Improvements in Check Valves for Steam Boilers.
Year: 1895

page_text: Date of Application, 22nd Nov., 1895
Complete Specification Left, 8th Aug., 1896-Accepted, 3rd Oct., 1896
PROVISIONAL SPECIFICATION.
Improvements in Check Valves for Steam Boilers.
We, JAMES STEVEN WYNDHAM, of No. 14 Kyreilog Street, Cardiff, in the
County of Glamorgan, Engineer, and JOHN HARRY HALLETT, of No. 123 Bute
Street, Bute Docks, Cardiff, in the County of Glamorgan, Engineer do hereby
declare the nature of this invention to be as follows:-
This invention relates to an improved check valve, more particularly applicable
to the pump delivery pipes of steam engines.
It is the common experience of engineers that the ordinary valve used for this
purpose, becomes quickly deranged, more particularly on account of the concussion
on the up-stroke, the head of the valve hammering violently against the stop, and
the valve beating heavily against the face or mitre, upon the down stroke.
In this invention we make use of the ordinary seating bush, but with a greater
surface upon the top flange part for the purpose hereinafter described.
The valve is of a disc form and is somewhat larger in diameter than ordinary, so
that a projecting lip is formed all round on its outer edge, the object of this
enlargement being, as also that of the seat, to allow of a portion of the water to be
partially imprisoned between the two faces, the expelling of this water forming a
cushion for the downward stroke of the valve and so preventing, to a very large
extent, the great wear and tear ordinarily experienced in this direction.
The back or head of the valve has a projecting ridge on its outer periphery so
that there shall be a dished part for containing water. A central pin projecting
upwards from the centre acts as a guide and runs up into the bottom end of the
screw-down spindle which passes through the centre of the valve box cover.
Another upward projecting ring is also formed on the inner part surrounding the
root of the central pin.
A spiral spring may be placed within the hole in the end of the screwed spindle,
this spring resting against the top of the central pin of the valve and keeping it
down on to its face.
An enlarged guard is formed upon the lower end of the screwed spindle having a
cup-shaped recess in the middle. This guard is made to fit the top of the valve,
the imprisoned water between the valve and the guard forming a cushion for the
prevention of wear and tear on the upstroke of the valve.
Dated this 22nd day of November 1895,
PHILLIPS & LEIGH,
Agents for the Applicants.
Improvements in Check Valves for Steam Boilers.
We, JAMES STEVEN WYNDHAM, of No. 14 Kyveilog Street, Cardiff, in the
County of Glamorgan, Engineer, and JOHN HARRY HALLETT, of No. 123 Bute
Street, Bute Docks, Cardiff in the County of Glamorgan, Engineer, do hereby
declare the nature of this invention and in what manner the same is to be
Price 8d 1

page_text: performed, to be particularly described and ascertained in and by the following
statement :-
This invention relates to improvements in check valves such as are used on the
water supplies to steam boilers, and to which it is particularly applicable.
It is the common experience of engineers that the valve ordinarily used as a
check valve on water supplies to steam boilers, gets out of working order very
quickly, because at the end of each lift, the crown of the valve hammers violently
against the stop and also because the valve beats itself heavily on the mitro or seat
at the end of each drop of the valve.
The object of the present invention is to prevent the above mentioned hammering
and beating.
The invention includes improved means for providing a water cushion between
the valve face and its seating, during the drop of its valve.
It also includes improved means for providing a water cushion between the back
of the valve and the valve stop, during the lift of the valve.
It further includes the combination with the valve, valve seat and valve stop, of
improved means for providing a water cushion between the valve face and its
seating during the drop of the valve, and a water cushion between the valve and the
valve stop during the lift of the valve.
Referring to the accompanying figures
Figure 1 is a vertical section through the centre of an ordinary check valve box
fitted with our improved valve guard and spindle.
F is the
Figure 2 is a vertical section of a modification of the present invention.
Referring to Figure 1, A is the flange by which the valve box is held to the
boiler or to the pipes. B is the flange by which the lower part of the said box is
held to the feed pump pipe; C, the cover of the valve box; and e, the stuffing
box, therein. The foregoing parts are of the same construction as heretofore.
D is the valve seat or mitre; and E, the flange outside the same.
improved valve, F1, its mitre; fits lip extending round the outer edge of it; and
G, a central annular cavity in the back of the valve formed by the lip being in a
plane higher than that of the valve F. The mitres D and F', being the actual
valve seat and the contacting valve surface, respectively, are, as far as they them-
selves are concerned, the same as heretofore. The lip stands in such a position
relatively to the flange E, that when the latter is on its scat or mitre D, the under
face of the lip is separated from the flange E by a distance H.
I is the bottom end of the sciewed spindle J and forms the valve stop. The
spindle is tubular throughout its length. The valve stop I is in the form of an
inverted cup having a large horizontal rim i. The cavity of the valve stop I
corresponds in respect of its contour with that of the crown of the valve F,
whilst the cross section of the rim i corresponds with that of the cavity G. j is the
screw thread on the tubular spindle J. It engages in the depending extension L of
the cover C. The spindle passes out through the stuffing box c for a sufficient
distance and is there fitted with a hand wheel R for adjusting the lift of the
valve For for holding it down upon its seat, according to the distance at which the
end I is set over such valve. The stop I stands at a sufficient distance above
the valve F to allow of its maximum lift. K is a collar on the spindle J,
adapted by its position thereon, to limit the upward motion of the said
spindle, by contacting with the opposite end of the extension L. It also
serves, when screwed up tight against the latter, to form a water and steam tight
closure between the stuffing box c and the interior of the valve box, thereby
relieving the stuffing box from steam pressure.
N is the valve spindle fast to and projecting upwards from the crown fl of the
valve F and entering the bore of the spindle J, whereby the accurate motion of the
valve F is secured. O is a set screw adapted to work up and down the screw thread o
in the top end of the spindle J, and o¹ is a nut for locking it in any desired position.
P is a spiral spring within the tube J and between the spindle N and a
prolongation o² of the set screw O. This spring is sufficiently strong to, using the

