IMPROVE- MENTS IN SAFETY VALVES
Year: 1873

page_text: LETTERS PATENT to George Allibon and Alexandre Manbré, of 19,
Salisbury Street, Adelphi, London, for the Invention of "IMPROVE-
MENTS IN SAFETY VALVES."
Scaled the 22nd May 1874, and dated the 29th November 1873.
PROVISIONAL SPECIFICATION left by the said George Allibon ana
Alexandre Manbré at the Office of the Commissioners of Patents,
with their Petition, on the 29th November 1873.
We, GEORGE ALLIBON and ALEXANDRE MANBRÉ, of 19, Salisbury
Street, Adelphi, London, do hereby declare the nature of the said In-
vention for "IMPROVEMENTS IN SAFETY VALVES," to be as follows:-
By this Invention instead of employing a piston or disc fitted and
working in one chamber, in combination with a valve fitted and working
in or on another chamber, so that the pressure acts on the under side of
the valve in the lower chamber, which is of greater area than the area of
the piston or disc in the upper chamber, upon which the pressure acts on
the the upper side, the pressure being communicated to both by means of
a connecting pipe, and the difference of areas between the valve and the

page_text: the pressure by a small dead load of weights pressing down the valve
and keeping it closed until the internal pressure in the boiler or other
vessel overcomes the weight and resistance to which the valve is loaded,
as is described in the Specification of a Patent granted to us on the 1st
day of January 1873, No. 2/73.
'
We by our present Invention apply and use or employ the differential
construction and arrangement of areas or acting surfaces in or between
the two valves; and we employ two valve seats within and on one
chamber, the fluid pressure acting between the upper face of the lower
valve and the lower face of the upper valve, or between the projections
or rings thereof or thereupon, or surrounding the body of the double
valve, whether the valve be a double valve with a solid shank or a
hollow bodied valve with two surfaces, in which latter case the steam,
when the valve has been raised or opened, is caused to pass from the
bottom seat through and up the centre or hollow body, and so to join
the general body of blow-off steam, which escapes from the top valve,
and thence into the blow-off pipe; whilst in using a double valve on a
solid stem or shank, that is to say, a valve having two discs, one larger
than the other, upon the same shank or stem (the upper one being the
larger one by say a square inch or more) the steam escaping from the
lower and smaller valve passes under it into a cross passage or delivery
chamber and into a pipe leading into the upper part of the breeches
pipe, and so into the blow-off pipe against the atmosphere only. In
each case the dead load or weight required is only that which is due to
the working pressure above which the valve is to open and discharge
the steam or other fluid multiplied by the difference between the
effective areas of the two valves, thus if the upper valve has two square
inches more of effective area than the lower valve and the internal
pressure at which the valve is to open is say 80 lbs. per sq. inch,
then a dead weight of say 160 lbs. only will be required to load the
valve.
For the purpose of giving relief to the valve and allow of the escape
of steam pressure a lifting screw and hand wheel may be employed for
lifting the solid shank valve. And for working the relief of and lifting

page_text: or pressure on the safety or blow-off valve be increased, nor the valve be
held down.
The dead weight or weights may be mounted on the screw spindle of
the lifting or relief gear below the valve, and between the breeches
pipes, and may form the hand wheel for turning the screw. Or the
weights may be mounted directly upon the valve, and the hand wheel
of the lifting gear and the gear itself may be fitted beneath the valve
and between the breeches pipes. Or the weights may be disposed in
various other ways as may be most convenient, but in the case of the
hollow bodied valve the load of weights may rest on the top of the valve
and be cast as rings so as to allow of the steam escaping from the bottom
seat to pass up the middle. Or the weights may surround the case or
shell of the hollow valve,
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Allibon and Alexandre Manbré in the
Great Seal Patent Office on the 29th May 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, GEORGE
ALLIBON and ALEXANDRE MANBRÉ, of 19, Salisbury Street, Adelphi,
London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of November, in the
year of our Lord One thousand eight hundred and seventy-three, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto us, the said George Allibon and Alexandre
Manbre, Her special licence that we, the said George Allibon and
Alexandre Manbré, our executors, administrators, and assigns, or such
others as we, the said George Allibon and Alexandre Manbre, our
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for “Iм-
PROVEMENTS IN SAFETY VALVES," upon the condition (amongst others) that
we, the said George Allibon and Alexandre Manbré, our executors or

