Improvements in Safety Valves.
Year: 1895

page_text: Date of Application, 7th May, 1895-Accepted, 7th Sept.,
1895
Ohio, U.S.A, Manufactures.]
Improvements in Safety Valves.
I, REGINALD WALTER BARKER, of Monument Chambers, King William
Street, London, E.C., Patent Agent, do hereby declare the nature of my said
invention and in what manner the same is to be performed, to be particularly
descubed and ascertained in and by the following statement:-
My invention relates to safety and rolief valves and particularly to that class
known as automatic safety valves.
The object is to provide a valve that will be thrown wide open so as to provide
a free dischargo the full area of an unobstructed pipe of the diameter of the
valve the ustant the pressure with which the valve is set 18 reached, and be as
quickly closed when the pressure is reduced. To this end it consists in providing
what I term a trigger valve and balance chamber in connection with the main
valve, whereby a much smalle valve and much lighter spring may be employed
to accomplish the results aimed at, and partially attained by the larger valve now
in common use, all of which will be fully understood from the following description
of the accompanying drawings illustrating the preferred form of my invention,
and the two modifications of the same adapting the safety valve for use as a
cylinder relief valve; my invention being particularly intended for use as an
automatic safety valve.
The modifications illustrate its use in other positions.
Referring to the drawings, in which like paits are indicated by similar reference
letters wherever they occur throughout the different views:-
Fig 1 is a longitudinal central sectional view of my preferred form of valve for
use as an automatic safety valve for a steam boiler.
Fig. 2 is a modihed form of the saine, which may be used for the same purpose,
but is more especially adapted for a relief valve
Fig. 3 is another modification, in which the trigger or setting valve 18 placed
alongside of, instead of in, the same axial plane as the main valve; and
Fig is a top cross sectional view taken on the line -z of Fig. 1
Referring hrst to Fig. 1, A is the main case of the valve, provided with induction
port or branch a for attachment to a steam boiler, and an eduction branch a¹ to be
connected to a pipe leading to the open air, or to a waste or bilge pipe, to carry
the steam discharged outside of the boiler room. The case A is covered by a
cap A', which has a screw threaded neck to enter the screw threaded portion of
the valve chamber proper, and A', an upwardly extending tubular portion of said
cap A', which forms the spring chamber, the parts A, A' and A³, forming the
valve case proper. The cap A' has a downwardly depending branch a', terminating
in a chamber of enlarged diameter a. The upper tubular portion A bas a
partition a, which is centrally perforated to furnish a seat for the relief valve C,
and oufices a lead vertically through the wall of the casing or shell a²; the said
partition a having a small chambei, or having adial openings to form a com-
munication between said vertical orifices, and the cential cone shaped opening
which forms the valve seat in the partition a
The main valve D consists of a hollow shell with a depending tubular neck d,
having laterally projecting wings or guides d, to snugly fit within the reduced

page_text: portion of the case shell A; the contact surfaces being the bevelled lower edges of
the valve which meet the interior bevelled surface of the valve case A, and the
cap d', which is screwed on to the upper end of the said valve; the said cap and
the outer projecting portions of the valve fitting snugly within the lower part of
the shell a, of the said main valve.
№18 a metal packing ring interposed between the cap d³, which is adjustable
against the said ugs, and the upper flange of the valve D to prevent the escape of
steam from the chamber D'; packing rings d' also surrounding the said ring d to
break joints and make a closer fit.
There is a free opening from the branch a, between the tubular neck d of the
main valve and the tubular part a*, which depends below the trigger valve and is
secured to the cap A' and runs freely through the tubular neck d of the valve D,
to allow a free access of steam, from the boiler into the chamber D'
The upper
surface of the valve D inside of the chamber a', being of greater area than the
under exposed surface of said valve, the pressure of steam will hold the valve to its
seat until the pressure in the chamber D is relieved.
The trigger valve and the relief valve C, are both held to their seats by the
pressure of a spring E, which is compressed between an outwardly projecting
Bauge on the valve C, and the top of the tubular cap ", which is adapted to screw
within the tubular stem A' of the valve case. Within the tubular stem c¹ is the
1od, which is coupled to the tubular stem by a piu passing through both of
them. The lower end of this rod extends below the relief valve C, and cuters a
perforation in, and above the stem, of the trigger valve b, so that the trigger
valve and relief valve are practically coupled to move together. The stem &¹ of
the trigger valve passes loosely through the downward extension a², to guide the
action of the said valve, which, when open, permits the passage of steam into the
chamber C'.
The upper part of the portion A' of the valve casing has an annular flange or
disk a at its upper end, which has a series of perforations to receive the pointed
end of the regulating screw, which projects down from a cap or head F, which
has a downward tubular extension thi caded to screw into the upper portion A',
of the cap A' to bear upon and regulate the tension of the spring E, to set the
valve to any desired pressure. To accomplish this, the screw is backed out, the
tube forced down by screwing the head down into the part A, until the spring
has received the tension required, when the screw is screwed back into one of the
perforations in the disk a", which prevents the crown head from turning and fixes
the tension of the spring. The regulating screw fis adjustable through one arm
of the head F, and its head is encased in a tubular extension 1. On the opposite
side of the said head are upwardly projecting lugs /, between which is fulcrummed
a lever, the shorter aim of which is bifurcated to pass on each side of the relief
valve stem o and c, the upper end of the stem being provided with a nut or
colla C³.
An angle gauge I, threaded at its lower end, screws into the tubular
extension, and supports a gauge screw at the pait J, which screw is adapted
to limit the movement of the opening by being adjusted above the ends of the
stem e. c. By this means the relief valve may be lifted by hand at any time it is
desued to test the valves or see whether they are free to move from then seats.
The cap A is provided with an annulur key seat a', by which the parts are
secured firmly together.
The operation of the device in use is as follows.-The valve being applied to a
steam boiler, the tension of the spring E is adjusted to open the trigger valve b, at
any pressure desired. This can be determined by the engineer by adjusting the valve
to let go or open at any pressure indicated by the steam gauge, when the screw fis
turned down into any one of the perforations in the disk a It will be seen that
the pressure of the steam will hold the main valve to its seat unaided by any sping
so long as the trigger valve keeps its seat The underside of this valve having
"but a small aica, a very light spring will hold it to its seat under a heavy pressnro

page_text: of steam in the boiler, but the instant it leaves its seat, it will force up the relief
valve C, relieve the pressure from the chamber D', and therefore, from the main
valve, the pressure from the chamber D', passing from the annular chamber or
tubes a, through the perforations to the relief valve seat and out through the
perforations a, in the shell a', to the open air. The stant the pressure in the
boiler is reduced below the tension of the sping E, the trigger valve will again
close and the pressure of the steam in the chamber D' instantly force the main
valve to its seat.
It will be seen that my valvo is easily constructed, requires but little fitting, and
is readily put together for use; and that, owing to its auxiliary or trigger valve
being of small aiea, aud the steam having access to both sides of the inain valve.
to hold the said valve to its scat until the trigger valve is released, which, when'
eleased throws the full pressure of the steam under the main valve, thereby
rapidly opening it, that the discharge 18 equal in volume to the full area of the
pipe, and that the said main valve is rapidly closed when the said trigger valve
closes, I am thus cuabled to use a smaller valve and a much lighter spung to
accomplish all that has been heretofore accomplished by a heavy spring and a very
large valve.
Secured to the casing or shell a³ and communicating with the chamber D', by
means of an opening, is a tube J, which passes tightly through the onter
asing A. The said opening 18 prevented from cominunicating with the outer air
by means of a breakable dish J', which disk is preferably made of cast iron (or
any suntable facturable material), tested to stand a given pressure, but which will
break when too great a strain is exerted upon it. This disk is preferably held u
place by a shoulder formed at an enlarged diameter of the tube J, into which,
against, the said disk J, screws a tube or retainer. The function of this disk is
that of an absolutely sure relief for the pressure of steam in a boiler, in case any of
the valves should from corrosion, or any cause, stick in their valve seats.
The modification shown in Fig. 2, which is intended especially for a relief valve,
differs from the construction shown in Fig. 1, in providing a shell G around the
branch containing the relief valve the upper end of the shell having a reduced
neck surrounding a spring E, and forming a shoulder upon which the auxiliary
sping II rests, the upper end of the sping bearing against the top of the case.
The lower edge of the shell G rests upon the outwardly projecting flange of
the main valve D', which has its packing d arranged to bear inside of the
shell a; the purpose of this arrangement is to add the assistance of the sping H
The shoulder
to the pressure of the steam in holding the main valve to its sent.
portion of the shell G has a series of segmental slots cut though it to allow the
upper slotted end of the shell a to pass. In this case the tension of the sping E
is preferably regulated by a tubular screw f', to which the haud wheel
secured, and the tension is held by the lock nut f'.
19
The operation of the device ie the same as Fig. 1, with the exception that the
spring H is used in addition to the steam pressure to hold the valve to its seat,
especially when transporting and also to prevent the valve from leaking when
raising steam in the boiler. A spanner may also be used underneath the transveise
pin to temporarily throw the valves from their sents, to relieve the cylinder
when the device is used as a cylinder chef valve, or to test the valves when used
as a safety valve.
The trigger valve b, as shown in Fig 2, may be located at the end of the tube B,
instead of above the chamber D', as shown in Fig. 1. The operation of the valve
is, however, the same in both views.
Fig. 3 represents another modification in which the tugger valve b and the rehef
valve Care arranged in parallel cases, instead of oue above the other. The
shell K has two chambers, and A', side by side, both connecting with the exhaust
port M, the chamber connecting through a channel. The main valve D 1B
substantially the same as in Fig. 1; its upper end fitted to slide over a branch
screwed into the projection in the underside of the cap K', of the case, and packed

page_text: with metal packing rings d'. Its lower tubular extension has laterally projecting
wings guided in the port a, and the tubular stem is bored to admit steam into
the chamber D to hold the valve 'th its seat until the pressure within the chamber
is released. The tubular stem of the trigger valve & has guide ribs at its upper
end to guide it in the neck or cap k. The rod passes through the tubular
stem, has a fixed collar or flange at its lower end, and a movable colla or
follower between which and the lower flange of the rod 19 compressed the set
spring E. The tension of the sping is regulated by a tubular screw 6³, which
passes through the cap and is held by a lock nut b
The relief valve C 18 sented in the lower end of the tubular piece ³, its stom
passes up through the case, and it is screw theaded at the top to receive tho
followe. c, which is fitted to play freely through the top K' of the case.
41s a perforated disk screwed into the shell K; and L is a spring coiled round
the stem of the relief valve, resting upon the perforated disk L, and pressing
upwardly against the follower c', to hold the relief valve C to its seat. An arm A,
projects upwardly from the cap and supports by means of bifurcated lugs, at its
upper end, a lever L' which is fulcramed upon a pin 1, which passes through said
lugs. The level has set screws and which pass through bosses formed on the
bar, one of which bears upon the stem or iod, which holds the valve b to its
seat, and the other bears upon the top of the stem of the relief valve C*.
It will be seen that when the trigger valve is thrown from its seat, the shorter
end of the lever will be thrown up, and the opposite end thrown down, thereby
throwing open the relief valve C, and relieving the chamber D' from pressure,
when the pressure on the other side of the valve D will quickly throw it from its
seat until the pressure is reduced and the trigger valve returns to its seat, when,
the pressure of the steam having fallen, the chamber D' will rapidly throw the
main valve closed.
