Year: 1899

page_text: Date of Application, 16th Mar., 1899
Complete Specification Left, 12th Dec., 1899-Accepted, 24th Feb., 1900
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention to be as follows:
:―
This invention relates to an arrangement for reducing pressure which is depen-
dent for its effect upon the co-operation of two valves. These valves surround
each other and are so arranged that the outer, larger valve, when in its terminal
position, is not relieved from pressure, while the smaller, inner valve is so
relieved constantly, with the result that its operation is at all times easy and
that, whenever it opens, it relieves the larger valve. By this arrangement
various drawbacks with which the pressure reducing devices hitherto known have
been attended, are obviated. One result arising therefrom is the great sensi-
tiveness to pressure which this construction imparts to the apparatus, so that
the slightest fluctuations of pressure will, in consequence, set the same into
operation. Moreover, the tightness of the valves is reliably maintained.
According to one form in which these valves may be constructed the steam or
other fluid of which the pressure is to be reduced, enters an inlet in the casing
of the device, while the steam or fluid at a reduced pressure passes out through
an outlet in the said casing. The desired reduced pressure prevailing at the
outlet is transmitted through a port or passage into the space over a piston
which, owing to the weighted lever, offers an adequate amount of resistance or
counter-pressure.
The two valves, placed concentrically one within the other are closed in this posi-
tion. The outer, larger valve,-in consequence of the fact that reduced pressure
prevails at the outlet, is pressed down upon its seat by the full difference of
pressure existing between the inlet and outlet. The smaller valve, arranged con-
centrically within the outer valve, is relieved from pressure in all cases, includ-
ing that in which it occupies its terminal position, as the dimensions of the
aperture wherein the cone or plug is guided at the top, and of the passage of
the valve below respectively are alike, and as the space over the inner valve or
pressure relieving chamber communicates with the space below the said valve
through a port. The smaller valve, therefore, is kept closed, not by the differ-
ence of pressure, but only by the power of the piston.
Should the pressure at the outlet become slightly reduced, the piston will be
forced up by the weight of the lever, and the small valve, which even in its
terminal position is free from any pressure will, thereby be opened without
meeting with any resistance. The steam or the like may now pass from the
inlet, through the inner valve opening into the space cominunicating therewith,
and, inasmuch as the port in the outer valve is much smaller than the passage
of the small valve, there will now prevail in the said space the same pressure

page_text: as at the inlet. The larger valve also, therefore, is now relieved from pressure.
Owing to the fact that the small valve, on first rising for a certain distance,
comes into contact with the screw-threaded part of its guide or cap, the larger
valve cone or plug, as the piston continues to ascend, is raised with such piston,
so that now the opening of the outer, larger valve is available for the passage
of the steam or the like.
The employment of the inner valve, which even in its final position is entirely
free from pressure, while it is only after the unimpeded opening of this valve
that the larger valve-which until then was not so relieved, becomes a relieved
valve, is that which constitutes the novel feature of the present invention. In
all constructions previously known the inner smaller valve was not freed from
pressure; the disadvantage arising from which fact will be apparent from the
following statement:
Were the pressure-reducing apparatus in this case unprovided with a screw-
threaded portion, and a relieving port in the small valve and were the small
valve, accordingly, not relieved from pressure, the full pressure at the inlet
would bear upon the said small valve; in other words, the difference of pressure
in inlet and outlet would press down this valve, also, upon its seat. Hence the
small valve could only open when the pressure at the outlet was reduced suffi-
ciently to allow the piston to exercise a pressure corresponding to the difference
of pressures between the outlet and inlet passages. Besides, the said small
valve, in its closing movement, would be shut by the steam rushing from the
inlet, like a back-pressure valve; the consequence being that the pressure reduc-
ing apparatus would not open and close at the identical degree of reduced pres-
sure, but that continually recurring fluctuations of pressure would be observable
in the course of operation of the apparatus. Indeed this is exactly what does
happen in the apparatus of this class as hitherto constructed.
The construction of a permanently relieved valve, characterized by the pro-
vision of the pressure relieving chamber and the port, is not novel as such.
Valves of this description which were pressure-free even in their terminal posi-
tion, have been employed before, but only as a single cut-off device. For this
purpose, however, such a valve cannot be recommended as in that case it natu-
rally has to be enlarged in proportion to the full aperture of the steam-passage
of the reducing apparatus. In large valves of this description there is always
the serious draw back to be reckoned with, that they do not close tightly enough,
for the diameter of the space or pressure reducing chamber must always, in
diameter, be equal to the passage in the main valve seat; and at the circum-
ference of the guide at the top where the valve slides in the pressure reducing
chamber the want of tightness is also correspondingly great; with the result
that an objectionable increase of pressure takes place behind the apparatus, the
closed valve notwithstanding. Besides in that case the power of the piston,-
which for practical reasons (i.e. on account of the expansion) should be of small
size, is sufficient to secure the valve firmly enough upon its seat.
In the reducing apparatus herein described, wherein the small valve serves
only for the purpose of relieving the main valve-body from pressure, the dimen-
sions of the aperture of the pressure reducing chamber are so small, in con-
parison to the full aperture, that the lack of tightness referred to remains with-
out any material effect upon the reduced pressure. Besides, the small valve is
so small, in proportion to the piston, that even a minimum increase of pressure
suffices to tightly close it in the space.
Now it is certainly true that the small valve might be constructed as a non-
relieved valve, making it so small however that it may only be affected to a
minimum degree by the drawback above mentioned. But in that case the large
valve could not be relied upon to become relieved from pressure when required.
as even though the perforation were wanting, the leakages through the large
valve (especially after protracted use and from the consequent wear) would
inevitably become to great in proportion to the aperture in the valve,

