Improvements in Check Valves for Steam Boilers, especially applicable to Stationary Steam Boilers Arranged in Multiple.
Year: 1899

page_text: Date of Application, 6th June, 1899-Accepted, 29th July, 1899
COMPLETE SPECIFICATION.
Improvements in Check Valves for Steam Boilers, especially
applicable to Stationary Steam Boilers Arranged in Multiple.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both
in the County of Lancaster, 118, New Street, Birmingham, in the County of
Warwick, and 322, High Holborn, in the County of Middlesex, Civil Engineer,
do hereby declare the nature of this invention (which has been communicated
to me by The Foster Engineering Company, of 21 and 23, Prospect Street,
Newark, in the State of New Jersey, United States of America) and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
The object of this invention is to provide a new and improved check-valve which
is automatic in action, and at the same time susceptible of being operated by
hand to tighten the valve-discs against their seats, and which is strong, sub-
stantial, and durable, effective in operation, and useful for many purposes,
although designed with special reference to its employment in connection with
that class or type of large stationary boilers wherein a plurality of boilers are
arranged as a battery, one valve being placed in operative connection with each
boiler in juxtaposition to the main steam pipe or header, the construction being
such that if any one boiler is disabled, as, for instance, by the blowing out or
bursting of a tube, the check-valve instantly closes and prevents the pressure
from the main steam pipe or header and the remainder of the boilers from blow-
ing back through the disabled boiler; the valve remaining closed until the
required repairs have been made and it is desired to connect the repaired boiler
with the main steam pipe or header.
I will now describe my invention with the aid of the accompanying sheet of
drawings in which a sectional view of my improved automatic check and hand
stop valve is shown, using numerals to indicate the different parts.
The numeral 1 indicates the valve-casing or shell having four openings 2, 3,
4, and 5. The openings 4 and 5 are adapted to be connected, respectively, with
the inlet and outlet pipes, while the openings 2 and 3 enable the valve stems
and springs, hereinafter described in detail, to be introduced, after which the
openings 2 and 3 are closed or covered by the cap, or closure plates 6 and 7,
held in proper position by screw bolts, or otherwise. The openings 2 and 3 are
substantially at right angles to the openings 4 and 5, and the valve casing or
shell is divided into two separate compartments 8 and 9, through the medium of
a continuous web 10 constructed to provide two separated rectilinear partitions 12
and 13, containing circular openings 14 and 15. The outer or upper edge of
the circular opening 14 is constructed to provide a valve-seat 16, and the lower
or outer edge of the circular opening 15 is also constructed to provide a valve-
seating 17. In connection with the valve seats I provide two valve-discs 18
and 19 which, in operation, approach each other to seat respectively against
the valve-seats 16 and 17, and which move away from each other to open the

page_text: valve, so that the pressure can flow from the central inner chamber 20 to the
outer chambers 8 and 9. The valve-discs may be of any construction suitable
for the purpose in hand, so that when they are opened or moved away from
the valve-seats, the pressure may flow through the openings 14 and 15 in the
partitions formed by the continuous web.
The cap or closure plate 6 is provided with a stuffing box 21, through which
the central spindle 22 passes for the purpose of forcing by hand the two valve-
discs simultaneously against the valve seats when desired, as will hereinafter
appear. The inner end of the spindle 22 is provided with a cross-head 23
having projecting fingers or lugs 24, which engage the ends of a cross-head 25
secured to or forming part of a screw-nut composed of an internally screw
threaded sleeve 26, engaging the outer screw threaded end 27 of a valve stem 28,
the axis of which is coincident with the axis of the spindle 22. A spiral or
other suitable spring 29, preferably a light phosphor bronze spring, is inter-
posed between the valve disc 18 and the cross-head 25 on one end of the internally
screw-threaded sleeve 26. The spring is normally held under slight compression.
The stem 28 passes centrally through the two valve-discs, and at its lower end
it is constructed or provided with a cross or T-shaped head 30 held against
rotary motion by fingers or lugs 31, projecting from the inner side of the cap,
or closure plate 7. A spring 32, like or similar to the spring 29, is interposed
between the lower or outer side of the valve dise 19 and the cross-head 30. This
spring is also held normally under slight compression. The cross-head 30 is
susceptible of moving longitudinally between the fingers or lugs 31, so that the
stem 28 can slide longitudinally and follow the valve disc 19 when the two valves
are forced towards each other, against the valve-seats 16 and 17, to shut off the
flow of fluid in either direction. The spindle 22 is provided with a hand wheel 33,
or other suitable means, by which to turn it for the purpose of rotating or turn-
ing the internally screw-threaded sleeve 26, which, as before stated, is in screw-
threaded connection with the outer end 27 of the stem 28. Through the medium
of the cross-head 23. fingers or lugs 24 and cross-head 25, the turning motion
of the spindle 22 is imparted to the internally screw-threaded sleeve 26, whereby
the stem 28 is moved longitudinally in one direction and the sleeve 20
is moved longitudinally in the opposite direction, for the purpose of
simultaneously closing the two valve-discs upon their valve-seats to close the
valve. The springs 29 and 32 are of such length that they exert but little
force or pressure on the valve discs when the latter are scated against or are
close to their valve-seats, and consequently while there is any volume of pres-
sure passing from the boiler to the main steam pipe or header, the valve discs
will be forced open sufficiently for the passage of the steam, but when the flow
of steam from the boiler to the main steam pipe or header ceases the pressure
at the sides of the valve discs is equalized, and the slight force or power exerted
by the springs will close the valve-discs and thereby prevent the back flow of
steam.
It will be seen from the foregoing that when the spindle 22 is turned in the
proper direction to move the stem 28 longitudinally in one direction, and the
sleeve 26 longitudinally in an opposite direction, the two independent springs 29
and 32 are more or less compressed and operate to force the two valve-discs
tightly against their seats, and, therefore, I make the two valve discs indepen-
dent of each other, and mount them upon the stem 28, so that they can be moved
longitudinally thereon by the springs.
If the two valve-dises do not tightly fit the valve-seats when they are closed
automatically, and hence fail to entirely or perfectly shut off the escape of steam,
the hand wheel 33 may be manipulated for the purpose of forcing the two valve-
dises towards each other, so that they may be tightly seated against the valve-
seats to effectually shut off escaping steam until such time as repairs shall have
been made and it is desired to connect the repaired boiler with the main. As
before stated, a valve constructed according to my invention is designed to be

page_text: placed on the outlet of each boiler of a battery of boilers, in juxtaposition to the
point where the boiler connects with the main steam pipe or header, so that if
one boiler becomes disabled from any cause whatever the valve automatically
closes and prevents the steam pressure from the main steam pipe or header,
and from the remainder of the boilers, from blowing back through the disabled
boiler.
In the application of the valve it should always be placed in such manner
that whether on a vertical or on a horizontal pipe the spindle and the stem
will lie substantially in a horizontal plane, so that the slight friction of the
valve-discs resting on their wings and on the stem 28 will prevent clattering.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim is:-
First. A combined automatic check and hand stop valve, consisting of a casing
or shell having a central inlet chamber and a partially surrounding outlet
chamber separated therefrom by a web having opposite openings, two valve-
discs movable towards each other to simultaneously seat upon the valve-seats
and close said openings, springs bearing respectively against the valve-discs
and normally forcing them towards each other against the valve-seats, but per-
mitting the flow of fluid pressure from the central inlet chamber to the partially
surrounding outlet chamber whilst preventing back flow of fluid pressure, and
hand-operated devices for forcing the two valve-discs towards each other tightly
against the valve-seats, substantially as described.
Second. An automatic check and hand stop valve, consisting of a valve-casing
or shell having a central inlet chamber and a partially surrounding outlet
chamber separated therefrom by a web having opposite openings, check-valves
arranged in said openings, and independent springs operating respectively upon
the two valves to normally press them towards one another against their seats
to close the openings in the said web, whereby fluid pressure is permitted to flow
in one direction from the inlet to the outlet chamber, through the two openings
in said web, but is prevented from flowing in the reverse direction, substantially
as described.
Third. An automatic check and hand stop valve, consisting of a casing or
shell having a central inlet chamber and a partially surrounding outlet chamber
separated therefrom by a web containing two opposite openings, valve discs fitted
to said openings and moving towards each other to close the same, springs which
normally move the valve discs against their seats, a threaded stem passing through
the valve-discs, a screw nut engaging the threaded part of the stem, and a spindle
for turning the nut, whereby both valve discs are simultaneously moved towards
cach other tightly against the valve-seats, substantially as described.
Fourth. An automatic check and hand stop valve, consisting of a casing or
shell having a central inlet chamber and a partially surrounding outlet chamber,
separated therefrom by a web containing opposite openings, two valve-discs
fitted to said openings, springs which normally hold the valve-discs against
their seats, a threaded steam passing centrally through the valve-discs, a screw
nut engaging the threaded part of the stem, a spindle extending to the exterior
of the casing or shell, and means for connecting the said spindle with the screw
nut for turning the latter and permitting it to move longitudinally independent
of the stem, substantially as described.
Fifth. An automatic check and hand stop valve, consisting of a casing or
shell having an inlet chamber and an outlet chamber, separated by a web con-
taining opposite openings, a stem having at one end a cross-head, means for
holding the cross-head against rotation while permitting the stem to move longi-
udinally, two valve-discs loosely mounted on the stem and movable towards cach
other against their valve-seats, a spring interposed between one of the valve-

page_text: discs and the cross-head of the stem, a screw-nut engaged with a threaded end
of the stem and having a cross-head, a spring interposed between the cross-head
of the nut and the other valve-disc, and a spindle engaged with the cross-head
of the nut, substantially as described.
day
.
W. P. THOMPSON & Co.,
11, Burlington Chambers, New Street, Birmingham,
Also of Liverpool, London and Manchester,
Patent Agents for the Applicant.