Improvements in Steam Traps.
Year: 1894

page_text: Date of Application, 19th Feb., 1894
Complete Specification Left, 16th Nov., 1894-Accepted, 19th Jan., 1895
Improvements in Steam Traps.
I, GEORGE JACKSON CHURCHWARD, Engineer, of 13 Glo'ster Terrace, Swindon,
in the County of Wilts, do hereby declare the nature of this invention to be as
follows:-
My invention relates to improvements in steam traps, or apparatus for
automatically discharging cold air and the water of condensation from the couplings
pipes, heaters, etc. of the steam heating apparatus in railway coaches.
My invention also applies to steam traps for steam pipes, engines, drying
cylinders, and heating coils in general use.
My invention is intended in certain applications to be applied as an adjunct and
improvement to my Patent 5267 of March 1893.
The float described in my Specification No. 5267 of 1893 will not discharge
cold air from steam pipes, etc. when steam is first admitted to the apparatus, but by
the application of the thermostat, about to be described, to the lower part of my
float trap instead of the cock K shewn on the drawing of Specification No. 5267
of 1893, this difficulty is overcome.
In a case or chamber I place a quantity of stearic acid, wax, petroleum residuum,
or similar substance having a high coefficient of expansion under heat.
Through the mass of this substance I conduct the tube or pipe or passage for the
discharge of cold air and the water of condensation, and a part of this tube or pipe
or passage, I construct of india-rubber (vulcanized caoutchouc) which is specially
compounded with other substances to enable it the better to resist the heat of the
steam.
Now with the parts arranged as described 1 obtain a steam trap in which the
elastic portion of the passage or outlet for air and the water of condensation is
automatically closed by the pressure of the expanding substance when heated by
the presence of the steam.
I make the walls of this elastic tube, or pipe, or passage of varying thickness aud
strength so that when the pressure of the expanding substance is brought to bear,
the elastic pipe, tube or passage is closed against the passage of steam at its weakest
point first, so leaving a further portion of its length to be closed if necessary by a
further expansion of the stearic acid, wax, petroleum residuum, or other substance.
I design this particular section of the elastic tube or passage in order to prevent
the bursting or straining of the case, chamber, or other part of the apparatus when
a higher temperature is attained than that at which the passage is first closed.
This object is usually attained in thermostats by maintaining air or other elastic
gas or vapour in the case or chamber containing the expanding substance, which of
course causes the apparatus to be too large and cumbersome for some applications.
By my passage of graduated strength or resistance, I am enabled to use an
incompressible material for the expanding substance.
In thermostatic steam traps a difficulty is generally experienced in getting the
I deal
expanding mixture or material heated quickly enough by the issuing steam.
with this difficulty by placing coils of copper or brass wire gauze in the case or
chamber in such a manner that the expanding mixture or material is minutely
subdivided by the strands of wire which conduct the heat of the issuing steam
quickly into the mass.

page_text: For this purpose I sometimes arrange in the case webs or wings of metal of
high conductivity, joined to the metal of the case or chamber, in order to quickly
conduct the heat from issuing steam into the stearic acid, wax, petroleum residuum,
or other expanding material.
For the purpose of adjustment I provide a set screw in the case or chamber in the 5
usual way.
Dated this 17th day of February 1894.
improvements in Steam Traps.
I, GEORGE JACKSON CHURCHWARD, Engineer, of 13, Glo'ster Terrace, Swindon,
in the County of Wilts, 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 traps, or apparatus for
automatically discharging cold air and the water of condensation from the couplings,
pipes, heaters, etc. of steam heating apparatus in railway carriages.
My invention also applies to steam traps for steam pipes, engines, drying
cylinders, heating coils, etc. in general use.
My invention is intended in certain applications to be applied as an adjunct and
improvement to the steam trap described in Specification No. 5267 of A.D. 1893,
which latter will not discharge cold air from steam pipes, etc., when steam is first
admitted, but by the application of the apparatus, about to be described, to the
lower part of the float trap instead of the cock K shewn on the former Specification
above mentioned the difficulty is overcome.
On the sheet of drawings herewith,
Fig. 1 represents the general outline of the thermostatic steam trap about to be
described.
Fig. 2 is a vertical section of the same shewing flexible tube, strengthening
needles, expanding substance, wire gauze, and adjusting screw, about to be
described.
Fig. 3 is a plan of the thermostatic steam trap, looked at from above.
Fig. 4 is a vertical section of the thermostatic steam trap shewing the solid india-
rubber combination of flexible tube G with expanding substance H, which I prefer
to the arrangement shewn by Fig. 2, and is more particularly described below.
Fig. 5 is a horizontal section of the solid block of compound india rubber
combination of flexible tube and expanding substance described below.
2.
In a case or chamber lettered A on drawings herewith, I place a quantity of
stearic acid, wax, petroleum residuuma, gutta-percha, india-rubber, or similar
substances, having a high coefficient of expansion under the application of heat.
Of the various substances I prefer gutta-percha and india-rubber.
When I use the term india-rubber, I mean caoutchouc compounded with all or
any of the following:-sulphur, zinc oxide, linseed oil, to enable it the better to
resist the heat of steam.
Through the mass of this substance, lettered B on the drawings herewith, I
conduct the tube or pipe or passage C, for the discharge of cold air and the water
of condensation and a part of this passage, lettered D on drawings, I construct of
india-rubber (vulcanized caoutchouc), which is specially compounded with other
substances to enable it the better to resist the heat of the steam.
With the parts arranged as described I obtain a steam trap in which the elastic
portion D of the passage or outlet for cold air and the water of condensation, is

page_text: automatically closed by the pressure of the expanding substance B when heated by
the presence of steam.
I make the walls of the elastic portion D of the passage C of varying thickness
anl strength, so that when the pressure of the expanding substance B is brought to
bear the elastic portion of the passage is closed against the issue of steam at its
weakest point first so leaving a further portion of its length to be closed, if
necessary, by a further expansion of the expanding substance B.
I design this particular action of the elastic passage in order to prevent the
bursting or straining of the case or other part of the trap when a higher temperature
is attained than that at which the elastic part D of the passage C is first closed.
In the walls of the lower portion of the elastic tube D I arrange small wires or
needles E, E. I design these wires or needles for the purpose of supporting the
walls of the lower portion of the elastic tube D when the pressure of the steam
and the expanding substance B, after closing the passage, tend to force the walls of
the elastic tube D down the lower pipe C.
For the purpose of adjustment I provide a
chamber A.
<<
"
set screw F in the case or
By the use of the elastic tube or passage D having its walls of graduated
strength or resistance I am enabled to employ an incompressible material for the
expanding substance.
In thermostatic steam traps a difficulty is generally experienced in getting the
expanding mixture or material heated quickly enough by the issuing steam.
I sometimes deal with this difficulty by placing coils of brass or copper wire
gauze in the case or chamber in such a manner that the expanding material is
minutely subdivided by the strands of wire which conduct the heat of the issuing
steam quickly into the mass.
For some applications I combine the elastic pipe or tube, lettered G, Fig. 4 on
drawings, with the mass of an expanding substance H, composed of india-rubber
specially compounded with other substances to enable it the better to resist the heat
of the steam.
By this means I obtain a combination of the elastic tube or pipe with an
expanding mass in one block of compound india-rubber.
I make the elastic tube or passage through this block of compound india-rubber
of an oval section as shewn at J, Fig. 5.
This enables the elastic tube to be closed by the expanding mass of compound
india-rubber much more easily than would be possible if the passage were round
in section.
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 :-
(1.) In a steam trap the combination of an elastic pipe or passage, for the issue
of cold air and water, composed of compounded india-rubber and having its walls
of varying strength, thickness or section, with an expanding mass of gutta-percha,
compounded india-rubber or similar substance, all constructed for the purpose and
acting in the manner shewn and described.
Dated this Fifteenth day of November 1894.
GEORGE JACKSON CHURCH WARD.