Improvements in or relating to Valve Seats.
Year: 1895

page_text: Date of Application, 7th Mar., 1895
Complete Specification Left, 21st Nov., 1895-Accepted, 7th Mar.,
1896
PROVISIONAL SPECIFICATION.
Improvements in or relating to Valve Seats.
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 bereby declare the nature of this invention to be as follows:-
:―
This invention relates to removable and renewable valve sents of the kind or
class that are not held circumferentially by the valve casings or supports on which
they are fitted and that consequently are free to expand and contract without
detriment to the efficiency of the valve and without working loose. An instance
of such a valvo scat is to be found in the Specification of Letters Patent granted
to us No. 7633 of A.D. 1894. Heretofore our improved valve seats of this type
have been retained in position by mechanical means applied to the seat ring
externally to the inner diameter of the said ring.
According to our present invention we provide for retaining the seat ring in
position by mechanical means applied within the inuer diameter of the seat.
For
In some instances we apply the retaining device at the centre of the seat.
this purpose we provide the body of the casing with a supporting ring preferably
made of the same metal as the casing and having an annular projection as described
in the Specification above referred to but having a cross bar. We provide the
seat ring with a similar cross bar, and we secure the seat ring in place by a set-
screw or stud or bolt and nut, or equivalent fastening passed centrally through or
into the said cross bars. The said central fastening is preferably so constructed
as to prevent the turning of the seat ring on its axis. The lower face of the
seat ring is accurately prepared to make a perfect fluid tight joint with the prepared
face of the supporting ring aforesaid and when in position it rests on the said fnco
without touching the supporting ring at any other point. Instead of fitting the
seat ring to a supporting ring detachable from the valve body as above described
we may apply it in a similar manner directly to uu annular projection integral with
the valve body. This form of seat is advantageously applicable not only to
mushroom and parallel slide valves but also to sluice wedge valves.
The cross bars in the seat and supporting rings may be integral with the said
rings or separate therefrom. In lieu of bars extending completely across the said
rings we sometimes provide arms or projections extending from one side of the rings
partially across the thoroughfare through the valve. In some instances the
attachment for the seat ring is independent of the supporting ring; for example
in the case of a junction valve fixed on a steam boiler the seat ring may be attached
to a cross bar or its equivalent in the seating block or in the boiler; or again in
the caso of a valve having a globular body usually fixed to pipes the seat ring may
be furnished with a central spindle attached directly to the valve body. But in
all cases the attachment is such that a perfect fluid tight joint will exist between
the seat ring and its support.
We
The upper face of the seat ring is prepared as usual to receive the valve.
prefer that the seat face shall be bevelled or recessed on its inner circumference
to furnish a surface under the valve proper on which the fluid pressure within the
valve body can act to maintain the seat ring tightly pressed against its support,
thereby preventing leakage under the said ring.
We in son.e instances provide for securing the seat ring by means of two or

page_text: more internal book-like projections thereon that ongage with projections or lugs
on the inner circumference of the supporting ring. The engaging faces of these
projections are inclined so that when the seat ring is placed in position and then
turned, the said faces operate to hold the seat ring tightly in place, somewhat in
the manner of a bayonet joint.
We also prefer to provide the seat ring with an external flange or rim that
surrounds the annular projection of the supporting ring, and prevents lateral
movement of the seat ring.
This seat ring is unconfined at its circumference and is therefore quite free to
expand and contract with the variations of temperature; it can be removed and
replaced when required with the greatest facility, and it will keep tight under all
conditions of pressure and temperature.
Dated this 7th day of March 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicants.
Improvements in or relating to Valve Seats.
We, JOHN HENRY HANSON of 20 Ramsden Street, Huddersfield in the County
of York, Laud Agent Surveyor and Valuer, Executor of the late John Addy
Hopkinson of J. Hopkinson & Co., Ltd. Engineers, of Huddersfield aforesaid and
JOSEPH HOPKINSON also of the said Company, 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 removable and renewable valve seats of the kind or
class that are not held circumferentially by the valve casings or supports on which
they are fitted and that consequently are free to expand and contract without
detriment to the efficiency of the valve and without working loose. An instance
of such a, valve seat is to be found in the Specification of Letters Patent No. 7633
of A.D. 1894. Heretofore the improved valve seats of this type have been
retained in position by mechanical means applied to the seat ring externally to the
inner diameter of the said ring.
According to our present invention we provide for retaining the seat ring in
position by mechanical means applied within the inner diameter of the seat.
In some instances the retaining device is applied at the centre of the scat,
and in other instances it is near the circumference but within the inner diameter
of the seat.
Referring to the accompanying drawings
Figure 1 is a central section through a valve seat of a mushroom valve showing
our improved central fastening therefor.
Figuro 2 is a central section of a similarly secured seat for a wedge valve.
Figure 3 is a central section of a valve casing, and of a seat ring attached to
the casing by means of a central bolt or spindle.
Figure 4 is a central section on a larger scale of a valve in which the seat ring
is secured by a bolt integral with the seat ring and passing through the valve
casing.
Figure 5 is a central section of a valve seat illustrating a modified mode of
securing the same.
Figure 6 is a plan of the supporting ring of the removable seat ring.
Figure 7 is a section on the line y, y Figure 5.
Like letters of reference denote corresponding parts throughout the drawings.
A is the supporting ring preferably made of the same metal as the valve casing
and tightly secured therein; B is the seat ring.

