Improvements in the Manufacture of Lead Lined or Coated Pipes and Tubes.
Year: 1898

page_text: Date of Application, 9th Apr., 1898-Accepted, 25th June, 1898
[Communicated from abroad by HENRY WALL DAVIS, of Hallein bei Salzburg,
Austria, Paper Manufacturer.]
Improvements in the Manufacture of Lead Lined or Coated Pipes
and Tubes.
I, WILLIAM GEORGE HEYS, of 70, Market Street, Manchester, in the County of
Lancaster, Chartered Patent Agent, do hereby declare the nature of this in-
vention, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
It has long been known that when metallic pipes are exposed to, or are used for
the conveyance of, certain acid liquids fumes and vapours, it is advantageous to
construct them of, or to line or coat them with, metallic lead. But although
this metal resists the corrosive action and protects the pipes to which it is applied
or which are constructed therefrom, its use up to the present time has been
attended with inconveniences, some of which are:-The inability of lead alone
to withstand pressure or to prevent deformation under changes of temperature.
And, in the case of lined or coated pipes, the fact that actual union between the
lead and the metal of the supporting pipe not having hitherto been effectively
obtained, the lead was likely to creep upon the harder metal and eventually to
fissure and crack. These and other inconveniences are overcome by the present
improvements which secure in practice a perfect union between a lead liner or
coating and a supporting copper or other metallic pipe.
In carrying out this invention, the copper brass or other hard metallic support-
ing pipe is thoroughly cleaned and tinned in the usual manner on that surface
with which the lead is to be joined, that is to say on the outer surface for a
coating and on the inner surface for a lining. I then prepare a lead tube to fit
substantially outside the supporting tube for a coating or inside that tube if for
a lining, and this tube also is carefully tinned on that surface which is to come
into contact with the supporting tube. It is to be understood that the lead tube
is to have such dimensions that when tinned it can be drawn into or over the
supporting tube.
The tinned lead tube having been arranged in position, it is forced into close
contact. This may be done in the case of a liner by forcing a mandrel or plug
through the lead tube and in the case of a coating by drawing a die over it. The
two tubes having thus been brought into close physical contact, are subjected
to a temperature which will suffice to melt the tin without melting the lead. This
temperature may conveniently be about 500 deg. F. A convenient method for its
application is by means of an oven provided with a pyrometer and means for
controlling the temperature. Such ovens being already known and commonly
used for annealing and other metallurgical operations, do not require to be
further described. To prevent possible collapse of the linings they may, before
being heated, be filled with sand and to protect the coatings these may be
embedded in sand.

page_text: I am aware that plane and other hard metallic surfaces have already been.
covered with lead by other means and desire therefore that it shall be understood
that I do not make any claim to the protection of such surfaces save as hereinafter
particularly set forth."
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: :―
The herein before described method of lining and coating hard metallic tubes
with lead which consists in tinning the contiguous surfaces of the supporting
tube and of the lead lining or coating, arranging the lining or coating in or
upon the supporting tube, forcing them into intimate contact and subjecting
them to a température sufficient to melt the tin without melting the lead whereby
the two parts are homogeneously connected, substantially as set forth.
W. E. HEYS & SON,
Agents for the Applicant.