Improvements in Thermostatic Steam Traps.
Year: 1893

page_text: Date of Application, 20th July, 1893
Complete Specification Left, 12th Apr., 1894-Accepted, 12th May, 1894
PROVISIONAL SPECIFICATION.
Improvements in Thermostatic Steam Traps.
1, EDWARD ETHEL GOLD, of Number 76 West 82nd Street, in the City,
County and State of New York, United States of America, Manufacturer, do
hereby declare the nature of this invention to be as follows:-
This invention relates to traps for the automatic discharge of condensed water from
steam mains, pipes or vessels. It pertains to that class of thermostatic steam traps
wherein the valve is, or is actuated by, a closed vessel of elastic metal containing
liquid which volatilizes at a temperature below that of the steam, and wherein
such vessel is enclosed within a casing with which the steam-pipe to be drained
communicates on one side the valve, and an outlet pipe or opening for discharging
the water is provided on the other side the valve. A trap of this type, and upon
which my present invention is most immediately an improvement, is shown in my
United States Patent No. 424,779, dated April 1, 1890.
In thermostatic traps of this character the valve remains closed by the expansion
of the elastic vessel containing the volatile liquid so long as that liquid is heated
above a certain degree, so that so long as the steam-pipe or vessel connecting with
the trap contains steam or hot water of condensation, the trap remains closed.
But when the condensation water has cooled to a certain temperature, and when
consequently the volatile liquid in the elastic vessel has likewise cooled to the
requisite extent, this vessel contracts and thereby opens the valve and permits the
accumulated water to flow out until hot water or steam begins to pass the trap,
whereupon by the re-heating of the volatile liquid the vessel is again expanded to
close the trap. The trap consequently operates at intervals to discharge the water
of condensation which continually accumulates in the steam-pipe or vessel, the
frequency of operation of the trap depending upon the rapidity with which its
thermo-expansion vessel is cooled after each re-heating by which it is expanded 10
close the valve.
The object of my present invention is to render the operation of the trap more
rapid in order that the water of condensation shall be drained off at more frequent
intervals, thereby avoiding the accumulation of so large a body of condensed water
as has heretofore occurred. To this end I so construct the shell or casing of the
trap within which the elastic or thermo-expansion vessel is enclosed as to cause
a current of air to continuously flow through the casing in contact with the thermo-
expansion vessel, in order that after being heated to close the trap it shall be
cooled more rapidly than heretofore in order to accelerate the reopening of the trap
and consequent discharge of the accumulated water. The casing of the trap is
accordingly provided with air inlet and outlet openings at opposite sides of the
vessel, preferably above and below, to facilitate the admission and discharge of
air flowing past the thermo-expansion vessel. A shield or deflector is provided
for preventing any dangerous outflow of hot water or steam through the air
openings.
Fig. 1 of the accompanying drawings is a side elevation of the preferred
construction of my improved steam trap;
Fig. 2 is a rear elevation thereof partly in vertical section ;
Fig. 3 is a vertical section through the centre of the trap on the line 3-3 in
Fig. 2;
Figs. 4 and 5 are elevations of the interior of the trap and inner side of its cover,
the latter being removed.

page_text: Fig. 6 is an elevation answering to Fig. 2 and showing a modified construction;
Fig. 7 is a vertical mid-section of the construction shown in Fig. 6;
Fig. 8 is an elevation answering to Fig. 4, but partly in vertical section and
showing a further modification;
The foregoing views illustrate my invention as applied in three different ways
to the construction of trap shown in my said Patent No. 424,779.
Fig. 9 is a vertical section illustrating the application of my invention to a
differently arranged thermostatic trap.