page_text: When we apply the retaining device at the centre of the seat we according to
one construction furnish the supporting ring with a cross bar a Figure 1
and we provide the scat ring with a similar cross bar 6' and secure the
seat ring in place by a set screw, stud, or bolt and nut d or equivalent
fastening passed centrally through or into the said cross bars. The said central
fastening is preferably so constructed as
to prevent the turning of the seat
ring on its axis, for example the central part of the bolt may be made square to fit
a corresponding square hole in the centre of the cross bar 6'. The lower face of
the seat ring is accurately prepared to make a perfect fluid-tight joint with the
prepared face of the supporting ring A aforesaid and when in position it rests on
the said face without touching the supporting ring at any other point. The
aforesaid method of attachment is advantageously applicable to mushroom valves
und to parallel slide valves, and also to sluice wedge valves as shown in Figure 2.
Instead of applying the seat ring to a supporting ring detachable from the valve
body as above described we may apply it in a similar mauner directly to an annular
projection integral with the valve body.
The cross bars in the seat and supporting rings may be integral with the said
rings or separate therefrom. In lieu of bars extending completely across the said
rings wo sometimes provide arms or projections extending from one side of the
rings partially across the thoroughfare through the valve. In some instances the
attachment for the sent' ring is independent of the supporting ring; for example
in the case of a junction valve fixed on a steam boiler the seat ring may be
attached to a cross bar or its equivalent in the seating block or in the boiler; or
again in the case of a valve having a globular body such as those shown in
Figures 3 and 4, the seat ring may be furnished with a central bolt or spindle d
attached directly to the valve body or casing. But in all cases the attachment is
such that a perfect fluid-tight joint will exist between the seat ring and its
support. In the construction shown in Figure 3 the spindle d is screwed into the
casing at, whereas in the construction shown in Figure 4 it passes through the
casing and is fastened by a nut & outside the casing.
The construction shown in Figure 4 is one that we preferably employ for small
gun metal valves or for other valves where the valve body and seat are made of
the same metal. It will be observed that in this construction the supporting ring
is integral with the valve body, and the bolt d is integral with the sent ring. It
will be further observed that the seat ring can be readily removed for repair and
replaced and should a now seat ring be required it can be easily applied as the
parts are made intorchangeable.
The upper face of the seat ring is prepared as usual to receive the valve, and
ie preferably bevelled or recessed at 6 to furnish a surface under the valve proper
on which the fluid pressure within the valve body can act to maintain the seat ring
tightly pressed against its support, as described in the Specification of Lettore
Patent No. 3690 A.D. 1895.
We in some instances provide for securing the sent ring by means of two or more
internal hook-like projections 6 (Figure 5) thereon that ongage with projections
or lugs a on the inner circumference of the supporting ring. The engaging
faces of these projections are inclined as shown so that when the seat ring is
placed in position and then turned in the proper direction the said faces look with
each other and operate to hold the seat ring tightly in place, somewhat in the
manner of a bayonet joint.
We also prefer to provide the seat ring as shown in Figures 2, 3, 5 and 7 with
an external flange or rim 6 that surrounds the supporting ring A, and prevents
displacement of the seat ring by its being moved bodily to either side of the
centre. This flange however in nowise interferes with the lateral expansion or
contraction of the seat ring which is unconfined at its circumference and is there-
fore quite free to expand and contract with the variations of temperature. The
Beat ring can be readily removed and replaced when required, and will keep tight
under all conditions of pressure and temperature.

page_text: Having now particularly described and ascertained the unture of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. A valve-seat-ring which is held to its support by devices within the inner
diameter of the valve seat.
2. The valve-seat-ring and supporting ring having the cross bars a and b in
combination with a central fasteuing such as d, d' substantially as described.
3. Securing the valve-seat-ring by a bolt d or equivalent fastening attached
directly to the valve casing, substantially as described.
4. The seat-ring secured to its support by a device similar to a bayonet joint,
substantially as described.
5. The seat-ring provided with the external flange & substantially as, and for
the purpose, specified.
6. A valvo having its seat-ring constructed and mounted substantially as
described with reference to Figure 1, or to Figure 2, or to Figure 3, or to Figure 4
or to Figures 5, 6 and 7 for the purpose specified.
Dated this 20th day of November 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicants.