Improvements in Stop and other Valves,
Year: 1894

page_text: Date of Application, 17th Apr., 1894
Complete Specification Left, 14th Dec., 1894-Accepted, 19th Jan., 1895
PROVISIONAL SPECIFICATION.
Improvements in Stop and other Valves,
We, JOHN ADDY HOPKINSON and JOSEPH HOPKINSON, both of the Firm of
J. Hopkinson. & Co. Ltd., of Huddersfield, in the County of York, Engineers, do
hereby declare the nature of this invention to be as follows:-
This invention relates to stop and other valves, and has for its chief object to
provide improved means for securing the valve seat in position in the casing while
permitting of the ready removal thereof when required for repairs, re-grinding or
for other purposes and the equally ready replacement without necessitating the
breaking of the joints between the valve casing and the pipes or boiler for example
to which it may be connected.
Our improved mode of securing the seats is specially advantageous in cases where
the seat and casing are constructed of different metals and where, consequently, the
difference of expansion is liable to set up severe stresses such as would cause the
warping and ultimate loosening of the seat.
By our present improvements the defects inherent in the usual modes of securing
the seats are overcome, and provision is made whereby a seat of brass for example
can be fitted to an iron casing without any liability to working loose or warping,
and at the same time admitting of ready removal and replacement as above stated.
By our present invention we provide a seat ring which is absolutely free to expand
radially to accommodate itself to variations of temperature, it being so attached to
the casing that it is unconfined on every side.
We provide the valve casing with an annular projection around the end of the
aperture which is to be closed by the valve proper. Said annular projection is
formed on a ring preferably made of the same metal as the body of the casing which
ring accurately fits a recess provided in the casing to receive it so as to make a
fluid tight joint therewith. The mode of attaching the seating ring is such as will
allow of its ready removal whenever required, and in this respect it differs essen-
tially from the construction described and claimed in the Specification of the prior
Patent No. 4402 A.D. 1891. We secure the seat ring in place according to this
invention by screwing or by equivalent means, the seating ring being external to
the annular projection aforesaid, that is to say, the seating ring is provided with
female threads and the aforesaid annular projection with male threads and the ring
is screwed on to the annular projection so that the seating ring embraces the
part to which it is attached and is therefore not confined radially nor is it subjected
to restraint by pressure on its upper surface. The screw threads may be continuous
or they may be interrupted. In the latter case a fraction of a turn will suffice to
disengage and re-engage the seating ring.
The aforesaid annular projection is faced to make a fluid tight joint with a true
surface formed on the seating ring.
We sometimes form the annular projection integral with the casing and attach
the seating ring thereto or we place around the outside of the said annular projection
a detachable ring, preferably of the same metal as the casing on which the seating
ring is screwed as aforesaid.
We sometimes provide a key, wedge, screw or other equivalent means to prevent
the seating ring from accidentally unscrewing.
By our improvements we can dispense with cross bars in the seat even in valves
of large diameter.

page_text: Another part of my invention contemplates providing the valve proper with a
ring or with rings to constitute the working face or faces thereof, said ring or
rings being attached to the valve in the manner above indicated with reference to the
seating rings.
Dated this 17th day of April 1894.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.
Improvements in Stop and other Valves.
We, JOHN ADDY HOPKINSON and JOSEPH HOPKINSON, both of the Firm of
J. Hopkinson & Co. Ltd. of Huddersfield, in the County of York, Engineers, do
hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement :-
This invention relates to stop valves and other valves, and has for its chief object
to provide improved means for securing the valve-seat in position in the casing
while permitting the ready removal thereof when required for repair, or for other
purposes and the equally ready replacement or renewal thereof without necessitating
the breaking of the joints between the valve-casing and the pipes or boiler, for
example, to which the casing may be connected.
Our improved mode of securing the seats is particularly advantageous in those
instances where the seat and casing are constructed of different metals and where,
consequently, the difference of expansion when the valve is subjected to a high
temperature is liable to set up severe stresses such as would cause the warping and
ultimate loosening of the seat.
By our present improvements the defects inherent in the usual modes of securing
the seats are overcome, and provision is made whereby a seat of brass, for
example, can be fitted to an iron casing without any liability to working loose or
warping, and thereby causing leakage when subjected to high temperature, while at
the same time admitting of ready removal, replacement and renewal as hereinabove
stated.
According to our invention we provide a seat ring which is so attached to the
casing that it is absolutely free to expand radially or laterally and can thus
accommodate itself without strain to variations of temperature.
Referring to the accompanying drawings,
Figure 1 is a central section of a parallel sliding valve and valve-casing provided
with our present improvements.
Figure 2 is a plan of that face of the casing to which the cover is attached,
showing also the seat rings and the locking keys hereinafter described.
Figure 3 is a side elevation of a ring to be inserted in the valve casing as
hereinafter described.
Figure 4 is a section of the seat ring.
Figure 5 is a front elevation of the said ring.
Figure 6 is a side elevation of the aforesaid rings screwed together.
Figure 7 is a section of the lower part of a valve casing for a mushroom type of
valve showing the valve resting on the seat.
Figure 8 is a section of half of the casing on the line x, x Figure 7.
Like letters denote corresponding parts throughout the drawings.
A is the valve-casing; B, B, Figure 1, are the discs of the parallel sliding-valve;
D, D are the seat rings.
The valve-casing is recessed as shown at E' to receive metal rings E which

