United States Patent (15) 3,666,236

Gachot
(45) May 30, 1972
(54) BUTTERFLY VALVE 3,356,336 12/1967 Maenaka. ...25i/306
72 Inventor: Jean Gachot, 179 Avenue de la Division 3,528,448 9/1970 Urban...... ...251 / 173 X
Lerclerc, Enghien, France 3,552,407 1/1971 Hirano. ...25 1/306X
22 Filed: Mar. 2, 1970 3,156,445 1 1/1964 Swain....................................25l/171
21 Appl. No.: 15,435 Primary Examiner-Henry T. Klinksiek
Attorney-Young & Thompson
30) Foreign Application Priority Data 57 ABSTRACT
May 7, 1969 France.................................. 6906499
May 29, 1969 France.................................. 69 17528 A butterfly valve intended for use in a piping system and com
Aug. 4, 1969 France.................................. 6926718 prising a body pierced by a duct located opposite to the two
sections of the piping system and a closure disc rotatably
(52) U.S.C..............................................................251/306 mounted on the valve body and offset laterally with respect to
5th Int. Cl............................................................ F16k 1122 its axis of rotation; the valve disc is provided at its periphery
(58) Field of Search...................25 1/306, 307, 172, 173, 171 with a convex annular bearing face, the valve body is fitted
with an annular seal which projects into the interior of the
(56 References Cited duct and said annular bearing face constitutes a seating for the
seal in the closed position. A high standard of leak-tightness in
UNITED STATES PATENTS the closed position of the valve is achieved owing to the com
2,982,305 5/1961 Grove................................ 251 / 173 X bination of the offset valve disc and of the annular projecting
3,127,182 3/1964 Wardleigh. .25 1/306X seal applied against the bearing face of the valve disc.
3,346,233 10/1967 Billson...................................251 / 172 8 Claims, 15 Drawing Figures

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 3,666,236
2
BUTTERFLY WALVE The roller bearing aforesaid preferably consists of a needle
This invention relates to an improved butterfly valve for bearing which is thus of smaller overall size.
piping systems.
In the different types of butterfly valve which are already In yet another embodiment, the valve disc is rotatably
known, the term "butterfly' designates a disc-type gate which mounted on the valve body by means of at least one bushing
provided with an internal lining of tetrafluoroethylene and
is rotatably mounted within a pipe or duct for the flow of fluids clamped in position on the valve-disc spindle.
and which is capable either of closing off said duct or of The torque is also considerably reduced and overall size is
providing a free passageway. limited to a minimum.
Leak-tightness is ensured in the closed position by means of According to another feature, the annular seal which pro
a seal or packing usually formed of rubber of of a synthesis
elastomer against which the butterfly gate or disc is applied. 10 jects into the interior of the duct is inserted in a groove of the
valve body which has substantially the same width as the seal,
In some valves of this type, the disc contains its axis of rota said seal being fitted in position by deformation.
tion and in other types is offset laterally with respect to its axis The valve is thus simplified by dispensing with the use of
of rotation.
Butterfly valves usually prove satisfactory. However, it 15 cost components for clamping the seal within its recess and the
often happens that seals or leak-tight packings have a short price of the valve is reduced accordingly.
service life, in particular when they are subjected to high pres According to yet another property, the annular seal is fitted
sures or to the action of abrasive fluids. After a certain time, by deformation in a groove of the valve body whose width is
the valve is no longer leak-tight, thereby making it necessary greater by means
than that of said seal and is retained within said groove
of a ring of complementary width which is divided
to dismantle and recondition the valve. This operation is 20 into at least two segments for the purpose of mounting said
frequently costly and is liable to put the corresponding instal ring in said groove.
lation out of service for an appreciable period of time.
