
herein-before alluded to.
This improved bush is so constructed and fitted that it has its
narrowed part turned to the exterior diameter of the tubes, and tapered
on the length a little more than the thickness of the tube plate through
which it passes, and is rivetted over the outside of the plate.
The other part of the bush on the inner side of the tube plate is
turned about the same length, but a larger diameter forming a shoulder
to the bush which fits close up to the tube plate, and on the inner or
thick end of the bush a groove is cut of such a size as to receive the end
of the tube, the groove (more or less deep) is rounded in the bottom
which is an important arrangement as it allows a perfect joint to be
made with the tube, and furthermore prevents when the tubes aro fitted
tight between the tube plates any tendency on the part of the stay tubes
to cause the ordinary tubes to bend in their length.
This arrangement of fitting tubes in boilers is as simple as the
ordinary plan. It is sufficient to fix a bush in the manner described in
each hole of the back tube plate by means of a packing of white lead,
india-rubber, or other suitable material, which is placed in the circular
groove of the bush, and the end of the tube inserted therein; when the
tube is in this position a second bush grooved on the innor end similar
to the first is screwed through the front tube plate, and receiving the
other end of the tube in its groove is screwed up until the tube becomes
perfectly tight at both ends, and with the advantage of protecting the
tube ends from exposure or damage.