page_text: From the foregoing remarks it will be seen that this invention consists of the
construction of an outer valve, which, in its terminal position, is pressed down
upon its seat by the full difference of pressure, with a small valve, arranged to
remain within and concentric with the said large or outer valve, and being con-
sequently relieved from pressure even in its final position; the main valve, how-
ever being relieved from pressure only by the opening movement of the small
valve; with the object of ensuring the ready opening and tight closing of the
valve arrangement by means of a piston, made small in proportion to the full
sectional area of the aperture of the pressure-reducing apparatus; and also for
the purpose of reducing the fluctuations of pressure on the delivery or outlet
side to a minimum.
Dated this 16th day of March 1800
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent. Agents,
45, Southampton Buildings, in the County of Middlesex, 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 an arrangement for reducing pressure which is depen-
dent for its effect upon the co-operation of two valves. These valves surround
each other and are so arranged that the outer, larger valve, when in its terminal
position, is not relieved from pressure, while the smaller, inner valve is so
relieved constantly, with the result that its operation is at all times easy and
that, whenever it opens, it relieves the larger valve. By this arrangement
various drawbacks with which the pressure reducing devices hitherto known have
been attended, are obviated. One result arising therefrom is the great sensi-
tiveness to pressure which this construction imparts to the apparatus, so that
the slightest fluctuations of pressure will, in consequence, set the same into
operation. Moreover, the tightness of the valves is reliably maintained.
.
The accompanying drawings represent one form in which these valves may be
constructed. The steam or other fluid of which the pressure is to be reduced
enters the inlet P in the casing of the device in the direction of the arrow
while the steam or fluid at a reduced pressure passes out through an outlet P¹.
The apparatus is shown in that terminal position which it occupies when the
desired reduced pressure, corresponding to the lever-load at H prevails_at P¹.
This pressure is transmitted through a port or passager into the space Rover
a piston K which, owing to the weighted lever H, offers an adequate amount of
resistance or counter-pressure.
The two valves a and b placed concentrically one within the other are closed
in this position. The outer, larger valve a, in consequence of the reduced
pressure prevailing at the outlet, is pressed down upon its seat by the full
difference of pressure existing between the inlet P and outlet P¹. The smaller
valve b, arranged concentrically within the valve a, is relieved from pressure in
all cases, including that in which it occupies its terminal position, as the dimen-
sions I and II of the aperture wherein the cone or plug is guided at the top,
and of the passage of the valve b, respectively are alike, and as the space R³
over the inner valve or pressure relieving chamber communicates with the space
below the said valve 6 through a porty. The smaller valve b, therefore, is