Referring first to Figs. 1 to 8, let A designate the casing of the steam trap,
which is preferably formed of cast metal in cylindrical shape, and having a threaded
hub B for connection with a pipe or vessel from which the water of condensation is
to be drained, and having also a discharge opening C at the lower side through
which the condensed water may escape from the trap. D is the cover of the trap
casing, which is united to the fixed part thereof by being cast with diametrically
opposite hooks E E adapted to engage with lugs or wings F F which are cast upon
the casing A and have inclined inner faces. Or the cover may be fastened to the
casing A in any other suitable manner.
Within the casing A is placed a thermo-expansion vessel G, which is a closed
vessel of elastic metal partly filled with some liquid which volatilizes at a
temperature below that of steam, and sealed. The front face of the vessel G is made
nearly flat in order that it may seat against a valve seat a, which is formed within
the inlet opening B, and which is preferably a ring of suitable elastic composition.
The vessel G is loosely enclosed within the casing, the latter being formed with
ribs to hold the vessel in place. To adjust it toward or from the valve seat, an
adjusting screw e is provided which engages the plate d on the back of the vessel.
The screw c is provided with a set-nut e. A coiled spring H is placed within the
casing in order to press the vessel G away from the valve seat a and to cause it to
open when cool against any slight vacuum that may exist in the steam pipe.
So far as described the construction is the same as that already disclosed in my
said Patent No. 424,779. I will now proceed to describe the improvements
introduced by my present invention.
As applied to the contruction of trap just described my invention is very simple.
Referring to the construction shown in Figs. 1 to 5, the trap casing is unchanged
except that an air outlet opening J is made through its front wall near the top,
that is, between the hub B and the roof of the casing. Over this opening is placed
a sheet K of some foraminous material, preferably wire gauze, the meshes of which
are sufficiently open to not materially obstruct the passage of a current of air. On
the casing is fastened by a screw for otherwise, a shield L which covers the
opening and serves to hold the foraminous sheet or strainer K in place over it.
This shield L is formed with notches at its edges constituting air holes or
openings gg, while at its bottom it stands clear of the hub B in order to form a
space or opening h.
Whenever the trap has been heated by escaping steam or hot water and has
consequently been closed by the expansion of the vessel G, which acts as a valve
and seats against the seat a, the heated walls of the casing and of the vessel G
serve to heat the air within the chamber of the casing and impart to it consequently
a tendency to rise. The heated air ascends within the casing and passes out
through the opening J into the space within the shield L, and thence escapes
through the holes g g. The place of the heated air is immediately taken by cold
air ascending through the bottom discharge opening C, as shown by the arrows in
Fig. 3, which becoming heated in turn passes out through the openings J and gg
as before. Thus a continuous current of air is maintained through the casing and
past the surfaces of the therino-expansion vessel G, all parts of which are exposed
to the air with the exception of the face in contact with and circumscribed by
the seat a. The other or exposed portions of the vessel consequently give out heat
to the current of air, while the portion enclosed within the seat remains in contact
with the steam or hot water within a pipe or vessel M, and remains heated thereby

page_text: so long as the steam or hot water remains thus against it. But upon the cooling
of the water, the vessel G being no longer kept heated thereby against the
cooling effect of the current of air, quickly cools and contracts, thereby opening
the valve and causing the accumulated and cold or cool condensed water to flow
out. By reason of the cooling effect of the current of air passing through the
trap casing, the heat is much more rapidly radiated or conducted from the
thermo-expansion vessel G than in the constructions heretofore employed wherein
the casing of the trap is closed except for the opening C beneath, so that no
circulation of air could take place therein.
My invention although it makes apparently but little change in the construction
of the trap, nevertheless results in a very important difference in the operation
thereof, since repeated tests show that under like circumstances as to external
temperature, degree of steam pressure, rapidity of condensation, etc., my improved
construction of trap will open in from one-fourth to one-fifth the time which is
required to operate the former construction. It results from this that a much less
mass of condensed water can accumulate within the pipes or radiators of the steam
heating system, and consequently that the heating apparatus is rendered much
more active and efficient, to such extent in fact that the amount of heating surface
can be considerably reduced for a given heat radiation under a given steam
pressure.
The purpose of the strainer K is to prevent dust, cinders, etc., entering the casing
and finding their way between the valve face of the vessel G and the valve seat.
This is important whenever the trap is to be used in connection with the steam
heating of railway cars, for which it is principally designed. The function of the
shield L is to prevent the blowing out of hot water or steam through the opening J,
which might otherwise occur when the trap opens, and which, particularly in case
of a trap mounted beneath a railway car, would be liable to scald a workman who
might be occupied beneath the car at the time, as often occurs. When the trap
opens, any hot water or steam that may be forced upward and pass out through the
opening J, will be intercepted by the shield L, and will escape sidewise through
the openings gg, and downwardly through the space or opening h, whereby the
force of the stream will be broken and the outflow will occur so dividedly and in
such directions as to amount to a mere harmless drenching of the front side of the
trap with water which will not be thrown to any distance beyond it.
The construction of the shield L as a hollow plate with notches in its sides
enables it to be utilized to hold the strainer K in place, the latter being bent over
the top of the casing and fastened between the casing and the upper part or
fastening lug of the shield, while its lower portion is confined between the notched
edges of the shield and the front face of the trap.
In the modified construction shown in Figs. 6 and 7, the casing A is formed
with the same air opening J1 as already described, and in addition a similar
opening J is formed through the cover D. In addition two other openings are
formed through both the front of the casing and the cover, so that on each side
there are three openings, as shown in Fig. 6. These are covered by strainers K' K'.
Shields L' L' are applied on both front and back, being fastened by screws f¹f'.
The shields are made wider than in the construction first described, extending in
the arc of a circle so as to cover the three holes, being formed with notches g¹,
in the flanges constituting their lower sides to provide for the escape of the air and
hot water or steam. This construction permits of a freer circulation of air than
that first described, since the air has approximately six times the area of opening
at the top through which to escape.
In Fig. 8 I have shown another construction wherein the air outlet opening,
here lettered J2, is formed through the roof of the casing, being covered by a
strainer K, and a shield L2, the latter being formed as a concave plate having
notches g in its edges, and fastened by one or more screws f².
While it is preferable that the air openings shall be so placed as to encourage
an upward circulation of air, yet this is not essential to my invention, since for use

page_text: on railway cars air openings placed horizontally opposite each other will be nearly
as effective, because during the time that the car is in motion an air current will
be induced laterally through the casing, provided only that the openings are
arranged in the direction that the air current caused by the movement of the car
tends to take. With openings so placed there will be less advantage to be gained
by reason of the air circulation when the car is standing still, whereas when the
openings are placed to establish an upward circulation of air, the effect is nearly as
great when the car is standing still as when it is in motion.
Often in applying a trap of the construction thus described to a car, it is imprac-
ticable to so apply it that it will stand erect, as shown in Figs. 1 to 8, the
arrangement of the piping often requiring the trap to be turned down horizontally
as shown in Fig. 9. When thus arranged the motion of the train will cause a
circulation of air through the trap casing in substantially the manner already
described. To facilitate this, the outlet opening C should be directed toward one
end of the car.
I have shown in Fig. 9 a construction of shield lettered L³ which
is preferable for a trap thus arranged. The shield is prolonged beyond the top of
the casing, which in this position becomes its left-hand end, and turned downwardly
to form both an air passage and a spout for discharging downwardly any water or
steam that may issue through the opening J.
Dated this 20th day of July 1893.
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Chartered Patent Agent.
COMPLETE SPECIFICATION.
Improvements in Thermostatic Steam Traps.
I, EDWARD ETHEL GOLD, of Number 76 West 82nd Street, in the City,
County and State of New York, United States of America, Manufacturer, 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 :-
This invention relates to traps for the automatic discharge of condensed water
from steam mains, pipes or vessels. It pertains to that class of thermostatic steam
traps wherein the valve is, or is actuated by, a closed vessel of elastic metal
containing liquid which volatilizes at temperature below that of the steam, and
wherein such vessel is enclosed within a casing with which the steam pipe to be
drained communicates on one side of the valve, and an outlet pipe or opening for
discharging the water is provided on the other side of the valve. A trap of this
type, and upon which my present invention is most immediately an improvement,
is shown in my United States Patent No. 424,779 dated April 1, 1890.
But
In thermostatic traps of this character the valve remains closed by the expansion
of the elastic vessel containing the volatile liquid so long as that liquid is heated
above a certain degree, so that as long as the steam pipe or vessel connecting with
the trap contains steam or hot water of condensation, the trap remains closed.
when the condensation water has cooled to a certain temperature, and when
consequently the volatile liquid in the elastic vessel has likewise cooled to the
requisite extent, the vessel contracts and thereby opens the valve and permits the
accumulated water to flow out until hot water or steam begins to pass the trap,
whereupon by the re-heating of the volatile liquid the vessel is again expanded to
close the trap. The trap consequently operates at intervals to discharge the water
of condensation which continually accumulates in the steam pipe or vessel, the
frequency of operation of the trap depending upon the rapidity with which its
therino-expansion vessel is cooled after each re-heating by which it is expanded to
close the valve.

page_text: The object of my present invention is to render the operation of the trap more
rapid in order that the water of condensation shall be drained off at more frequent
intervals, thereby avoiding the accumulation of so large a body of condensed water
as has heretofore occurred. To this end I so construct the shell or casing of the
trap within which the elastic or thermo-expansion vessel is enclosed as to cause a
current of air to continuously flow through the casing in contact with the thermo-
expansion vessel, in order that after being heated to close the trap it shall be cooled
more rapidly than heretofore in order to accelerate the re-opening of the trap and
consequent discharge of the accumulated water. The casing of the trap is
accordingly provided with air inlet and outlet openings at opposite sides of the
vessel, preferably above and below, to facilitate the admission and discharge of air
flowing past the thermo-expansion vessel. A shield or deflector is provided for
preventing any dangerous outflow of hot water or steam through the air openings.
Fig. 1 of the drawings left with the Provisional Specification is a side elevation
of the preferred construction of my improved steam trap;
Fig. 2 is a rear elevation thereof partly in vertical section;
Fig. 3 is a vertical section through the centre of the trap on the line 3--3 in
Fig. 2;
Figs. 4 and 5 are elevations of the interior of the trap and inner side of its cover,
the latter being removed;
Fig. 6 is an elevation answering to Fig. 2 and showing a modified construction ;
Fig. 7 is a vertical mid-section of the construction shown in Fig. 6;
Fig. 8 is an elevation answering to Fig. 4 but partly in vertical section and
showing a further modification;
The foregoing views illustrate my invention as applied in three different ways to
the construction of trap shown in my said Patent No. 424,779.
Fig. 9 is a vertical section illustrating the application of my invention to a
differently arranged thermostatic trap.
Referring first to Figs. 1 to 8 let A designate the casing of a steam trap, which
is preferably formed of cast metal in cylindrical shape, and having a threaded
hub B for connection with a pipe or vessel from which the water of condensation is
to be drained, and having also a discharge opening C at the lower side through
which the condensed water may escape from the trap. D is the cover of the trap
casing, which is united to the fixed part thereof by being cast with diametrically
opposite hooks E E adapted to engage with lugs or wings F F which are cast upon
the casing A and have inclined inner faces. Or the cover may be fastened to the
casing A in any other suitable manner.
Within the casing A is placed a thermo-expansion vessel G, which is a closed
vessel of elastic metal partly filled with some liquid which volatilizes at a tempera-
ture below that of steam, and sealed. The front face of the vessel G is made
nearly flat in order that it may seat against a valve seat a, which is formed within
the inlet opening B, and which is preferably a ring of suitable elastic composition.
The vessel G is loosely enclosed within the casing, the latter being formed with
ribs bb to hold the vessel in place. To adjust it toward or from the valve seat, an
adjusting screw c is provided which engages the plate on the back of the vessel.
The screw c is provided with a set nut e. A coiled spring H is placed within the
casing in order to press the vessel G away from the valve-seat a and to cause it to
open when cool against any slight vacuum which may exist in the steam pipe.
So far as described the construction is the same as that already disclosed in my
said Patent No. 424,779. I will now proceed to describe the improvements
introduced by my present invention.
As applied to the construction of trap just described my invention is very simple.
Referring to the construction shown in Figs. 1 to 5, the trap casing is unchanged
except that an air outlet opening J is made through its front wall near the top,
that is, between the hub B and the roof of the casing. Over this opening is placed
a sheet K of some foraminous material, preferably wire gauze, the meshes of which
are sufficiently open to not materially obstruct the passage of a current of air. On

page_text: the casing is fastened by a screw for otherwise, a shield L which covers the
opening J and serves to hold the foraminous sheet or strainer K in place over it.
This shield L is formed with notches at its edges constituting air holes or
openings gg, while at its bottom it stands clear of the hub B in order to form a
space or opening h.
Whenever the trap has been heated by escaping steam or hot water and has
consequently been closed by the expansion of the vessel G, which acts as a valve
and seats against the seat a, the heated walls of the casing and of the vessel G
serve to heat the air within the chamber of the casing and impart to it consequently
a tendency to rise. The heated air ascends within the casing and passes out
through the opening J into the space within the shield L, and thence escapes
through the holes gg. The place of the heated air is immediately taken by cold
air ascending through the bottom discharge opening C, as shown by the arrows in
Fig. 3, which becoming heated in turn passes out through the openings J and g
as before. Thus a continuous current of air is maintained through the casing and
past the surfaces of the thermo-expansion vessel G all parts of which are exposed
to the air with the exception of the face in contact with and circumscribed by the
.seat a. The other or exposed portions of the vessel consequently give out heat to
the current of air, while the portion enclosed within the seat remains in contact
with the steam or hot water within a pipe or vessel M, and remains heated thereby
so long as the steam or hot water remains thus against it. But upon the cooling
of the water, the vessel G being no longer kept heated thereby against the cooling
effect of the current of air, quickly cools and contracts, thereby opening the valve
and causing the accumulated and cold or cool condensed water to flow out. By
reason of the cooling effect of the current of air passing through the trap casing,
the heat is much more rapidly radiated or conducted from the thermo-expansion
vessel G than in the construction heretofore employed wherein the casing of the
trap is closed except for the opening C beneath, so that no circulation of air could
take place therein.
My invention although it makes apparently but little change in the construction
of the trap, nevertheless results in a very important difference in the operation
thereof, since repeated tests show that under like circumstances as to external
temperature, degree of steam pressure, rapidity of condensation, etc., my improved
construction of trap will open in from one-fourth to one-fifth the time which is
required to operate the former construction. It results from this that a much less
mass of condensed water can accumulate within the pipes or radiators of the steam
heating system, and consequently that the heating apparatus is rendered much
more active and efficient, to such extent in fact that the amount of heating surface
can be considerably reduced for a given heat radiation under a given steam
pressure.
The purpose of the strainer K is to prevent dust, cinders, etc., entering the casing
and finding their way between the valve face of the vessel G and the valve seat.
This is important whenever the trap is to be used in connection with the steam
heating of railway cars, for which it is principally designed. The function of the
shield L is to prevent the blowing out of hot water or steam through the opening J,
which might otherwise occur when the trap opens, and which, particularly in case
of a trap mounted beneath a railway car, would be liable to scald a workman who
might be occupied beneath the car at the time, as often occurs.
