IMPROVEMENTS IN SAFETY VALVES OF STEAM BOILERS
Year: 1855

page_text: LETTERS PATENT to Peter Arrive, Engineer, of No. 7, Spencer Street,
Darnley Road, Gravesend, in the County of Kent, for the Invention of
σε
IMPROVEMENTS IN SAFETY VALVES OF STEAM BOILERS."
Sealed the 12th June 1855, and dated the 5th April 1855.
PROVISIONAL SPECIFICATION left by the said Peter Arrive at the
Office of the Commissioners of Patents, with his Petition, on the 5th
April 1855.
I, PETER ARRIVE, Engineer, of No. 7, Spencer Street, Darnley Road,
Gravesend, in the County of Kent, do hereby declare the nature of the In-
vention for "IMPROVEMENTS IN SAFETY VALVES OF STEAM BOILERS"
follows:-
It is well known that in the ordinary constructions of safety valves of steam
boilers the valves are very liable to adhere, and become fast with their seats.
Now, my Invention has for its object improvements whereby the consequences
of such liability of the valves to become fast are avoided; and, further, the
Invention consists of mounting safety valves on flexible discs fixed at their
outer edges, the valves being fixed to the central part of such discs. For these
purposes, in place of constructing the seat of a safety valve of one fixed ring
or surface, as heretofore, each seat is composed of several rings resting one on
the other, so that when pressed together by the valve, the extent of surface

page_text: contact of the rings will prevent the passage of steam between them. And it
is preferred that the several surfaces (where the parts of a safety valve seat are
capable of separating or parting) should be made of metal, or material not
readily capable of corroding, in order that they may not be liable to adhere one
to the other. Hence, when a safety valve is pressed on with an excess of pres-
sure, should the valve not part from the seat which is immediately in contact
with it, the next or the next ring of which the seat is composed will give way,
and the probability of all parts adhering will be rendered very remote. In
mounting safety valves when using flexible discs, the valve in each case is fixed
to the central part of the disc, and the disc is affixed at its circumference, so
that by the yielding of the part of the disc the valve will be enabled to rise
and fall.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Peter Arrive in the Great Seal Patent Office on the
5th October 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PETER
ARRIVE, Engineer, of No. 7, Spencer Street, Darnley Road, Gravesend, in the
County of Kent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of April, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Peter Arrive, Her special licence that I, the said Peter Arrive, my
executors, administrators, and assigns, or such others as I, the said Peter
Arrive, my 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 "IMPROVEMENTS IN
SAFETY VALVES OF STEAM BOILERS," upon the condition (amongst others) that
I, the said Peter Arrive, by an instrument in writing under my hand
and seal, 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.

page_text: NOW KNOW YE, that I, the said Peter Arrive, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof (that is to say) :-
My improvements relate, firstly, to improved. constructions of the common
safety valve; secondly, to an enlarged surface power safety valve for steam
boilers, which I denominate respectively, first, an annular ring pile steam
safety valve; second, an annular ring pile lift steam safety valve; third, a
flexible disc power steam safety valve.
The two first of these patented improvements apply indefeasible certainty
of action to the original and earliest steam valve in general use, commonly
designated the steam safety valve. By these improvements the common valve
is seated upon a pile of annular incorrodible rings. Such being additional
to its original construction, it may with its ordinary lid be wholly retained,
without alteration, intact, and without doubt of its protective utility. These
rings consist preferably of sterling sheet silver, metal, or other, electro-plated.
With one annular ring resting upon these incorrodible rings, which become
detached when the ordinary lid fastens down or into its seat, it will become up-
lifted so combined, and thereafter serve alike to all intents and purposes to
pass away collective steam, that passing away between it and one or the next
or next other of those rings as freely as before from between the lid with its
proper seating. This pile of separable rings so applied to the common valve
represents multiplication of valves, excepting their united capacity, for each
ring virtually constitutes the next, and the next its parting and successor,
independent of that which receives and seats the valve lid.
This improved arrangement of the common valve, then, closely allied in
appearance, and alike occupying the same proportions, applies with all its uses,
and may replace that valve, bolt hole for bolt hole, upon locomotive, marine,
and stationary boilers. Under this arrangement the stem of the valve lid,
passing through the cross bar of the marginal annular ring, cannot retain
the lid down into its seat, from its own fixation being passive along with it.
The configuration of this ring has provision that during the ordinary escape
of steam, as well otherwise, the whole pile of separable rings shall have no
tendency whatever to be uplifted from off their seats, the contained pressure
from steam acting downwards to depress them from around the interior margin
of the ring, that being preferably from one quarter to half an inch lesser
diamater than the interior diameter of the valve lid. The diminished space
which remains is more than amply sufficient to satisfy the conditions of safety
essentially whilst the valve does not become of some diameter less than three

