IMPROVEMENTS IN SAFETY VALVES
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Alexander Orme at the Office of the
Commissioners of Patents on the 30th October 1877.
ALEXANDER ORME, of No. 91, Caledonian Road, in the County of Middlesex,
Engineer. "IMPROVEMENTS IN SAFETY VALVES."
This Invention has for its objects improvements in the construction of safety
valves for steam boilers for the purpose of relieving the boiler of any excessive:
pressure of steam above that which it is designed to carry, or to which the valve is
set, and for graduating the pressure of steam in the boiler and increasing and.
decreasing the area of the escape passage by means of adjustable arrangements.
My Invention consists of the means employed in holding the valve upon its seat.
against the pressure of steam in the boiler, and in the method of applying the
pressure of the spring to the valve, and of compressing the spring itself, and in
providing the outer surface of the valve seat, or valve, both or either, with an
adjustable ring, and providing the ring with an angular face corresponding to a like
angular face on the valve or valve seat or the rings, where more than one are used,
with corresponding angular faces, and of the several methods employed in adjusting
the ring or rings and holding it or them in position when adjusted, and in the axial
arrangement and other means of centralising the valve and its action, and providing
the upper and lower parts of it with a slieve or bearing, and preventing the leakage
of steam into the spring chamber, and also in the arrangement of the parts employed.
in locking the outer cases to or on to the base, where required, so as to prevent the
valve from being tampered with; and of the combination of all or any of these
several parts according to requirement.
Figs. 1 and 2 of the accompanying Drawings represent vertical central sections of
a safety valve showing part of my said Invention. Fig. 3 represents an elevation
of the same, a portion of the outer cases being broken away, showing a portion of
the operating parts, and Fig. 4 represents one half of a vertical central section.
In Figs. 1, 2, 3, and 4 A. represents the base of valve which may be attached
to the boiler in any known manner; B is the outer case enclosing the operating
parts; and Fig. 3, which is of the same internal construction as Fig. 1, is provided
at its lower end with an outward projecting flange a, fitted to rest on a like flange.
a¹ on the base A, and is firmly held thereon by screw bolts. 6 (one of which is

page_text: shewn), passing through the said flange a into flange a¹, as shewn in Fig. 3. The
base A is provided at its centre with an annular opening C, which is shewn in Figs.
1, 2, and 4, which communicates with the interior of the boiler (not shewn); D is an
annular bushing which is tightly fitted within the opening C, and is shewn in
Figs. 1 and 4 only, and extends upwards above base, and is screw-threaded at its
upper end externally when so required, as shewn in the same Figs.; E is an
adjustable ring fitted upon the threaded portion of the bushing D, as shewn in Figs.
1, 2, and 4, and so arranged as to admit of being turned on the said bushing, the
object of which is to allow the ring to be raised or lowered as may be desired. The
upper edge of the ring is chamfered on its inner side, forming an angular face d, the
latter extending downward to the end of the bushing; or a similar adjustable ring
may be similarly fitted to the valve itself.
The seats and faces may be flat, curved, or bevelled. One object of the said
adjustable ring or rings is to regulate and restrict the amount of pressure between
the valve seats, and also the area of the escape passage; and another object of
this arrangement is to allow one spring to have greater range and variation of
pressures. The said adjustable ring or rings also enable the degree of compression
on the spring to be regulated while in action. F is the valve, having a central
hub, and provided on its lower surface with radial wings e, adjusted to fit the bore
of the bushing in the usual manner, as shewn in Figs. 1, 2, and 4. The diameter
of the upper portion of this valve exceeds the diameter of the wings, forming an
annular horizontal face f, adjusted to bear on the upper end of the bushing, shewn
in Figs. 1 and 4. The valve is bevelled on its outer side, forming an angular
face d', the plane of which is parallel with the plane of the angular face d on the
ring. G, G, are vertical studs, which are permanently secured within the base A,
as shewn in Fig. 1; H is a cross head mounted on the upper ends of the studs,
and secured in a fixed position thereon by screw nuts g, g, g, g, arranged upon the
respective studs above and below the cross head; I is a primary spindle, which
passes loosely through an opening formed centrally through the cross head, and-
extending downwards to a point immediately over the valve, as shewn in Figs. 1,
2, and 4, and loosely into the cap R, as shewn in Fig. 2, and through the washer S
and screw cap or nut V, as shewn in Fig. 4, and is provided at its lower end with
an annular flange n formed thereon; K is a spiral spring, which is loosely fitted
upon and around the primary spindle between flange n and the cross head, as
shewn in Fig. 1. The primary spindle is made hollow, as shewn in Figs. 1, 2,
and 4, the said hollow or cavity converging at its upper end to a common centre,
as shewn at K¹, and extending upwards to a point, which may be optionally
near to, at, or beyond the end of the spring. Ĺ is the valve spindle, which is
loosely fitted within the cavity of the primary spindle, and is made pointed at its
ends, as shewn at o, o. The upper point of this spindle fits into the converging
point in the primary spindle, and the lower point of the spindle into a like cavity
formed concentrically within, and extending downward nearly to the bottom of the
valve, as shewn in Figs. 1, 2, and 4.
The primary spindle and lower end of valve may be constructed as shewn in
Fig. 4 by inserting a screw-threaded bolt 6 and 6¹ correspondingly centred in the
end of the primary spindle I and lower end of valve F. The object of loosely
fitting the primary spindle within the opening in the cross head cap, washer, and
nut, and of loosely fitting the valve spindle within the primary spindle and cavity
in the valve, as described, is to admit of free radial movement of the valve
spindle and primary spindle, and thereby prevent any unequal pressure of the
spring upon the valve, which might otherwise be produced by any improper
adjustment of the cross head or inequality of the spring. M is a horizontal
fulcrumed lever passing through a mortice formed in the outer case or cases, as
shewn in Figs. 3 and 4, and may be varied in position, as thereby appears, and is
fitted to admit of a free tilting movement. This lever is fork-shaped at its inner
end, and passes into a groove i formed around the primary spindle near its upper
end, as shewn in Fig. 3, the object of which is to relieve the valve from the

page_text: pressure of the spring, and thereby allow the valve to lift from its seat when the
pressure-of steam in the boiler is below the pressure which the spring is adjusted
to carry.
:
In Fig. 4 the lever is applied to the lower end of the primary spindle with the
same object as explained in Fig. 3. N is an annular concaved plate, which is
attached to cross bars n' extending centrally below the opening in the neck, as
shewn in Fig. 3. The area of this plate exceeds the area of the opening in the
neck, and is located so as to form an annular space n", through which the steam
escapes. This plate forms a guard which will prevent the valve from being
tampered with at that point.
D', Fig. 3, is a ring loosely fitted upon and around the base of the case B, and
arranged to rest upon the flange a of the same. This ring is provided at its upper
edge with an inwardly projecting flange e arranged to fit loosely around the wall
of the case, and which flange is provided with notches arranged opposite to each
I other (not shewn). The case. B is provided on its outer surface with lugs ell, ell,
arranged opposite to each other, and of the proper size to pass loosely through the
notches in the flange of the ring, and which are located on the case B at the proper
distance from the bottom thereof to admit of the ring being turned round between
them and the flange a of the case. The ring D' is also provided at its lower edge.
with an outwardly projecting lug p corresponding with a like outwardly projecting
lug pl on the flange a of the case, which are each provided with an opening formed
through them to receive the ring of an ordinary padlock, by means of which the.
ring can be locked so as to prevent it being removed or displaced.
The arrangement of the ring D¹, Fig. 3, is such as to wholly surround and cover
the bolts uniting the case B to the base, and the notches are so arranged relatively
to the position of the lug p, that when adjusting the ring upon the case and
in position to admit the passing of the padlock ring through the openings, the ring
must be placed in proper position on the case to allow the lugs ell, ell, to pass
through the notches in the flange. The ring is then dropt down so as to rest
upon the flange a, when it is turned partly round to bring the openings in the
lugs p and p in the same plane, thereby causing the flange on the ring to pass
under the lugs ell, ell, thus protecting the bolts from being unscrewed and the
valve from being tampered with. Loosely mounted upon and around ring E is a
supplemental ring E¹ of suitable metal adjusted to turn thereon and bolted to-
gether at its ends, forming an outward projecting lug t, as shewn in. Fig. 1.
The ring E is provided at its base with an outwardly projecting flange m³,"
within which are formed a series of notches (not shewn), which notches are each
adapted to alternately receive a depending lug on the lower edge of the
supplemental ring E', by which the two rings are locked together so that neither
of them can turn independently of the other. The ring. E is also provided with
slots x, x, the object of which is to allow the adjustable ring E to be clamped or
held in a fixed position by the supplemental ring E¹.