page_text: accurately and tightly fit in the said recesses and form fluid-tight joints therewith.
The rings E are preferably made of the same metal as the body of the casing.
Each ring E is formed with an annular extension or projection E Figure 3 which
is screw-threaded externally. The seat ring D is screw-threaded internally and
fits the screw threaded annular extension E. The screw-threads are preferably
square or rectangular and may be continuous or they may be interrupted. In
the latter case a fraction of a turn will suffice to disengage and re-engage the
seat ring.
The end E³ Figure 3 of the annular projection E is accurately faced to make a
perfect fluid-tight joint with the inner face D' of the ring D so that when the latter is
screwed home on the annular projection E there will be no escape of fluid beneath
the seat ring. In some instances the fluid tight joint is made between the faces E
and D' instead of as above described between the faces E³ and D'
The above described mode of securing the seat ring to the casing is such as will
allow of the ready removal of the ring whenever required, and in this respect it
differs from the construction described and claimed in the Specification of our prior
Patent No. 4402 A.D. 1891.
It will be observed that the seat ring shewn in the drawings embraces, and is
wholly external to, the part to which it is attached, that is to say, the metal which
has the greatest expansion with any given increase of temperature, is in the best
possible position for ensuring its free expansion relatively to the other metal whereby
it is supported.
Any pressure applied through the screw threads acts in a direction parallel to the
axis and will have no binding or restraining action on the seat ring that would
interfere with the free radial or circumferential expansion or contraction of the
said ring. Consequently when the seat ring is screwed home on the part E' and
the faces E and D' are in contact, the said faces will not tend to separate
notwithstanding the variations of temperature to which they may be subjected.
We sometimes make the annular projection E³ integral with the valve casing and
screw the seat ring directly thereupon, or we place around such integral projection
a detachable ring (preferably of the same metal as the casing) to which the seat
ring is screwed as aforesaid.
The face D³ of the seat ring is prepared in the usual manner to form a fluid-tight
joint with the valve.
The seat ring is preferably so made that when it is screwed home on the part E
it is still capable of a slight amount of lateral movement. To prevent its being
accidentally unscrewed, we provide a key F which in the arrangement shown in
Figures 1 and 2 is dropped into a recess or pocket F provided in the casing to
receive it and is held therein by the upper part A' of the casing. The lower end
of the key is shaped to enter a notch or recess D' Figure 5 in the edge of the seat
ring and when so engaged with the ring it forms a stop to prevent the latter from
turning. When the key is removed, the seat ring may be unscrewed by suitable
means provided for the purpose.
All the parts are made to a standard and similar parts are made inter-
5 changeable.
1
When the valve is in use there are no stresses that tend to disturb the seat, and
the metal parts when in close contact will withstand any pressure to which the
valve may be subjected.
Moreover as our improved construction allows the seat ring to be securely united
0 to the projection E while fitting loosely thereon there is little or no liability to
its binding whether it is made of the same metal as the casing or of a different
metal.
In Figures 7 and 8 we have shown our improvements applied to a valve of the
mushroom type.
The construction is substantially the same as that above
5 described. In this case however the retaining key F is shown projecting through
an opening F³ in the side of the casing and is retained in place by a screw plug G.
The key is so shaped that it cannot turn in the opening F. If desired we may

page_text: employ a key placed in a recess and held down by the lid as shown in Figures 1
and 2.
It is not necessary to furnish the seat with cross bars even when it is of large
diameter.
By our invention we also provide for applying to each valve disc in the case of
a parallel sliding valve or to the mushroom or like valve a removable ring to form
the working face of the valve or disc, said ring being attached to the valve in the
same manner as the seat rings above described are attached to the annular
projections E. Such removable rings are shown in the drawings and need not be
further described.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is :-
1. A removable and renewable valve-seat attached to the body or casing by
screwing or equivalent means whereby the surfaces forming the fluid tight joint
are held together by pressure in an axial direction distributed over the said
surfaces, without any such radial pressure as would interfere with the free
expansion or contraction of the seat.
2. A valve-seat consisting of a ring which is wholly external to the part
whereby it is held in place in the valve body or casing, for the purposes specified.
3. The seat ring attached to the casing by means of screw threads, substantially
as described.
4. A compound ring or valve made of two different metals secured detachably
together, substantially as described, and for the purpose specified.
5. A removable and renewable valve seat, attached to the body or casing by
screw-threads or otherwise, having a notched flange so arranged in combination
with a key that the two faces forming the fluid tight joint cannot be separated
without removing the key.
6. A stop valve constructed substantially as described with reference to
Figures 1 and 2 or to Figures 7 and 8 for the purpose specified.
Dated this 14th day of December 1894.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.