page_text: inches, touching which it is concluded that because the lid rarely attains to
th of an inch rise above the plane of its seat, the area not only greatest but
most effective will continuously be that of the thorofare space left.
The following general observations concerning loading of these valves are
held of prime necessity advantageously to employ these improvements. It is
required the application of load or weight applied to the lid of the valve shall
be incapable either to overload or fasten it down; therefore, when the direct
action of dead weight is applied, and that becomes ponderous, such may be
collective, from several senicircular plates of cast iron, each of about two inches
thickness, mounted one upon another, crossing joints supported upon one
circular plate, the whole suspended by one bolt hooked through the eye
carried by the socket, which is cottered to the lowermost end of stem of valve
lid, thence hung vertically under the centre of the valve, being contained in the
steam space under the dome of the boiler. This mode of suspension, which is
every way the simplest, admits neither of increase or access, whilst it continues
an unchanging vertical weight, shewn by the Drawing, Figure 1.
Direct weight applied from above the lid downwards upon the valve,
requires oftentimes more attention to its adjustment than is bestowed upon it,
seeing that abundant oxidization from the substance of iron may occur here,
and that the load must gravitate, balanced exactly to move freely, placed upon
the axis of the valve; and because the quantity of gross weight equal to the
resistance required may be great, its equivalent may preferably be derived from
substitution of the compressed resistance of one metallic spring helix or other,
shewn by the Drawing, Figures 4 and 5.
sure.
Pressure upon the valve communicated from leverage requires alike more
attention to its manner of action than often is bestowed upon it, seeing very
minute accuracy of motion is required to act freely with it under great pres-
The relation which the point of fulcrum of lever bears with the point
of suspension and axis of the valve has therefore been shewn, Figure 4, their
relative positions being too generally neglected. Thus, a horizontal right line
projected from the point of bearing of the fulcrum end of lever, which is
always somewhere above the valve, is that line upon which the points of action
and suspension of the pins which attach the said lever and the valve meet in
extension of the same horizontal right line, and which is the axis both of
motion and of pressure; any deviation thence has more or less tendency to
lock or jamb the valve against rising. The weight required to load a valve
three and a half inches diameter with fifty pounds upon each square inch is
four hundred and sixty-one pounds, wherefore the mode of applying such well
becomes the most careful consideration.

page_text: .Inasmuch as surfaces rendered incorrodible from being electro-plated will
prevent adherence from galvanic corrosion, the under side of marginal annular
ring and upper side of rim of valve box may advantageously be electro-
plated. Sheet copper or brass, quite flat, of the thinnest gunges, being cut
or punched, flat rings, subsequently electro-plated, are capable of the service of
wholly silver ones. The common safety valve seated conically, as exhibited
under these improvements, laid upon the marginal annular ring and pile of
incorrodible rings under marginal steam pressure, is shewn by the Drawing,
Figures 1 and 2.
My improvements further include an extension of the ordinary means of
steam escape whenever in excess, derived from uplifting at least one of the
scats; to effect which I apply thereto two lugs cast therewith, so as they pro-
ject from outside of the body of the lowermost annular ring, which serves to
attach it, through the intervention of screwed pins and nuts, to the cross head or
bow which rides across over the valve lid, whereby it becomes capable of any
degree of regulation from set of the lock of the nuts, as is shewn by the Draw-
ings, Figures 3 and 4, wherefrom at the least another outlet for accumulativo
steam becomes provided, any increasing pressure or quality of which may
thereby be set free, independent of the action of the piled rings, which present
outlets only in case of adhesion of the valve lid with its seating. This arrange-
ment provides to uplift the annular seating next under the marginal annular
ring from off its seat or proper bearing, and such effect is obtained from the
force of the ascending action of the lid of the valve under pressure of steam.
Of this manner two modes are shewn; the first, Figure 3, which does not
attain action until the valve lid has risen, so as to reach and touch the pen
under the bow of the cross head above it, when, if continued, it commences to
raise the cross head, stem, annular ring, &c. together. The second, Figure 4,
does not uplift the seat for thorofare of steam until the lid has uplifted,.
through the medium of the metallic spring, the lever arm above along with it,
or such other resistance as may be possible to be applied by means of external
access, none from externally being capable of reaching the lid to hold it down
from rising. Thus the action of this valve arrangement in either instance is,
it is capable to attain two lifts, each proving outlets for steam. The first
upraises the lid from off its seating, Figure 3, a, to touch the pin of the bow d;
any continuation of movement thereof lifts the annular ring seating b from
off c, attaining to the second lift. This lid always allows first the steam to
escape from a, its proper seat. It cannot be held down from above, neither
at a or b. Any number of annular seating incorrodible flat rings may be
interposited at further to promote safety by partings.

page_text: In the second instance, Figure 4, the seating c being considered of as the
common outlet or working valve, should the pressure thereupon from lever
exceed that of spring pressure upon the lid, the lid will rise first from off a;
should the spring pressure exceed the lever pressure, then 6 will rise from off c
first. With internal weighted arrangement the valve, Figure 3, is shewn pro-
vided with stem, having screw turn handle wherewith to raise the valve from
being externally under command at pleasure. The valve lid a, Figure 4,
cannot be pressed upon at all by the lever; the pressure of the spring alone
affects it, to which neither control or access may ordinarily be had from the
outside by any contrivance whatever.
Should weight be removed or lightened sufficiently from off the lever arm,
the contained steam pressure in excess raises the ring 6, with all above it, off c,
its seating; thus, should the spring be compressed down upon the lid of the
valve to fifty-five pounds (square inch area), and lever to fifty pounds, from
weight upon the seating 6, the lever will rise first, the counteracting steam
pressure under the lid lifting thereby the annular seating ring 6 from off c,
the seat of pressure properly of the lever. If spring to fifty pounds lever to
fifty-five pounds, the lid will act at a, its seat first; should steam exceed fifty-
five pounds, then both act rising together, then both thorofares blow off steam
together.
The next improvement applies indefeasible power with indefeasible certainty
of action to steam safety valves from the flexible disc, whose effect is derived
from surface moved and yielding space obtained from central movement of
flexible sheet metal under steam pressure, or which usefully applies the pro-
perties of such flexile body when suspended to curve, move, or deflect to the
practical purposes which constitute this the flexible disc power steam safety
valve. This patented arrangement comprehensively carries out both fully
and perfectly the principle that the inherent force of steam, accumulated
upon the greater surface, enlarged against the lesser surface, will lift the
cover of any such, applied as the lid of any steam safety valve. The flexible
disc possesses the greater surface, and, coincident, importantly the greater
power of action, because it must be admitted the exercise of its full power
remains free, having no drawback from friction from contiguous parts that
might arrest some of the power of its motion as a first mover, a rare exception
in mechanics.
The constructive proportions of the flexible disc need not exceed the fol-
lowing as a general rule:-Taking the area in square inches of the diameter
under the lid, which, presented to steam, is ordinarily termed the diameter of the
safety valve, multiplied twelve times, and divided by 0-7854, gives a number

page_text: the square root of which assigns the interior diameter of the disc; or number
of square inches area of common valve, multiplied by number times increased,
and divided by 0.7854, gives a number the square root of which assigns the
interior diameter of the disc. The diameter so obtained must beyond that be
extended sufficiently for support and covering down to be maintained steam-
tight upon the flanged rim of the retaining valve box, wherein it will then be
enclosed wholly, and the flanges thereof will grip and carry it flatly laid over
the valvular opening. To this disc the valve lid may be connected in the
manner shewn in any case by the Drawing, Figure 5.
The plate or sheets employed may be sheet brass or iron; but there exists
certain modifications which concern the nature or quality of the metal employed,
independent of the strength, &c. Thus, when mercury, which may overspread
the disc, is employed so to do, iron wholly must enclose the mercury, never-
theless iron and brass together may be enclosed under the same cover, iron in
contact with mercury, brass next against steam, moisture being excluded from
between any two plates always under the arrangement provided.. Of flexible
sheet, the thickness increases by the number of plates one-sixteenth of an
inch thick each; as from one-sixteenth to three-sixteenths of an inch thick
is composed of one, two, or three plates. The least, or one-sixteenth of an
inch thickness, may be considered sufficient up to twelve inches diameter, with
fifty pounds upon each square inch.
Difference of expansion of the flexile metallic sheets proves of no moment
here, each being free to curve or deflect from any recognised flatness of posi-
tion, because each, independent of the other, will occupy some determinate
quantity of space irrespective of the other, or may be dissimilar. So far as
concerns curvature, the brass plate externally will have freest range next the
steam.
The flanges of the valve box which support and include the rim of the disc
are, for rendering that perfectly steam-tight, preferably to have rings or strips
laid, as rings of vulcanized india-rubber, around the rini, one inside the other,
outside the bolts; such may be three-eighths of an inch broad uncompressed.
Calking of cast-iron cement else may be employed preferably to close the
edges of the joints against insinuation of mercury or steam, as shewn by the
dotted sections of the Drawing, Figure 6, or when required, to prevent access
pro tempore to the bonnets of lock-up safety valves. Besides the foregoing,
this arrangement of the flexible disc provides overspreading its surface within
with comparatively but a small quantity of fluid mercury, to maintain resist-
ance against steam good under densest pressure. This capability is derived
from superincumbent pressure from column of mercury of smallest diameter.