page_text: inner end of the set screw O as a base, keep the valve F down upon its seat
independently of the pressure upon the back of the latter.
Our invention operates in respect of its several features as follows:-
:―
WATER CUSHION DURING THE DROP OF THE VALVE.
The improved means for providing this consists of the lip f, the flange E and
the spring P. At the moment when the valve begins its drop under the action of
the said spring, there is obviously an annulus of water between the said lip and
flange and E. The whole of this annulus with the exception of as much as is
represented by the space H must be displaced by the spring P before the valve F
can reach its seat. It is the yielding resistance of the above mentioned annulus of
water to the action of the spring P, that constitutes the water cushion in question,
such yielding being delayed by the opposition to the motion of the water away
from the axis of the valve due to the presence of the opposite portion of the
valve box.
WATER CUSHION DURING THE LIFT OF THE VALVE.
The improved means for providing this consists, according to one modification of
the invention of the lip the cavity G in the back of the valve, the rim i on the
valve stop I immediately above the said cavity, the valve crown f¹ and the cavity i¹
in the valve stop immediately above the said crown. At the moment when the lift
of the valve F commences, there is obviously an annulus of water between the valve
back and crown beneath and the stop rim and the cavity above. The whole of
this annulus must be removed before the lift can be completed, and it is its yielding
resistance to the suction acting on the under side of the valve, that constitutes the
water cushion in question, such yielding being delayed by the opposition to the
motion of the water away from the axis of the valve spindle N, due to the presence
of the inner edge of the lip f and the cup i.
According to the other modification of the invention the one illustrated in
Figure 2, the central annular cavity G and the rim i are dispensed with and both
valve crown f¹ and cup shaped cavity i¹ enlarged accordingly.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. A check valve for steam boilers, in which the presence of a water cushion is
provided for both between the valve and its seat and between the valve and its
stop, as and for the purpose specified.
2. The combination of hip extending round the outer edge of the valve; a central
annular cavity in the back of the valve and a rim on the valve stop of the same
cross section as the said cavity.
3. The combination of lip extending round the outer edge of the valve; a central
annular cavity in the back of the valve; a rim on the valve stop of the same cross
section as the said cavity and a flange outside the valve seat and standing beneath
and opposite the lip above mentioned.
4. The combination of lip extending round the edge of the valve, a central
annular cavity in the back of the valve; a rim on the valve stop of the same cross
section as the said cavity; the valve crown and a cup shaped cavity in the valve
stop corresponding in respect of its contour, and that of the said crown.
5. The combination of lip extending round the outer edge of the valve; a central
annular cavity in the back of the valve; a rim on the valve stop of the same cross
section as the said cavity; the valve crown; a cup shaped cavity in the valve
stop corresponding in respect of its contour, with that of the said crown, and a
flange outside the valve seat and standing beneath and opposite the line above
mentioned.

page_text: 6. The combination of flange outside the valve seat; a lip extending round the
outer edge of the valve and standing opposite the said flange; a tubular guide
adapted to receive the valve spindle; and a spring with the said guide adapted by
acting upon the said spindle to keep the valve down on its seat.
7. The combination of flange outside the valve seat; a lip extending round the
outer edge of the valve and standing opposite the said flange; a tubular guide
adapted to receive the valve spindle; a spring within the said guide, adapted by
acting upon the said spindle to keep the valve down on its seat, the valve crown
and a cavity of a corresponding contour immediately above it in the valve stop.
Dated this 8th day of August 1896.
PHILLIPS & LEIGH,
No. 22 Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicants.