Improvements in Gate-valves.
Year: 1889

page_text: Date of Application, 16th Feb., 1889
Complete Specification Left, 15th Nov., 1889-Accepted,. 21st Dec., 1889
PROVISIONAL SPECIFICATION.
Improvements in Gate-valves.
I, JOHN DEWRANCE, of 158, Great Dover Street, Lambeth, in the County of Surrey,
Engineer, do hereby declare the nature of this invention, (a communication to me
from abroad from Rufus N. Pratt, of Hartford, in the County of Hartford and State
of Connecticut,.o
..one of the United States of America, Manufacturer), to be
follows:-
als
This invention relates to the class of valves known as straight-way gate-valves, and
its' object is to provide a valve of this description having tight joints when closed; and
being, moreover, simple and cheap in construction, durable and so made that the
wearing parts may at little cost be easily and quickly renewed without disuniting the
valve from its connections:
To accomplish this end, a valve-chamber or -body is employed provided with ports
for the passage of the fluid and fitted with a gate for opening and closing the said
ports; the valve-seats, which are formed separately, being held in position between
the body and the gate by a holder which may be withdrawn through an opening in
the valve-casing when the bonnet thereof is removed. The seats may thus be
renewed without disturbing the valve-connections.
The body of the valve is cast to the requisite shape and has inclined seat-faces
round the ports. The seats are of uniform thickness. The gate is preferably cast
solid with faces tapered to correspond with the inclined seat-faces on the body of the
valve. The opening in the latter is covered by a bonnet bolted to the top of
the body. This bonnet carries the raising and lowering. spindle and screw in
the customary manner.
The seat-holder consists of a frame of thin metal, (by preference, cast), oblong
in cross section and of a size which permits it to drop easily into the opening in the
valve-body between the ports when the valve-bonnet is removed. Openings some-
what larger than the port-openings are made in two sides of the frame. The seats' are
loosely placed within these openings; the walls of which should be bevelled outwards.
The said seats' are somewhat thicker than the sides of the seat-holder and may be made
of soft'metal, or of asbestos and 'rubber intimately mixed and hardened by heat and
pressure. They are supported by the seat-holder; their outer faces lying against the
inclined 'seat-faces' on the valve-body; so that the openings through the seats' coincide
with the ports, whilst the inner surfaces of the seats project within the inner faces' of
the seat-holder in position for making close contact with the gate when lowered.
When the bonnet of the valve-casing is secured in place, inwardly-projecting 'lugs
formed thereon rest upon the seat-holder and prevent the latter rising when the screw
spindle is rotated and the gate raised.
In a modified form of construction, the seats are supported on their under sidės in
grooves cut in rims which are cast round the bottoms of the 'seat-faces. The" seat-
holder, which, as before described, consists of a frame oblong in cross section, has in
this case the under part cut away; the lower edge of two of its sides being so formed
that they rest upon the upper edges of the seats and hold them with their bottom
edges in the grooved rims in position for the gate to be seated properly against them
when closed down. In this as in the former case, when the bonnet is removed;
the holder can be withdrawn and the seats renewed without disturbing the valve
connections; the bonnet when in place keeping the seat-holder down.
According to another modification, two seat-holders, each corresponding with one
of the two wider sides of the seat-holder previously described are employed: Thus
the seat-holders in this modification resemble thin plates, and may be rolled or stamped'

page_text: to shape. They serve to support the seats, and are themselves in turn held to the
sides of the valve-body by lugs which are cast integrally therewith. Or, if preferred,
they may be kept in place by setting the lower edge of each holder in a groove in the
bottom of the opening in the valve.
It will be obvious that instead of the seat-faces being arranged at an inclination to
one another, they may be parallel; the thickness of each seat gradually increasing
from its upper to its lower part to correspond with the taper of the gate. Under such
circumstances, the seat and carrier are so shaped as to prevent the former turning
round in the latter.
Valves constructed as herein before described can be produced at moderate cost
and, when worn, may be easily renovated by simply removing the bonnet, lifting out
the seat-holder and substituting new seats. The latter being easily produced and
occupying little space, a large number may be conveniently kept on hand. As the
edges of the seats do not serve to make the joint which is to prevent leakage, no
special care in fitting these parts is required, whilst the elasticity of the seats them-
selves compensates for any inequality between the angle of the seat-faces and that of
the faces of the gate. Thus the latter need not be complicated in construction in
order to ensure close contact with the seats. The seat-holders are simple, and even
when roughly made answer for holding the seats in proper position.
Dotal this Oth don of 1000
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Gate-valves.
I, JOHN DEWRANCE, of 158, Great Dover Street, Lambeth, in the County of Surrey,
Engineer, do hereby declare the nature of this invention (a communication to me
from abroad from Rufus N. Pratt, of Hartford, in the County of Hartford and State
of Connecticut, one of the United States of America, Manufacturer), 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 the class of valves known as straight-way gate-valves, and
its object is to provide a valve of this description having tight joints when closed, and
being, moreover, simple and cheap in construction, durable, and so made that the
wearing parts may at little cost be easily and quickly renewed without disuniting the
valve from its connections.
To accomplish this end, a valve-chamber or -body is employed provided with ports
for the passage of the fluid and fitted with a gate for opening and closing the said
ports; the valve-seats which are formed separately being held in position between
the body and the gate by a holder which may be withdrawn through an opening in
the valve-casing when the bonnet thereof is removed. The seats may thus be renewed
without disturbing the valve-connections.
In the accompanying drawings, Fig. 1 is a longitudinal section of a valve con-
structed in accordance with the present improvements, Fig. 2 is a plan thereof, the
bonnet and spindle having been removed; Fig. 3 is a transverse section of the seat-
holder and valve-chamber or body; Fig. 4 is a face view of the seat-holder shewing
the removable seat. Fig. 5 shews in longitudinal section a valve-chamber or-body
fitted with a modified form of seat-holder; Fig. 6 is a transverse section thereof, and
Fig. 7 is a plan of the seat-holder. Fig. 8 is a longitudinal section shewing another
forin of seat-holder; Fig. 9 is a face view of the latter shewing the removable seat ;
and Fig. 10 is a vertical section through the same parts.
The body 1 of the valve is cast to the requisite shape and has inclined seat-faces 2
round the ports. 3 is the seat-holder, 44 are the seats held in position by the seat-
holder aforesaid, 5 is the gate, preferably cast solid with faces tapered to correspond

page_text: with the inclined seat-faces on the body, of the valve, and 6 is the bonnet, which is
bolted to the top of the body and carries the raising and lowering spindle and screw
in the customary manner.
In Figs. 1 to 4, the seat-holder consists of a frame of thin metal (by preference, cast),
oblong in cross section and of a size which permits it to drop easily into the opening
in the valve-body between the ports when the valve-bonnet is removed. Openings
somewhat larger than the port-openings are made in two sides of the frame. The
seats 44 are loosely placed within these openings, the walls of which should be bevelled
outwards. The said seats are somewhat thicker than the sides of the seat-holder and
may be made of soft metal, or of asbestos and rubber intimately mixed and hardened
by heat and pressure. They are supported by the seat-holder; their outer faces lying
against the inclined seat-faces on the valve-body, so that the openings through the
seats coincide with the ports, whilst the inner surfaces of the seats project within the
inner faces of the seat-holder in position for making close contact with the gate when
lowered.
When the bonnet of the valve-casing is secured in place, the, inwardly-projecting
lugs 7 formed thereon are so located as to rest upon the seat-holder and to prevent
the latter being lifted when the screw-spindle is rotated and the gate raised.
In Figs. 5, 6 and 7, the seats 4 4 are supported on their under sides in grooves cut
in rims 8 which are cast round the bottom of the seat-faces. The seat-holder, which,
as before described, consists of a frame oblong in cross section, has in this case the
under part cut away; the lower edges of two of its sides being so formed that they
rest upon the upper edges of the seats and hold them with their bottom edges in the
grooved rims 8 in position for the gate to be seated properly against them when
closed down. In this as in the former case, when the bonnet is removed, the holder
can be withdrawn and the seats renewed without disturbing the valve-connections;
the bonnet when in place keeping the seat-holder down.
In Figs. 8, 9 and 10, two seat-holders, each corresponding with one of the two
wider sides of the seat-holder shewn in Figs. 1, 2, 3 and 4, are employed. Thus the
seat-holders in this modification resemble thin plates, and may be rolled or stamped
to shape. They serve to support the seats, and are themselves in turn held to the
sides of the valve-body by lugs which are cast integrally therewith, as indicated
by dotted lines in Fig. 8. Or, if preferred, they may be kept in place by setting
the lower edge of each holder in a groove in the bottom of the opening in the
valve; such groove being similar to the groove in the rim shewn in Fig. 5.
It will be obvious that, instead of the seat-faces being arranged at an inclination
to one another, they may be parallel; the thickness of of each seat gradually in-
creasing from its upper to its lower part to correspond with the taper of the
gate. Under such circumstances, the seat and carrier are so shaped as to prevent
the former turning round in the latter.
Valves constructed as hereinbefore described can be produced at moderate cost,
and, when worn, may be easily renovated by simply removing the bonnet, lifting out
the seat-holder and substituting new seats. The latter being easily produced and
occupying little space, a large number may be conveniently kept on hand. As the
edges of the seats do not serve to make the joint which is to prevent leakage,
no special care in fitting these parts is required, whilst the elasticity of the seats them-
selves compensates for any inequality between the angle of the seat-faces and that of
faces of the gate. Thus the latter need not be complicated in construction in order to
insure close contact with the seats. The seat-holders are simple, and even when
roughly made answer for holding the seats in proper position.
Having now particularly described and ascertained the nature of this inven-
tion, as communicated to me by my foreign correspondent, and in what manner
the same is to performed, I claim :-
1. The improved gate-valve constructed substantially as herein described and
having removable seats and a removable seat-holder or seat-holders held down by
the bonnet.

page_text: 2: In a gate valve provided' with removable seats; mounting such seats in a
removable seat-liolder or carrier, substantially as described with reference to Figs. 1
to 4 of the accompanying drawings.
3. In a gate-valve provided with removable seats, mounting such seats in grooves
in the valve-body, the same being held down in the said grooves by means of a.
removable seat-holder or frame, substantially as described with reference to Figs. 5
to 7!
4. In a gate-valve provided with removable seats, mounting each seat in a separate
seat-holder or plate adapted for being removed together with the seat from the
valve-body, substantially as described with reference to Figs. 8 to 10.
Dated this 15th day of November 1889
G: G. M. HARDINGHAM,
191, Fleet Street, London,.E.C., Agent for the Applicant'