page_text: administrators, by an instrument in writing under our, or their, or one
of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to
be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that we, the said George Allibon and Alexandre
Manbre, do hereby declare the nature of our said Invention; and in what
manner the same is to be performed, to be particularly described and
ascertained in and by the following statement and the accompanying
two Sheets of Drawings :-
By this Invention instead of employing a piston or disc fitted and
working in one chamber, in combination with a valve fitted and working
in or on another chamber, so that the pressure acts on the under side of
the valve in the lower chamber, which is of greater area than the area of
the piston or disc in the upper chamber, upon which the pressure acts on
the upper side, the pressure being communicated to both by means of a
connecting pipe, and the difference of areas between the valve and the
piston or disc being such as is compensated for or equivalated as against
the pressure by a small dead load of weights pressing down the valve
and keeping it closed until the internal pressure in the boiler or other
vessel overcomes the weight or resistance to which the valve is loaded
or compressed, as is described in the Specification of a Patent granted to
us on the 1st day of January 1873, No. 2/73.
We by our present Invention apply and use or employ the differential
construction and arrangement or disposition of two areas or acting
surfaces in, on, or between the two valves or on opposite sides thereof;
and we employ two valve seats within, or in and on one chamber or
casting forming one vessel or chamber, the fluid pressure acting either
between the upper face of the lower valve and the lower face of the
upper valve, or vice versa, or between the projections, faces, or rings
thereof or thereupon, or on annular projections therefrom or surrounding
the body of the double valve or conjoined valves, whether the valve be a
double valve or two valves with a solid shank or centre spindle, or it be
a hollow bodied valve with two annular faces or projecting surfaces, in
which latter case the steam, when the valve has been raised or opened
is caused to pass from the bottom seat through and up the centre or
hollow vertical opening and so to join the general body of blow-off

page_text: steam which escapes from the top valve and thence into the blow-off
pipe; whilst in using a double button or a composite valve with a solid
stem or a spindle shank, that is to say, a valve spindle or connecting
piece having two discs, one larger than the other, upon the same vertical.
shank or stem (the upper one being the larger one, or vice versâ by say
a square inch or more), the steam escaping from the lower (and in this.
case smaller valve) passes under it into a cross passage or delivery
chamber, and from thence joining the escape from the upper valve into
a pipe leading into the upper part of the breeches pipe or chamber, and
so into the blow-off pipe against the pressure of the atmosphere only.
Or the relative positions of the valves may be changed and the larger
valve be fitted within the lower part of the chamber or vessel and the
smaller valve be fitted on the seat in or on the upper part of the same
chamber, in which case the steam pressure is brought to bear the
under side of the lower area and the upper side of the upper valve, the
steam when escaping being then discharged between them and so
escaping into the blow-off pipe. In each case the dead load, weight, or
pressure forming the resistance required is only that which is due to the
working pressure, above which the valve is to open and discharge the
steam or other fluid multiplied by the difference between the effective
areas of the two valves, thus if the upper valve has two square inches
more of effective area than the lower valve and the internal pressure at
which the valve is to open is say 80 lbs. per square inch then a dead.
weight or other load or resistance of say 160 lbs. only will be required
to load the valve on whichever side of the valves the steam pressure is
applied.
upon
.
For the purpose of giving relief to the valves and allow of the escape
of steam pressure, either a lifting screw and hand wheel or a "tappet"
may be employed for lifting the solid shank valve. And for working
the relief of and lifting the hollow bodied double-seated valve (or either
description of valve) a "lifting tappet" may be employed, but by.
neither of these arrangements can the load or pressure on the safety or
blow-off valve be increased, nor the valve be held down, but it can be
lifted to a slight extent only.
Where screw lifting gear is employed the dead weight or weights may
be mounted on the screw spindle below the valve, and (or) between the
breeches pipes, and it (or they) may form the hand wheel for turning
the screw. Or the weights may be mounted directly upon the valve;

page_text: and the hand wheel of the lifting gear and the gear itself may be fitted
beneath the valve and between the breeches pipes. Or the load or
pressure necessary may be disposed in various other ways as may be
most convenient, but in the case of the hollow bodied valve the dead
load or the spring (in the case of marine boilers more particularly) may
rest on the top of the valve; and where weights are used they may be
cast as rings (or half rings) so as to allow of the steam escaping from
the bottom seat to pass up the centre or middle thereof. Or the
weights may be half rings and surround the case or shell of the hollow
valve.
For marine purposes more particularly a spring or springs may be
used instead of weights, and they may be disposed in any convenient
manner, and be of such a form and construction as not to increase in
their power or resistance upon the opening or rising of the valve or
valves from their respective seats within assigned limits.
In Sheets 1 and 2 we have shown some of the modes or methods of
constructing safety valves in accordance with our present Invention.
In Sheet 1 we have shown two modifications of the hollow bodied
differential valve, and of the modes of disposing of the dead load of
weights or the spring pressure upon the valve.
Figure 1 is a vertical section of a valve case which is formed in one
casting surmounted by the blow-off or steam discharge pipe, and having
two valve seats within the chamber or case, the lower one having the
smaller diameter and area (for the valve to rest upon), whilst the upper
one is of larger diameter and area for the upper valve (or its annular
surface or ring to rest upon), the valve being hollow; the steam, when
the valve is caused to rise escapes in part down into the small enclosed
chamber below and thence up through the hollow body of the valve
itself, whilst the steam escaping from or through the upper valve face
escapes into the blow-off pipe, where it is joined to or with the general
body of the escape steam. This valve may be cast in one, two, or more
pieces in its length or height, and be joined and secured together.
Figure 2 is a part section of Figure 1; Figure 3 is a double sectional
view (taken horizontally) of Figure 1; and Figure 4 is a sectional plan
of Figure 2.
Figure 5 is a vertical section of a modification, in which the (load of)
weights are formed of half rings and surround the body of the valve;

page_text: Figure 6 is a part sectional view of Figure 5; Figure 7 is a double plan
and section of Figure 5 taken horizontally; whilst Figure 8 is a sectional
plan of Figure 6.
In Sheet 2 Figure 1 is a vertical section of two annular valve faces of
different diameters cast together, and of the shape shown; the weight or
spring for loading the valve is here intended to be mounted on or above
the valve, although it may be suitably arranged or disposed otherwise,
and the shape or form of the composite valve may be varied so far as its
shank or spindle or the mode of connecting the two together is con-
cerned; and the larger area of valve disc may be below and the smaller
area above, in which case the steam pressure would be admitted above
and below, and the escape or discharge when the valve is open would
be between the two inner faces of the valve (or valves), and so be
discharged therefrom by means of a suitable opening or passage laterally
between them. Figure 2 is a corresponding view of Figure 1, Sheet 2;
Figure 3 is a sectional plan also of Figure 1, Sheet 2.
Figures.4, 5, 6, 7, and 8 show modifications in the form and arrange-
ment of the double disc valve or of the two valves as mounted upon a
common or on a composite spindle or shank.
In every case the upper and lower button or disc valves are of
different diameters (and areas), whether the larger valve be above or
below, and the passages for the admission and discharge of steam
respectively are correspondingly arranged to suit the same.
In every case it is desirable that the castings of the chamber and the
valve should be from the same metal and mixture of metals and be cast
at the same time to insure perfect equality of expansion.
Springs of various forms and constructions may be applied in sub-
stitution for dead weights, and for use on board of steam ships springs
are preferable.
Whenever springs are employed we first test them carefully at the
working temperature and properly adjust them; and when they are
applied to the safety valves we enclose them and secure them from being
tampered with.
Having now fully described and illustrated our Invention, we
claim,-

page_text: Figure 6 is a part sectional view of Figure 5; Figure 7 is a double plan
and section of Figure 5 taken horizontally; whilst Figure 8 is a sectional
plan of Figure 6.
:
In Sheet 2 Figure 1 is a vertical section of two annular valve faces of
3 different diameters cast together, and of the shape shown; the weight or
spring for loading the valve is here intended to be mounted on or above
the valve, although it may be suitably arranged or disposed otherwise,
and the shape or form of the composite valve may be varied so far as its
shank or spindle or the mode of connecting the two together is con-
cerned; and the larger area of valve disc may be below and the smaller
area above, in which case the steam pressure would be admitted above
and below, and the escape or discharge when the valve is open would
be between the two inner faces of the valve (or valves), and so be
discharged therefrom by means of a suitable opening or passage laterally
between them. Figure 2 is a corresponding view of Figure 1, Sheet 2;
Figure 3 is a sectional plan also of Figure 1, Sheet 2.
Figures, 4, 5, 6, 7, and 8 show modifications in the form and arrange-
ment of the double disc valve or of the two valves as mounted upon a
common or on a composite spindle or shank.
In every case the upper and lower button or disc valves are of
different diameters (and areas), whether the larger valve be above or
below, and the passages for the admission and discharge of steam
respectively are correspondingly arranged to suit the same.
In every case it is desirable that the castings of the chamber and the
6 valve should be from the same metal and mixture of metals and be cast
at the same time to insure perfect equality of expansion.
Springs of various forms and constructions may be applied in sub-
stitution for dead weights, and for use on board of steam ships springs
are preferable.
Whenever springs are employed we first test them carefully at the
working temperature and properly adjust them; and when they are
applied to the safety valves we enclose them and secure them from being
tampered with.
Having now fully described and illustrated our Invention, we
claim,―
Int The imma

page_text: 2nd. The arrangement and construction of hollow bodied double
valves, as herein described, fitted within or within and on a single casting
or hollow chamber, having two seats and also passages suitably arranged
for the admission and discharge of steam, as described and as illustrated
by the accompanying Drawings on Sheet 1.
3rd. The arrangement and construction of a single chamber or valve
box with two seats formed therein (or therein and thereon), and fitted
with two valves (disc or button shaped) combined either in one casting
or fitted and secured on one shank or connecting body or cast separately
and combined and fitted and secured together or mounted fitted on to
and secured to one another, as herein described and illustrated, to enable
them to be removed, refitted, and adjusted separately.
In witness whereof, I, Alexandre Manbré, have, on behalf of
George Allibon and myself, as joint Inventors, set my hand and
seal, this Twenty-eighth day of May, One thousand eight
hundred and seventy-four.
Witness,
WILLIAM HENRY SMITH,
19, Salisbury Street,
Strand,
London,
ALEXANDRE MANBRÉ. (L.S.)
W.C.,
Assistant to Mr. William Smith, C.E.