In these valves the main valve D may, for certain purposes, such as when
desired to raise the hydrostatic pressure, be effectually closed by means of screws N,
having tapered ends, which are adapted to screw through the casing A at differont
points of its circumference, and overlap, and bind down tightly the said valve D
against the seat,
As the main feature of my invention is a chambered main valve in direct com-
munication with the boiler of generator, the said main valve being held to its seat
by the pressure in said generator until the pressure in the main valve chamber 18
relieved, and a relief valve for the main chamber, controlled by a small valve, the
underside of which is also exposed to direct pressure from the generator, and the
relief and the controlling on tugger valve connected on compled to move in unison,
whereby a small controlling valve and a light spring may be employed to control
the pressure in the boiler or regulator, it is obvious that any structural changes
may be made in the case and valves without departing from the spirit of iny
invention; therefore, I do not limit myself to the specific details of construction
ahonn.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed, 1 declare what I clain 18-
1. In a safety valve, the combination of a case, a main valve closing an opening
leading to a pressure generator, double exposed surfaces formed on said valve, a
pressure exerted upon each of said sin faces, for, and against the opening of said
valve, and a tension set trigger valve to relieve, at a certain pressure the pressure
ot one surface of said valve to allow the latter to open and relieve the pressure on
the other side of said valve, substantially as set forth.
2. In a safety valve, the combination of a case, a main valve closing an opening
leading to a pressure generator, exposed surfaces of different area on each side of
the valve disk, a pressure exerting upon each side of said disk, for the purpose of
closing and opening said valve by moving said disk, and'a tension set trigger valve
to relieve, at a certain pressure, the pressure on the largest area of said disk, to

page_text: allow the latter to open said valve to permit the escape of the pressure against the
said valve, substantially as set forth.
3. In a safety valve, the combination of a case, the main valve having interior
stean chamber communicating with a generator or boiler, a spring loaded relief
valve controlling the escape of steam fiom said chamber, and a trigger valve
exposed to a pressure from a generator and connected to the relief valve, so that
the tugge and relief valve move simultaneously in opening or closing, controlled
by the pressure in the generator. substantially as set forth.
4. The combination of a case, having a downwardly extending branch to conuect
to the generator or boiler and the laterally extending branch leading to the open
air or to a waste pipe, aud an enlarged chamber having at its lower end a seat for
the main valve, the main valve seated in said chamber and having a downwardly
extended tubular neck and a steam chamber within said main valve in communica-
tion with the generator through said tubular neck, the sping loaded relief valve
above the main valve, a trigger or controlling valve below the main valve, the
stems of the controlling and relief valves being connected together and passing
through the main valve, the stein of the relief valve passing through the top of the
case, a follower fitted to slide on the stem of the relief valve within the case, and
a regulating tubular screw tapped through the head of the case and bearing upon
the follower to regulate the tension of the spring by which the relief valve is held
to its sent, substantially as set forth.
5. The combination, as herein set forth, of the case, the main valve having
interior steam chamber communicating with the generator or boilet, a spring
loaded relief valve controlling the escape of steam from said chamber, a trigger
valve exposed to pressure of steam from the generator and coupled to move with
the relief valve, a sliding shell housing the main and relief valves and bearing
upon the main valve, and a spring bearing upon said shell to assist the steam
pressure in the chamber to hold the main valve to its seat, substantially as set
forth.
6 In a safety valvo, the combination of a case, a valve, and a breakable disk
exposed to a given pressure by the action of said valvo, the said disk being of
sufficient strength to resist a pressure greater than the said given pressure,
substantially as set forth.
7. In a safety valve, the combination of a case, a valve enclosed within said case,
an orifice, normally closed by said valve, leading from a pressure genciator into
said case, and a breakable disk secured in the shell of said case and exposed to the
pressure admitted auto said case by said valve, substantially as set forth.
n
8. In a safety valve, the combination of a case, a valve enclosed within said case,
an oufice, normally closed by said valve, leading from a pressure generator into
said case, and a breakable disk secured in the shell of said case and exposed to the
pressure admitted into said caso by said valve, the said breakable disk being made
of any suitable fiacturable material and being secured within a tubular recess, by
means of a tubular piece threaded and adjustable within sand recess, to bind against
said disk, substantially as set forth.
9 The improvements in safety valves, substantially as, aud for the purposes
herein before described, set forth, aud illustrated in the drawings annexed
Dated thus Seventh day of May 1895