Improvements in and Apparatus for Piokling and Polishing the Internal Surfaces of Metal Tubes.
Year: 1889

page_text: Date of Application, 27th June, 1889
Complete Specification Left, 27th Mar., 1890-Accepted, 7th June, 1890
PROVISIONAL SPECIFICATION.
Improvements in and Apparatus for Piokling and Polishing the
Internal Surfaces of Metal Tubes.
1
I, JAMES YATE JOHNSON, of 47 Lincoln's Inn Fields, in the County of Middlesex,
Gentleman, do hereby declare the nature of this invention, which has been com-
municated to me from abroad by Jean Pierre Serve of rue des Servettes, Givors,
Rhone, in the Republic of France, Manufacturer, to be as follows:-
This Invention relates to an improved process and apparatus for pickling and
polishing the internal surface of metal tubes of all descriptions employed in the con-
struction of steam generators condensers and for other purposes and has for its object
obtaining certain important advantages which I will briefly mention before proceeding
to describe the Invention.
The Invention economises the acid employed in pickling as it enables the operations
of pickling and polishing to be confined to the interior of the tubes the methods
heretofore employed necessitating pickling the outer surface as well as the inner
surface and a corresponding expenditure of acid.
Moreover by means of this Invention the thin layer of metallic oxide on the outer
surface of the tube is enabled to be preserved and this oxide under the special
conditions in which it is generally produced greatly contributes to the preservation of
the tubes.
The economical and practical methods of manufacture hereinafter described also
tend to enable internally polished tubes with or without internal ribs or projections to
be brought into general use these tubes presenting important advantages in a great
number of the purposes to which they can be applied.
Pickling the tubes-In order to perform the pickling process according to this
Invention a trough lined with lead is arranged at a suitable depth below the surface of
the ground or floor of the place where the operation is performed and this trough is
provided near its upper part with a transverse bar or shelf covered with a thick pad
of india rubber. The depth at which this shelf is placed below the floor is regulated
according to the length of the tubes so that their upper part may be conveniently
within reach of the workmen standing on the working floor or platform.
One end of the tube is prepared by carefully cutting it square and even so that
when placed vertically with this end resting on the rubber pad on the shelf herein-
before described the weight of the tube is sufficient to make a tight joint between the
bottom end of the tube and the rubber. At a suitable elevation above the tubes there
is a second trough similar to the first or a cistern provided with a series of cocks or
rubber tubes with spring clamps corresponding with the series of tubes placed
vertically beneath them as herein before explained.
Under these conditions the tubes can be readily filled with diluted acid and allowed
to remain with their internal surfaces only exposed to the action of the acid for the
time necessary for the pickling. When this operation is concluded the tubes simply
require to be displaced or slightly inclined in order to allow the liquid to run out
into the lower trough whence it can be drawn off by pumps or other suitable means.
If necessary the external surface of the tubes may be coated with grease or other
protecting material in order to preserve it from the action of any splashes or drops of
acid that might fall on it in the course of the operation.
Polishing the tubes-The tubes after pickling as herein before described may be
polished in the ordinary way by means of leathers or other suitable appliances acting
with the addition of pulverized grit, emery powder pumice stone or the like
but the operation is more quickly and economically performed by proceeding as
hereinafter described.

page_text: According to this Invention the polishing is effected by introducing in the tube,
which has been previously pickled and is firmly supported throughout its entire length
a mandril made to fit the interior of the tube and of such diameter as to enable it to
exert a sufficiently powerful pressure to rapidly polish the internal surface of the tube
by friction..
It will be understood that under these conditions it is important for the tube to be
very strongly compressed over its entire outer surface so as to prevent it from giving
way under the strain of the pressure exerted by the mandril as it is drawn through the
tube.
With this object the pickled tube is placed in a supporting case formed by a species
of mould made very strong and rigid being composed of two semicylindrical sections
having their internal surfaces accurately shaped in such a manner that when the mould
is closed its internal diameter is somewhat less than that of the tube to be placed
therein. One of the parts or sections of the mould is fixed preferably in a horizontal
position, the other part is moveable and is maintained in contact with the lower part
by means of one or more hydraulic presses or other equivalent means.
The external diameter of the tube placed in the mould being slightly greater than
the internal diameter of the mould, the pressure exerted by the presses connected to
the mould is distributed over the whole of the external surface of the tube which is
thus very powerfully compressed throughout its length.
This compression has the effect in the first place of truly straightening the tube and
taking out any curvature or irregularity that may result from the manufacture and in
the second place of rendering it absolutely impossible for the tube to give way or burst
under the internal pressure of the mandril.
In order to maintain the parts of the mould securely in their proper relative
positions these parts are provided with guides or projections and recesses carefully
fitted so as to steady them during the operation and a small shoulder is formed in the
mould near one end to form a bearing for the end of the tube and prevent it from
becoming displaced longitudinally without interfering with the movement or passage
of the polishing mandril.
The said mandril usually made of tempered steel and polished is of a form exactly
corresponding with the internal shape of the tube and is slightly larger than the
internal space in the tube. This mandril is attached to the extremity of a strong
metal rod whose length exceeds that of the tube and which is actuated by the piston
of a hydraulic press or the clamps of a draw bench or the like.
It will be readily understood that under these conditions the metal of the tubo,
being powerfully compressed between the circumference of the mandril and the
interior of the mould cannot be injured, but the unevenness or roughness of its internal
surface is smoothed out and disappears under the action of the mandril, the pores of
the metal being slightly compressed although the tube is elongated to an inconsiderable
extent only. After this polishing process the mould is opened by raising the hydraulic
presses and the finished tube can then be removed.
The form arrangement and details of construction of the apparatus hereinbefore
described may be modified in various ways. For example the two parts of the mould
may be connected together by any suitable mechanical means such as hoops wedges
keys screws and the like and the moveable part of the mould may be jointed to the
stationary part by means of hinges or it may be made entirely independent or
removable from the said fixed part if preferred.
In place of employing a fixed or stationary mould or support for the pipes the
support may be rendered moveable by placing it on a carriage or on slides and
arranging it to bear against stops provided for the purpose in order to resist the
tractive strain exerted on it longitudinally by the action of the mandril.
According to another arrangement the mandril may be stationary one end of the
stem or rod to which it is attached being secured to stationary supports and the
moving power being applied to the support or case carrying the tube which is thus
drawn over the mandril in place of drawing the mandril through the tube the result
being the same in both cases.
1

page_text: This process for rapidly polishing all descriptions of tubes can be employed with
equal advantage for polishing tubes prepared by the pickling process hereinbefore
described or by any other ordinary or suitable pickling process whether the tube be
pickled or polished on its outer surface or not the essential feature of the Invention
consisting in supporting the tube externally throughout its length in order to prevent
any accidental distortion or injury to the tube and to polish the internal surface by
the great pressure and friction of the mandril as herein before described.
D 11711 of June 1880
COMPLETE SPECIFICATION.
Improvements in and Apparatus for Pickling and Polishing the
Internal Surfaces of Metal Tubes.
I, JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this Invention (which has been communi-
cated to me from abroad by Jean Pierre Serve of rue des Servettes, Givors, Rhone in
the Republic of France Manufacturer) and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:-
This Invention relates to an improved process and apparatus for pickling and
polishing the internal surfaces of metal tubes of all descriptions. employed in the con-
struction of steam generators, condensers and for other purposes and has for its object
obtaining certain important advantages hereinafter set forth.
The use of this Invention effects economy in the acid employed in pickling as it
enables the operations of pickling and polishing to be confined to the interior of the
tubes, the methods heretofore employed necessitating pickling the outer surface as
well as the inner surface and a corresponding expenditure of acid.
Moreover by means of this Invention the thin layer of metallic oxide on the outer
surface of the tube can be preserved and this. oxide under the special conditions in
which it is generally produced greatly contributes to the preservation of the
tubes.
Internally polished tubes with or without internal ribs or projections present
important advantages in the construction of apparatus employed in certain manu-
factures and this Invention enables the demand for these tubes to be more readily
supplied than is possible with the processes of manufacture heretofore employed.
Pickling the tubes-In order to perform the pickling process according to this
Invention a trough or vessel lined with lead is arranged at a suitable depth below the
surface of the ground or floor of the place where the operation is perforined and this
trough is provided near its upper part with a support such as a transverse bar or shelf
covered with a thick pad of india rubber. The depth at which this shelf or support is
placed below the floor is regulated according to the length of the tubes which are
placed vertically thereon so that their upper part may be conveniently within reach of
the workman standing on the working floor or platform.
One end of the tube is prepared by carefully cutting it square and even so that
when placed vertically with this end resting on the rubber pad the weight of the tube
is sufficient to make a tight joint between the bottom end of the tube and the rubber.
At a suitable elevation above the tubes there is a second trough or cistern similar to
the first provided with a series of flexible pipes and taps or rubber tubes with spring
clamps corresponding with the series of tubes placed vertically beneath them as
hereinbefore explained.
By means of this arrangement the tubes can be readily filled with diluted acid
contained in the higher vessel or cistern and allowed to remain with their internal
surfaces only exposed to the action of the acid for the time necessary for the pickling.
When this operation is concluded the tabes simply require to be displaced or slightly
inclined in order to allow the pickling liquid to run out into the lower trough or

page_text: vessel after which the tubes can be removed and washed and dried before undergoing
the polishing process. When the whole of the liquid in the upper vessel has run
down into the lower vessel it can be elevated and returned to the upper vessel by
means of pumps or other suitable appliances.
Figure 3 of the accompanying drawings illustrates in vertical section an example
of an arrangement of apparatus for pickling tubes according to this Invention and
Figure 4 represents the same apparatus in a section taken in a plane perpendicular to
the plane of the section in figure 3.
This apparatus is constructed with two troughs or vessels A for the reception of the
liquid flowing from the tubes which are supplied with the pickling liquid from an
upper vessel A¹ provided with suitable valves or taps R. D are the tubes undergoing
treatment and resting on a shelf or support T covered with a sheet or cushion C of
india rubber. B is the working floor or platform-The method of operating with this
apparatus will be readily understood from the preceding description without further
explanation.
If necessary the external surfaces of the tubes may be coated with grease or other
acid proof protecting material in order to preserve them from the action of any
splashes or drops of acid that may accidentally come into contact with them.
Polishing the tubes--The tubes after pickling as hereinbefore described may be
hand polished in the ordinary way by means of leathers or other suitable appliances
acting with the addition of pulverized grit, emery powder, pumice stone or the like
but the operation is more quickly and economically performed by proceeding as
hereinafter described.
According to this Invention the polishing is effected by introducing into the tube,
which has been previously pickled and is firmly supported throughout its entire
length, a mandril made to fit the interior of the tube and of such diameter as to
enable it to exert a sufficiently powerful pressure to rapidly polish the internal surface
of the tube by friction. It will be understood that under these conditions it is
important for the tube to be very rigidly and firmly supported over its entire outer
surface so as to prevent it from giving way, under the strain of the internal pressure
exerted by the polishing mandril as it is drawn through the tube.
With this object the pickled tube is placed in a supporting case formed by a species
of mould made very strong and rigid being composed of two semi-cylindrical sections
having their internal surfaces accurately shaped in such a manner that when the
mould is closed its internal diameter is somewhat less than the external diameter of
the tube to be placed therein. One of the parts or sections of the mould may be
fixed preferably in a horizontal position, the other part being moveable and main-
tained in contact with the lower part by means of a hydraulic press or hydraulic
presses or other equivalent means.
The external diameter of the tube placed in the mould being slightly greater than
the internal diameter of the mould, the pressure exerted by the presses connected to
the mould is distributed over the whole of the external surface of the tube which is
thus very powerfully supported and compressed throughout its length.
This compression has the effect in the first place of truly straightening the tube and
taking out any curvature or irregularity that may result from the manufacture and in
the second place of rendering it absolutely impossible for the tube to give way or
burst under the internal pressure of the mandril. In order to maintain the parts of
the mould securely in their proper relative positions these parts are provided with
guides or projections and recesses carefully fitted so as to steady them during the
operation and a small shoulder is formed in the mould near one end to form a bearing
for the end of the tube and prevent it from becoming displaced longitudinally without
interfering with the movement or passage of the polishing mandril.
The said mandril usually made of tempered steel and polished is of a form exactly
corresponding with the internal shape of the tube and its diameter is slightly larger
than the internal diameter of the tube. This mandril is attached to the extremity of
a strong metal rod whose length exceeds that of the tube and which is actuated by
the piston of a hydraulic press or the clamps of a draw bench or the like.

page_text: "
1
It will be readily understood that under these conditions the.metal of the tube,
being powerfully compressed between the circumference of the mandril and the
interior of the mould, cannot be injured, but the unevenness or. roughness of its
internal surface is smoothed out and disappears under the action of the mandril the
pores of the metal being slightly compressed although the tube is elongated to.an
inconsiderable extent only. After this polishing process the mould is. opened by
raising the hydraulic presses and the finished tube can then be removed.
Figure 1 of the accompanying drawings represents partly in. section an example
of an arrangement of apparatus for polishing tubes according to this invention and
Figure 2 represents the apparatus in transverse sections taken on the lines. 1-2
and 3-4 figure 1.
}
In these figures, the tube to be polished is indicated. at D and the tivo. semi
cylindrical sections of the mould or case are marked FF the upper part F being
fixed and the lower part F moveable. M is the polishing mandril which is drawn
through the tube D by a piston R working in a cylinder H and provided with a
rod T connected to the mandril rod S by a clamp G. One cylinder and piston may
be combined with two tube supports or moulds as in the arrangement illustrated the
supports or moulds F.F receiving the tubes being maintained at the required distance
from the cylinder by suitable thrust pieces E E¹. The upper part F of the mould is
attached at A to the support E and the lower part F1 slides on the support E' at B.
The tube D being placed in position as indicated-at the right band end of figure 1
the two parts F F of the mould or case are forcibly pressed together by the action of
a hydraulic press P after which the mandril M is forced through the tube by the
action of the piston R and polishes the interior of the tube as herein before described
the tube being prevented from becoming displaced longitudinally by a flange or
collar a on the case F F¹.
The form arrangement and details of construction of the apparatus herein before
described may be modified in various ways. For example the two parts of the mould
may be connected together by any suitable mechanical means such as hoops, wedges,
keys, screws and the like and the moveable part of the mould may be jointed to the
stationary part by means of binges or it may be made entirely independent or
removeable from the said fixed part if preferred.
In place of employing a fixed or stationary mould or support for the pipes the
support may be rendered moveable by placing it on a carriage or on slides and
arranging it to bear against stops provided for the purpose in order to resist the
tractive strain exerted on it longitudinally by the action of the mandril. Or the
mandril may be stationary one end of the stem or rod to which it is attached being
secured to suitable stationary supports and the moving power is applied to the support
or case carrying the tube which is thus drawn over the mandril in place of drawing
the mandril through the tube the result being the same in both cases.
This process for rapidly polishing all descriptions of tubes can be employed with
advantage for polishing tubes prepared by the pickling process herein before described
or by any other ordinary or suitable pickling process whether the tube be pickled or
polished on its outer surface or not the essential feature of the process consisting in
supporting the tube externally throughout its length in order to provent any accidental
distortion or injury to the tube and to polish the internal surface by the great
pressure and friction of the mandril.
Having now particularly described and ascertained the nature of the said Inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:-
1. The methods of pickling and polishing the internal surfaces of metal tubes sub-
stantially as hereinbefore described.
2. The arrangement in which the tubes for picking are placed vertically or on end
upon a horizontal support fixed at or near the upper part of a suitable trough or vessel
and provided with a pad of rubber or other suitable material capable of making a tight
joint with the lower ends of the tubes which are then filled with acid liquid by means

page_text: of taps or nozzles provided for the purpose above their upper ends the liquid after-
wards being allowed to escape by simply rocking or inclining the tube so that it runs
down into a lower trough or vessel from which it can be subsequently pumped or
otherwise returned to the upper vessel substantially as herein before described.
3. The improved process for polishing the interiors of tubes with the employment
of. a. mould or case supporting and compressing the external surfaces of the tubes in
combination with a mandril of a form similar to but slightly larger than that of the
interior of the tubes, the said mandril being forced through the tubes so as to rapidly
polish the internal surface thereof substantially as hereinbefore described.
4.. A mould or case for supporting and compressing the external surfaces of the
tubes to be polished the said mould or case being composed of two semi-cylindrical
independent or hinged parts of a length suited for receiving the tubes and having an
internal diameter slightly less than the external diameter of the tubes the two parts
of the mould being forced together either by means of hydraulic presses or by the
action of hoops and wedges or other suitable mechanical appliances substantially as
hereinbefore described.
Dah 7th 1
1 1000
J. H. JOHNSON & Co.,
Agents.