page_text: kept closed, not by the difference of pressure, but only by the power of the
piston K.
Should the pressure at the outlet. P¹ become slightly reduced, the piston will
be forced up by the weight of the lever H, and the small valve which even
in its terminal position is free from any pressure-will, thereby be opened with-
out meeting with any resistance. The steam or the like may now pass from
the inlet P, through the inner valve opening II into the space R³ communi-
cating therewith, and, inasmuch as the port in the outer valve is much smaller
than the passage 11 of the small valve b, there will now prevail in the said
space R the same pressure as at the inlet P. The larger valve also, therefore,
is now relieved from pressure. Owing to the fact that the small valve b, on
first rising for a certain distance, comes into contact with the screw-threaded
part S of its guide or cap and as the piston K continues to ascend, the larger
valve cone or plug is raised with such piston, so that now the full aperture of
The valve arrangement is available for the passage of the steam or the like.
The employment of the inner valve, which even in its final position is
entirely free from pressure, while it is only after the unimpeded opening of
this valve that the larger valve a, which until then was not so relieved,-
becomes a relieved valve, is that which constitutes the novel feature of the
present invention. In all constructions previously known the inner, smaller
valve was not freed from pressure; the disadvantage arising from which fact
will be apparent from the following statement:-
Were the pressure-reducing apparatus in this case unprovided with a screw-
threaded portion, such as S, and a relieving port, such as y; and were the valve b,
accordingly, not relieved from pressure, the full pressure at the inlet P would,
in the position illustrated in the drawing, bear upon the said small valve 6; in
other words, the difference of pressure P-P¹ would press down this valve 6 also
upon its seat. Hence the small valve 6 could only open when the pressure at
the outlet Pi was reduced sufficiently to allow the piston K to exercise a pres-
sure corresponding to the difference of pressures between the outlet and inlet
passages. Besides, the said valve 6, in its closing movement, would be shut by
the steam rushing from the inlet P to R, like a back-pressure valve; the con-
sequence being that the pressure reducing apparatus would not open and close
at the identical degree of reduced pressure, but that continually recurring
fluctuations of pressure would be observable in the course of operation of the
apparatus. Indeed this is exactly what does happen in the apparatus of this class
as hitherto constructed.
The construction of a permanently relieved valve, characterized by the pro-
vision of the pressure relieving chamber such as R³ and a port such as y, is not
novel as such. Valves of this description, which were pressure free even in
their terminal position, have been employed before, but only as a single cut-off
device. For this purpose, however such a valve is unreliable, as it naturally
has to be enlarged in proportion to the full aperture of the steam-passage of the
reducing apparatus. In large valves of this description there is always the
serious drawback, that they do not close tightly enough, for the diameter of
the space or pressure reducing chamber must always be equal in diameter to
the passage in the main valve seat; and at the circumference of the small valve
where it slides in the pressure reducing chamber the want of tightness is also
correspondingly great; with the result that an objectionable increase of pres-
sure takes place behind the apparatus, notwithstanding the closed valve. More-
over in that case the power of the piston-which for practical reasons (i.e. on
account of the expansion) should be of small size,--is insufficient to secure the
valve firmly enough upon its seat.
In the reducing apparatus herein described, wherein the small valve 6 serves
only for the purpose of relieving the main valve-body from pressure, the dimen-
sions of the aperture of the pressure reducing chamber are so small, in com-
parison to the full aperture, that the lack of tightness referred to remains with-

page_text: out any material effect upon the reduced pressure. Besides, the valve b is so
Bmall, in proportion to the piston K, that it remains sufficiently tight even if a
minimum increase of pressure occur in the space R³.
Now it is true that the valve 6 might be constructed as a non-relieved valve,
making it so small however that it may only be affected to a minimum degree
by the drawback above mentioned; but in that case the large valve « could not
be relied upon to become relieved from pressure when required, as even though
the perforation were wanting, the leakages through the large valve (especially
after protracted use and from the consequent wear) would inevitably become
too great in proportion to the aperture II in the valve.
From the foregoing it will be seen that this invention consists of the com-
bination of an outer valve a, which, in its terminal position, is pressed down
upon its seat by the full difference of pressure, with a small valve b, arranged
to remain within and concentric with the said large or outer valve a, and being
consequently relieved from pressure even in its final position; the main valve,
however being relieved from pressure only by the opening movement of the
small valve; with the object of ensuring the ready opening and tight closing
of the valve-arrangement by means of a piston, such as K, made small in pro-
portion to the full sectional area of the aperture of the pressure-reducing appa-
ratus; and also for the purpose of reducing the fluctuations of pressure on the
delivery or outlet side to a minimum.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondents, I declare that what I claim is:-
1. In a pressure-reducer the combination of two co-axial valves, the outer
larger one of which is not relieved when closed, while the inner smaller valve
is permanently relieved for the purpose of attaining a great sensitiveness, this
valve being used for relieving the larger valve before pressure fluid is admitted,
substantially as set forth.
2. A pressure-reducer with two co-axial valves, the outer, larger one of which
is kept closed by the difference between the pressures existing at the inlet and
at the outlet; the main features of the arrangement being, that the inner,
smaller valve is relieved from pressure permanently, that is to say even when
in its terminal position, and so constructed, that after the unimpeded opening
of the said smaller valve by the counter-pressure (HK) the larger valve a is
first relieved from pressure and then also opened, substantially as hereinbefore
described and illustrated in the accompanying drawing.
3. In a pressure-reducer the combination with a chamber R communicating
by a port with the outlet and being without cover, of a regulating piston K
working therein up and down under the action of a load lever H. an outer larger
piston-like double seated valve arranged on same line as said piston K and
above it to work within a separate chamber communicating with the outlet, the
said valve a having a central opening through its length and a small port in
its bottom, an inner smaller double-seated valve working within said central
opening and within a relieving chamber R³ of equal diameter above and forming
a part of the larger valve the valve 6 having a channel y and being rigidly
connected with said piston K by means of a rod passing tightly through the
wall between chambers R and R³, substantially as shown and described.
Dated this 12th day of Dec………………
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.