Improvements in Steam Traps.
Year: 1896

page_text: Date of Application, 13th Jan., 1896
Complete Specification Left, 13th Oct., 1896-Accepted, 14th Nov., 1896
PROVISIONAL SPECIFICATION.
Improvements in Steam Traps.
We, JOHN ISAAC THORNYCROFT, of Eyot Villa, The Mall, Chiswick, in the County
of Middlesex, F.R.S., and JOHN EDWARD THORNYCROFT, of the same address,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to a construction of steam trap, escape of water from which
is controlled by means of an arrangement of two valves, the larger of which controls
a passage whose inlet end opens at a suitable level into a float-containing vessel
or chamber. The larger valve has through it a steam passage normally closed by
the smaller valve which is carried by and below the float, the arrangement being
such that when the water in the vessel or chamber rises sufficiently, the passage
through the larger valve will be opened by the rising of the float and consequent
lifting of the smaller valve, whereupon water will descend from above the larger
valve, and it will be opened by pressure of water against its lower surface, thus
allowing water to escape from the float chamber. As the water level in that chamber
falls, the small valve will be closed by the descent of the float, and so will the
larger valve. The weight of the float is, or may be, partly supported by a spring
to which the float may be suspended and which spring is furnished with an adjusting
device such as a screw with hand-wheel-the screw passing through a suitable
stuffing box. In one arrangement the larger valve resembles a piston and fits
easily in a cylindrical chamber so that there may be a slight leakage past it. It
is provided at its lower side with a stem arranged to work in a guide and through
which is formed the passage that is controlled by the smaller valve which may
conical and is at the lower end of a vertical rod depending from the float and
passing down through the top of the valve chamber. The passage leading from
the float chamber communicates with an annular chamber located below the float
chamber and below the larger valve, which, when closed, forms the top of such
annular chamber, the inner wall of which forms part of the water outlet passage,
whilst the upper edge of such inner wall constitutes the valve seat.
Dal 19th Jos of Tonnary 1896
Improvements in Steam Traps.
We, JOHN ISAAC THORNYCROFT, of Eyot Villa, The Mall, Chiswick, in the County
of Middlesex, F.R.S. and JOHN EDWARD THORNYCROFT, of the same address,
Engineer, 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 a construction of steam trap, escape of water from which

page_text: is controlled by means of an arrangement of two valves, the larger of which controls
a passage whose inlet end opens at a suitable level into a float containing vessel or
chamber (hereinafter called the float chamber). The larger valve has through it a
steam passage normally, closed by the smaller valve which is carried by and below
the float, the arrangement being such that when the water in the float chamber
rises sufficiently, the passage through the larger valve will be opened' by the rising
of the float and consequent lifting of the smaller valve, whereupon water will
descend from above the larger valve, and it will be opened by pressure of water
against its lower surface, thus allowing water to escape from the float chamber.
As the water level in that chamber falls, the small valve will be closed by the
descent of the float, and so will the larger valve. The weight of the float is, or
may be; partly supported by a spring to which the float may be suspended and
which spring is furnished with an adjusting device such as a screw with hand-wheel,
the screw passing through a suitable stuffing box.
Fig. 1 of the accompanying drawings shows in vertical section one construction
of steam trap according to this invention, and Fig. 2 shows in elevation a part of
such trap.
1 is a vessel or chamber containing a float 2 and into which water of condensation
can drain from steam pipes 4 connected therewith. 5 is a discharge passage
communicating with the float containing chamber 1 and with an annular chamber 5.
located below the float chamber and below a valve 6, herein called the larger valve,
which, when closed, forms the top of such annular chamber the inner wall 5 of
which forms part of the water outlet passage 5, whilst the upper edge of such
inner wall constitutes the valve seat. The larger valve 6 resembles a piston and
fits easily in a cylindrical chamber 7 so that there will be a slight leakage past
it. It is provided at its lower side with a stem 6ª arranged to work in a guide 8
so that its lower annular surface exposed to pressure will be. smaller than its upper
surface. Through the said valve 6 is formed a passage 6 controlled by the smaller
valve 9 which may be conical and is at the lower end of a vertical rod 10
depending from the float 2 and passing down through the top 7" of the valve
chamber.
The arrangement as will be seen is such that upon water rising in the float
chamber to a predetermined level say xa, for which the float has. been previously
adjusted, the float will rise and lift the small valve 9 away from its seat and open
the passage 6 through the larger valve 6. The water that will have collected
above the larger valve will then escape through the said passage and by relieving
the upper side of the larger valve of pressure will permit this valve to be raised
by the water pressure on that part of its lower surface above the annular chamber 5".
The valve being thus opened water will be discharged from the chamber 1 through
the passage 5, chamber 5 and passage 5 until, by the falling of the float, the
small valve 9 again closes the passage 6 and permits the pressure of the water
leaking past the valve and acting upon the upper side of the valve to exceed the
water pressure on the lower side of the valve, whereupon the said valve will
automatically close and prevent further discharge of water until the water collecting
in the float chamber again attains the predetermined level when the above described
operation will be repeated.
The lower part of the float chamber in which the valve chamber 7 and connected
passages 5, 5 5 and annular chamber 5ª are located may conveniently be made in
two parts 1, 1 held together by a centrally arranged adjustable screw 11 that bears
against the bottom part 1 and is carried by a stirrup shaped bar 12 carried by the
upper part 1 of the two parts 1 1, the arrangement being such as to admit of the
two parts being readily disconnected for inspection of the valves and other internal
parts and of the saidi parts being readily replaced for re-use.
13 is a spring for partly supporting the weight of the fibat 2. It is carried by a
screw threaded rod 14 that passes through a stuffing box 15 and through a nut 16
with hand. wheel 16, and is provided with a handle 17 by which it can be prevented
from rotating the arrangement being such that the proportion of the weight of the

page_text: float that is carried by the spring and attached parts can be readily varied to suit
requirement.
Fig. 3 is a side elevation and Fig. 4 a sectional plan, showing a modification in
which instead of placing the float 2 in a lateral extension 1° of the float chamber 1
which is made large to allow of a considerable quantity of water of condensation
collecting therein, as shown in Fig. 1, the float 2 is placed in a chamber 1* that is.
made separately from the chamber 1 to which it is connected by tubular connec-.
tions 1, 1. In this case the annular chamber 5* controlled by the larger valve 6 may
conveniently be connected with the bottom of the chamber 1 by a pipe 5*.
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. A steam trap wherein the escape of water is controlled by two valves, one of
which, the smaller, is operated by a float and controls a passage through the other or
larger valve which controls a water discharge passage in communication with the
float chamber, the arrangement being such that when the water in the float.
chamber rises sufficiently, the passage through the larger valve will be opened by the
lifting of the smaller valve and by relieving the upper side of the larger valve from
pressure will permit this valve to be opened by the pressure of water against its lower
side, thus allowing water to escape from the float chamber until by the falling of the
float and closing of the said passage, the pressure on the upper side of the larger valve.
is allowed to again exceed that on its lower side and close the said valve, substantially
as described.
2. Steam traps constructed, arranged and operating substantially as hereinbefore
described with reference to and shown in Figs. 1 and 2, or modified according to.
Figs. 3 and 4.