When the trap
opens, any bot water or steam that may be forced upward and pass out through the
opening J, will be intercepted by the shield L, and will escape sidewise through
the openings g g, and downwardly through the space or opening h, whereby the
force of the stream will be broken and the outflow will occur so dividedly and in
such directions as to amount to a mere harmless drenching of the front side of the
trap with water which will not be thrown to any distance beyond it.
The construction of the shield L as a hollow plate with notches in its sides
enables it to be utilized to hold the strainer K in place, the latter being bent over
the top of the casing and fastened between the casing and the upper part or

page_text: fastening lug of the shield, while its lower portion is confined between the notched'
edges of the shield and the front face of the trap.
In the modified construction shown in Figs. 6 and 7 the casing A is formed with
the same air opening J'as already described, and in addition a similar opening J
is formed through the cover D. In addition two other openings are formed
through both the front of the casing and the cover, so that on each side there are
three openings, as shown in Fig. 6. These are covered by strainers K' K¹.
Shields L' L are applied on both front and back, being fastened by screws f¹f..
The shields are made wider than in the construction first described, extending in
the arc of a circle so as to cover the three holes, being formed with notches g',
in the flanges constituting their lower sides to provide for the escape of the air and
hot water or steam. This construction permits of a freer circulation of air than
that first described, since the air has approximately six times the area of opening
at the top through which to escape.
In Fig. 8 I have shown another construction wherein the air outlet opening, here
lettered J, is formed through the roof of the casing, being covered by a strainer K²,.
and a shield L2, the latter being formed as a concave plate having notches 9² in its
edges, and fastened by one or more screws f³.
While it is preferable that the air openings shall be so placed as to encourage an
upward circulation of air, yet this is not essential to my invention, since for use on
railway cars air openings placed horizontally opposite each other will be nearly as
effective, because during the time that the car is in motion an air current will be
induced laterally through the casing, provided only that the openings are arranged
in the direction that the air current caused by the movement of the car tends to
take. With openings so placed there will be less advantage to be gained by reason
of the air circulation when the car is standing still, whereas when the openings are
placed to establish an upward circulation of air, the effect is nearly as great when
the car is standing still as when it is in motion.
Often in applying a trap of the construction thus described to a car, it is
impracticable to so apply it that it will stand erect, as shown in Figs. 1 to 8, the
arrangement of the piping often requiring the trap to be turned down horizontally
as shown in Fig. 9. When thus arranged the motion of the train will cause a
circulation of air through the trap casing in substantially the manner already
described. To facilitate this, the outlet opening C should be directed toward one
end of the car. I have shown in Fig. 9 a construction of shield lettered L³ which
is preferable for a trap thus arranged. The shield is prolonged beyond the top of
the casing, which in this position becomes its left-hand end, and turned downwardly
to form both an air passage and a spout for discharging downwardly any water or
steam that may issue through the opening J.
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 a steam trap of the character described, the construction of the enclosing
casing with opposite openings at top and bottom for admitting of an upward
circulation of air through it around the thermo-expansion vessel, so that the air
heated by radiation within the said casing may escape upwardly and its place be
taken by cold air to hasten the cooling of the said vessel and thereby accelerate
the opening of the trap, substantially as specified.
2. The construction of such casing with opposite air openings for promoting a
circulation of air through it to hasten the cooling of the enclosed vessel, and with
a shield over such air opening adapted to intercept any hot water or steam that
may issue therefrom, and direct it downward or laterally and break its force, that
it may do no damage, substantially as specified.
3. In combination with such casing A, having inlet B, outlet C, and air
opening J, a shield L over the said air opening, constructed with lateral and
bottom openings, substantially as specified.

page_text: 4. A steam trap comprising a casing A, having inlet B, outlet C, and air
opening J, and a thermo-expansion vessel G inclosed in the said casing, combined
with a strainer K over the said air opening, and a shield L fastened to the casing
over the strainer to hold the latter in place, and having lateral notches g g to form
openings for escape of air or hot water, substantially as set forth.
Dated this 12th day of April 1894.
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Chartered Patent Agent.