The adjustable ring E, Fig. 2, is screw threaded on its inner side to fit a corre-
sponding thread on the base A, and is provided with lugs t, t, which are shewn,
and which are set apart, and have a corresponding slot in the adjustable ring E.
The lugs are provided with holes, through which a screw bolt is passed to draw.
them closer together, by which means the adjustable ring E is clamped on the
base A, and held in position thereby; or the adjustable ring E may be held in
position by a lock, nut, or set screw (not shewn)...
The adjustable ring is also screw threaded on its upper and outer edge. The
yoke B, Fig. 2, has arms b, b, connecting the cap H' with the ring H. The cap H¹
is provided with a slieve D at its upper end through which the stud E of
cap R passes, and the ring His screw threaded on its inner surface to correspond
with the external screw thread on ring E. The outer side of the ring H is
provided with arms B¹, B¹, by means of which the yoke B may be turned round
on the ring E, the object of which is to admit of the pressure of the spring being
adjusted. The primary spindle I is provided with depending lugs p, p, Fig. 2,
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page_text: which fit loosely into corresponding openings p¹, p¹, in the top of the valve F, the
object being to prevent the primary spindle from turning round on the points o, o,
while adjusting the spring.
The
The bushing D, Fig. 4, is provided at its lower end with radial arms w, support-
ing a hub which serves as a guide for the lower part of the valve slieve x.
valve F is provided on its upper side with a slieve x¹ which is fitted into a
bushing P, and which bushing is fitted into the lower end of the spring case G, and
serves as a guide for the valve, and by means of which the communication is cut
off between the spring chamber and escape passage, thereby preventing any steam
from being admitted to the spring chamber. The bushing P may be provided with
grooves P1, P1, the object of which is to serve as a packing the more effectually to
obstruct the passage of the steam. The adjustable ring E, Fig. 4, is provided on its
outer side with teeth to which the pinion F¹ is geared. The pinion spindle F¹¹ is
provided with bearings, the upper bearing being in the flange Y of the case G; this
pinion spindle projects above the flange Y, and it may be squared or otherwise so
as to admit of the pinion being turned round from the upper side of the flange Y,
thereby raising or lowering the adjustable ring E and admitting of it being
adjusted when under steam pressure or otherwise, the object of which has been
already explained.
The base A is provided on its upper side with an inward projecting flange to
which the base of the spring casing G is fitted, by which means all its parts are
kept perfectly concentric and held in position by screw bolts (not shown). The
case G is threaded internally at its upper end, and has a featherway cut vertically
through its threading, into which the feather S¹ of the washer S is loosely fitted so
as to prevent the spring K and the primary spindle I from being turned upon the
points o, o, while adjusting the pressure of the spring by the cap V. The screw
cap V is provided on its upper end with means by which it may be turned round
for adjusting the pressure of the spring. It is also screw threaded at its upper end
into which the screw bolt H is screwed, the object of the bolt H being to hold the
case B in position.
The casing B serves as a protection and prevents the valve and its arrangements
being tampered with when locked up. The casing B is provided at its upper end
with a chamber m, and a hole m³, through which the bolt H is passed and secured
into cap V. The upper chamber m is provided with slots m" passing through the
outer walls, through which the gib pin b is passed and is locked in the usual
manner. The spring casing is provided with two or more slots, and a slot for the
introduction of the lever M. The casing B is also provided with slots as shewn
at n¹, placed between the slots and spring case G, the object of which is to allow
free circulation in and around the cases, and the escape of any vapour that may
have passed into the cases. The casing B is also provided with a slot through 4
which the arm of the lever M passes. The lever M is so fulcrumed as to prevent
it being moved in or out, and fits into a recess in the flange Y which keeps
it from being moved horizontally or interfering with the proper action of the
valve.
For the purpose of testing the boiler by hydrostatic pressure or otherwise with- 4
out disturbing the adjustment of the spring, the valve may be loaded by means
of the screw bolt H, which may be accomplished by unlocking the valve and
removing the case B, and screwing the bolt H down upon the bolt b¹. T'his
arrangement prevents the possibility of the valve being left loaded when again
locked up.
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