page_text: This mercury, closely contained within iron, remains wholly incapable of
deterioration, either from oxidisation or from admixture, unlike in ordinary
steam guages, this being wholly inaccessible to steam and water and open air
impurities.
The manner of steam escape from the flexible disc power valve is, from the
usual manner, the reverse, the steam entering from outside the annular opening
introducing itself between the separated surfaces, and so into the throat of the
escape pipe, therefrom passing away. Upon that condition the disc is moved
or floated by immensely greater force than can be brought to effect separation
of the bearing surfaces of the common valve within other equal thorofare.
The load of pressure laid upon the disc may operate applied from leverage
in the usual manner, but most compactly applied is from the compressed
resistance of one centrically pointed helix or cylindrical steel spring, shewn by
the Drawing, Figure 5, or from mercury column, Figure 6. The vertical
section of this spring is commonly the parallelogram of a more or less
flattened bar; preferably of cast steel. Its length and stiffness being deter-
mined, its ends are each "jumped" to a swell to receive the plug ends of
the steel centres, provided as shewn by the Drawing, Figure 5. Whilst being
coiled, each turn may be kept asunder from the next by interposing a rod of
nail iron between them, whilst winding around the mandril. Each end is bent
inwards, lastly, to centralise the action of the several coils.
Whenever the helix of steel spring, which is more or less corrodible, unless
electro-plated or otherwise protected, is required to be substituted, upon that
account I prefer to employ the combined brass hammered metal spring g,
Figure 4, partly dotted in red, instead, which may be produced from casting
in tough brass, the form of the letter U, hammering the ends thereof, and
employing them united as the oval spring shewn, Figure 4.
With mercury arrangements, shown by the Drawing, Figure 6, the pressure
is determined from height to which the wrought-iron tube three-eighths of an
inch bore, having five-eighths of an inch diameter, is carried. This tube for
support may be enclosed within another three-fourths of an inch bore, having
one inch diameter, capable to rise as high as the receiver of cast iron. The
packing sole leather is compressed under the collar of the internal tube, which
is welded, that is, screwed down with the collar screw, which may be brased
upon the lowermost end of external tube. The upwards end of mercury tube
terminates half way in the iron packing box which is above it, and towards
which the lowermost end of the upper tube descends nearly to meet it.
For maintaining the position of the annular ring seating with conical lid,
the disc, applied as shewn by the Drawing, Figure 5, the usual provision of
о

page_text: three or four several pins circumscribing the said rings, is preferably applied.
The same applies to centralise the position of the annular ring with common
valve lid, shewn by the Drawing, Figure 1. Whenever the common valve
lid be attached to the flexible disc, as in the manner shewn by the Drawing,
Figure 5, it should underneath the cover be provided with a solid square, cast
with the metal, to hold it fast whilst fixing to the disc.
Having thus described particularly and ascertained the nature of my Inven-
tion, and in what manner the same is to be performed, I desire it to be under-
stood that I claim as secured under the said Letters Patent,-
Firstly, the pile seating of rings, being the marginal annular rings which
seat the valve lid, preferably having conformation to become compressed under
steam upon the annular margin of top of valve box; the said pile, excepting
the upper marginal ring, which may or not be electro-plated, being pre-
ferably flat rings of sterling silver sheet, or of metal electro-plated with silver,
so as to become incorrodible.
Secondly, the lifting apparatus in connection, worked by the ascent of the
valve lid attached to the seats, uplifting one or more either along with the
valve lid or subsequently to its rise, so as the action of rising of the seat or
seats shall open the second thorofare or outlet for steam.
Thirdly, the flexible disc, being the sheet or plate or plates of flexible metal,
preferably composed of brass or necessarily of iron, which covers the annular
opening when directly laid thereupon as the covering lid, or intermediately be
employed to communicate movement to the lid when attached to it, and, as in
the former instance, encloses fluid mercury whensoever applied, as herein-before
mentioned, to cover the annular opening, or to give movement to the safety
valve of steam engines.
In witness whereof, I, the said Peter Arrive, have hereunto set my hand
and seal, this Fifth day of October, in the year of our Lord One
thousand eight hundred and fifty-five.
Witness,
ROBERT TAPLIN.
PETER ARRIVE. (L.S.)