An attempt has been made to construct butterfly valves theThe valve is also highly simplified by virtue of the fact that
segments serve to retain the seal within the groove in a
fitted with polytetrafluoroethylene seals. However, it has been simple and effective manner.
proved by experience that, in the closed position, deforma 25 The segments of the ring are advantageously joined together
tions of the seal take place very rapidly and result in leakage of after assembly within the groove by means of at least one weld
the valve. This situation has made it necessary to abandon the
use of polytetrafluoroethylene for this type of valve. As a con so as to couple two of their contacting extremities. When they
have been fitted in position, the segments can also be locked
sequence, it is not possible to contemplate the use of butterfly within the groove by means of at least one screw engaged in a
valves in the case of corrosive gases or liquids and this is a 30 threaded bore which is formed in the extremities of two con
major shortcoming in valves of this type which otherwise have tacting segments. Thus, the segments cannot become
remarkable properties: virtually zero torque both at the time dislodged from the groove and leak-tightness is effectively
of opening and closing up to the immediate vicinity of the maintained therein.
valve seat.
The seal is preferably formed of either pure or filled
In accordance with the invention, the butterfly valve which 35 polytetrafluoroethylene.
is intended for use in a piping system and comprises a body In another embodiment, the valve-disc seal is clamped
pierced by a duct located opposite to the two sections of the between
piping system and a closure disc rotatably mounted on the vided in an the
annular shoulder formed by a stepped recess pro
valve body both in the duct and in the adjacent
valve body and offset laterally with respect to its axis of rota face and a retaining ring having an annular flange which is
tion is characterized in that the valve disc is provided at its 40 positioned in said stepped recess.
periphery with a convex annular bearing face and that the By means of this assembly, that portion of the retaining ring
valve body is fitted with an annular seal which projects which is contact with the seal can be provided if necessary
towards the interior of the duct and said annular bearing face with an internal diameter which is smaller than in the case of
constitutes a seating for the seal in the closed position. the remainder of the duct, thereby permitting very effective
Experience has shown that a remarkably high standard of positional45 maintenance of the valve-disc seal.
leak-tightness in the closed position of the valve is achieved in According to another property, the butterfly valve in which
accordance with the invention by combining a valve disc the annular seal provided for the valve disc is mounted
which is displaced off-center with respect to its axis of rotation between an annular shoulder of the valve body and a retaining
with an annular seal which projects into the interior of the
valve duct and which is applied against the convex bearing 50 the surfacesinwhich
ring fitted said body is characterized in that at least one of
are in contact with the seal is provided with
face of the valve disc in the closed position.
As a preferable feature, the annular bearing face of the ribsPreferably, forming projections in the direction of said seal.
the ribs terminate in a sharp edge, are formed on
valve disc is constituted by a portion of sphere, the center of the opposite surfaces
which is placed at the point of intersection of the duct axis and seal-retaining ring andboth of the annular shoulder and of the
are arranged in staggered relation from
of the axis of rotation of the valve disc. A spherical profile is 55 one surface to the other. Under these conditions, excellent
more effective from the point of view of fluid-tightness. leak-tightness can be obtained, thereby permitting operation
In one embodiment which is of interest in the case of corro of the valve at high pressures and temperatures.
sive products, the material which constitutes the seal is
polytetrafluoroethylene or alternatively a mixture of beAccording to another property which can advantageously
combined with the preceding, the annular flange which sur
polytetrafluoroethylene and ground glass fibers. In point of 60 rounds the seal-retaining ring of the valve disc is provided with
fact, polytetrafluoroethylene has very good high-temperature a projecting annular seal on that face of said annular flange
strength and the mixture with glass fibers has a very low coeffi which is directed towards the adjacent pipe flange.
cient of expansion. Experience has demonstrated that the Under these conditions, the valve-disc seal can be main
combination thus achieved makes it possible to obtain leak tained by the clamping pressure which is transmitted to the
tightness over along period of time even in the case of the cor 65 retaining ring by the adjacent pipe flange. This results in sim
rosive materials mentioned above. plification both of construction and assembly and in a reduc
The seal can also advantageously be composite and com tion in capital outlay.
prise a metallic core coated with a layer of Further properties of the invention will become apparent
polytetrafluoroethylene. from the description which is given hereinafter.
In another embodiment, the disc is rotatably mounted on 70 One preferred mode of execution of the invention is illus
the valve body by means of at least one roller bearing which is trated in the accompanying drawings which are given by way
clamped in position by means of the valve-disc spindle. of non-limitative example, and in which:
The torque which is produced under high pressures both at FIG. 1 is a diametral sectional view taken along the axis of
opening and closure when the valve disc is placed in the im rotation of the valve disc and showing the butterfly valve in
mediate vicinity of its seating is thus considerably reduced. 75 the closed position;
 3
3,666,236
4.
FIG. 2 is a diametral sectional view on a smaller scale as An operating handle (not shown in the figures) is screwed
taken along line II-II of FIG. 1 and showing the valve in the onto the threaded extremity 27 of the spindle 7. Said spindle is
open position;
FIG. 3 is a detail sectional view on a larger scale and show rotatably coupled with the valve disc 6 by means of the driving
ing the seal in the closed position; square 28 which is engaged in a collar 29, said collar being
FIG. 4 is a partial sectional view on a different scale and rigidly fixed to the valve disc 6.
corresponding to FIG. 1 in an alternative embodiment in The central portion of the valve disc 6 is of greater thickness
which the seal is composite; in order to withstand the pressure of the fluid. The valve disc is
FIG. S is a sectional view on a larger scale and showing the preferably constructed of stainless steel or of a corrosion-re
composite seal which corresponds to FIG. 4; O sistant metal. The disc is provided at its periphery with a con
FIG. 6 is a diametral sectional view taken along the axis of vex annular bearing face 32 and this latter constitutes in the
rotation of the valve disc and in the closed position of a valve closed position a seating for the seal 14 which comes into con
which is fitted with needle bearings; tact with said bearingface in this position.
FIG. 7 is a radial sectional view of a valve fitted with a bush In the example herein described, the convex annular bear
ing which is provided with an internal self-lubricating lining; 15 ing face 32 is constituted by a portion of sphere S, the center
FIG. 8 is a partial radial sectional view of an alternative of which is located at the point of intersection 0 of the axis of
mode of assembly of the valve-disc seal; rotation of the valve disc 6 and of the axis of the duct S. The
FIGS. 9 and 10 are respectively a radial sectional view and a relative positions of the seal 14 and of the bearing face 32 are
corresponding partial plan view of another mode of assembly such that the frusto-conical surface of the seal 14 and the
of the valve-disc seal; bearing face 32 are tangent in the closed position (as shown in
FIG. 11 is a partial plan view of an alternative form of the FIG.3).
preceding mode of assembly; The operation and advantages of the valve herein described
FIG. 12 is a partial half-sectional view of another alternative are as follows.
form; Assuming that the valve disc 6 is initially in the open posi
FIG. 13 is a large-scale diametral sectional view taken along 25 tion as shown in FIG. 2 and that the fluid is circulating in the
the axis of rotation of the valve disc and showing that portion direction of the arrow F, changeover to the closed position is
of the valve body which comprises the seal and the adjacent effected by rotating the operating handle in the direction of
retaining ring; the arrow G. The valve disc 6 which is actuated by means of
FEG. 14 is a partial view which is similar to the preceding 30 the square 28 is moved into the position shown in chain-dotted
but on a larger scale and showing an improved construction; lines and corresponding to FIG. 1. Motion of the disc is ar
FIG. 15 is a view which is similar to FIG. 13 showing a rested by means of a stop which is not shown in the drawings.
preferred construction of the retaining ring and of the as The spherical bearing face 32 which is centered on the point
sociated seals. of intersection 0 of the axis of the duct 5 and of the axis of
In the example which is described with reference to FIGS. 1 35 rotation of the valve disc 6 describes in rotational motion of
to 3, the butterfly valve 1 is mounted between flanges 2 of a the disc 6 a sphere which is tangent to the frusto-conical sur
piping system 3. This valve comprises a body 4 through which face of the seal 14.
is pierced a cylindrical duct 5 located in oppositely facing rela During the rotation of the valve disc 6, the bearing face 32
tion to the two sections of the piping system 3 and a disc 6 remains in tangential contact with said frusto-conical surface
which is rotatably mounted on spindles 7 and 8, said spindles 40 of the seal 14 over all or part of its periphery and complete
being located in the line of extension of each other. The valve closure is thus effected without difficulty.
disc 6 is offset laterally relative to the spindles 7 and 8. in the closed position, the pressure of the fluid which is ex
. The valve body 4 has two parallel end-faces 9 which are erted in the direction of the arrow G tends to thrust the seal 14
clamped between the pipe flanges 2 by means of tie bolts (not towards the large-diameter portion of the bearing surface 32,
shown in the drawings) which are passed through bores 11 45 thereby enhancing leak-tightness. Thus, when the seal 14 is
formed in said pipe flanges.
There is placed on each face 9 an annular packing ring 12 of formed of polytetrafluoroethylene, said seal does not exhibit
polytetrafluoroethylene which is fitted in a groove 13 and pro any tendency to creep at high pressure. Since the seal projects
jects to the exterior in order to ensure transverse leak to a distance of only 1 or 2 millimeters, it does not tend to be
tightness. 50
displaced as a result of a substantial annular surface area.
An annular seal 14 which is concentric with the duct 5 is The incorporation of ground glass fibers which retain an
fitted between a shouldered portion 15 of the valve body 4 and elongated structure after grinding has the surprising effect of
a retaining ring 16 which is attached to said valve body 4 by reducing the coefficient of expansion of the mixture to a very
means of countersunk-head screws 17. The seal forms within substantial proportion of the order of two-thirds. When
the interior of the duct 5 a slight projection of the order of 1 to 55 fabricated from this mixture, the seal 14 thus has outstanding
2 mm. In the example herein described, the orifice of the an creep strength, especially in the case of high temperatures and
nular seal 14 has a frusto-conical surface. high pressures. The seal also exhibits good resistance to abra
The seal 14 is formed, for example, of sive fluids.
polytetrafluoroethylene or alternatively and preferably of a In practice, very satisfactory results are obtained when the
mixture of polytetrafluoroethylene with ground glass fibers, 60 frusto-conical surface of the seal 14 has a semivertical angle a
the percentage of incorporated fiber being within the range of which is substantially within the range of 6 to 10 and which is
12 to 18 percent. This corresponds to a material which is inert preferably equal to 8.
with respect to aggressive agents and which is suitable for use It has proved in practice that, in the movement of closure
at high temperatures (of approximately 280 C.). under high operating pressures, the torque which tends to
The spindles 7 and 8 which are fitted within bores 18 of the 65 result in closure of the duct is insignificant up to a position
valve body 4 are each provided with an annular boss 19. which is very close to full closure. In the case of opening, the
On the side nearest the duct 5, each boss 19 is abuttingly ap torque is of high value in the vicinity of the position cor
plied by means of a friction washer 21 against an annular responding to initial unseating and then very rapidly becomes
shoulder 22 of the bore 18. insignificant.
On the side which is remote from the duct 5, each boss 19 is 70 In the case of low pressures, leak-tightness remains satisfac
abuttingly applied by means of a guide sleeve 23 against an tory when the fluid circulates in the direction opposite to the
end plate 24, the spacing of this latter with respect to the valve arrow G.
body 4 being adjusted by means of clamping screws 25. Finally, the butterfly valve 1 constitutes a novel element in
An annular seal 26 is interposed between each boss 19 and the family of different pipe couplings which are described in
the corresponding sleeve 23 in order to ensure leak-tightness. 75 U.S. Pat. No. 3,409,268 patented Nov. 5, 1968.
 S
3,666,236
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The valve can in fact be mounted between two flanges 2 of a clamps this latter in position. Each bushing 45 which is fitted
piping system 3 when the diameter of the valve body 4 is in one of the bores 18 is provided with an internal lining 46 of
smaller on the one hand than the space which is provided polytetrafluoroethylene, this material being endowed with
between two consecutive clamping tie bolts and which con self-lubricating properties.
stitutes a passageway for the valve body 4 and is greater on the By reason of the very low coefficient of friction of the spin
other hand than the space formed between two other consecu dles 7 and 8 against the linings 46, the torque in the vicinity of
tive tie bolts which constitute a position stop for the valve the position of closure of the valve disc 6 is very low and
body 4.
As shown in FIGS. 4 and 5, the seal 14 can be replaced by a remains of the same order of magnitude as in the previous em
bodiment.
composite seal 33 constituted by a metallic core covered with 10
a thin coating of polytetrafluoroethylene. In another embodiment which is shown in FIG. 8, the annu
The external portion of the composite seal 33 has an undu lar seal 14 which projects into the interior of the duct is in
lated or wavy cross section 34, this portion being clamped at serted in a groove 50 of the valve body 4 which has substan
the time of assembly between the annular shoulder 15 and the tially the same width as the seal, said seal being fitted in posi
tion by deformation.
retaining ring 16. In the internal portion which comes into 15 Experience has shown that, in the case of ordinary operat
contact with the bearing face 32 of the valve disc 6 in the ing pressures and average valve diameters (of the order of 10
closed position, the seal 33 has a cross section which cor cm), the seal 14 which is thus inserted in the groove 50 ex
responds to that of said bearing face and constitutes a valve hibits very satisfactory resistance.
seat 35. In the example illustrated, the seat 35 is spherical and 20 The assembly of the seal 14 is thus simplified. The capital
concentric relative to the point 0 with the bearing face 32. The cost of the valve is appreciably reduced by dispensing with the
operation is similar to that of the first example. retaining ring 16 and the screws 17 which are shown in FIG. 6.
Leak-tightness within the duct 5 is ensured by the contact In another embodiment which is shown in FIGS. 9 and 10,
which is made between the bearing face 32 and the coating of the annular seal 14 is fitted in a groove 51 of the valve body 4,
polytetrafluoroethylene which is provided on the valve seat 25 the width of said groove being greater than that of said seal.
35.
The seal 14 is fitted in the groove 51 by deformation.
Leak-tightness between the valve body 4 and the retaining A rigid ring 52, the width of which is substantially comple
ring 16 is ensured by the wavy corrugations 34 coated with mentary to that of the seal 14, is also mounted in the groove
polytetrafluoroethylene. Clamping of the wavy portion within 51 so that the seal 14 is secured within its recess when the ring
its recess by means of the screws 17 ensures that the valve seat 30 has been fitted in position.
35 is applied against the bearing face 32 as a result of elastic For the purpose of assembly, the ring 52 is divided into at
deformation of the seal 33.
least two segments 52a, 52b which are placed end-to-end
The composite seal 33 has particularly good resistance to within the groove 51 and the ring 52 is thus reconstituted after
high pressures and high temperatures which can attain 300°C. assembly.
in the particular embodiment described with reference to 35 The relative clamping of the segments 52a, 52b and of the
FIG. 6, the butterfly valve 1 is mounted between the flanges 2 seal 14 within the groove 51 has the effect of maintaining the
of a piping system 3 as in the case of FIG. 1. A cylindrical duct segments in end-to-end relation without any attendant danger
5 is pierced in the valve body 4 and a valve disc 6 is rotatably of being dislodged. The seal 14 is also securely fixed in posi
mounted on the spindles 7 and 8 which are located in the line tlOn.
of extension of each other. The valve disc 6 is offset laterally 40 As was the case with the previous embodiment, this im
relative to the spindles 7 and 8. An annular seal 14 which is provement facilitates the assembly of the seal 14 and results in
concentric with the duct 5 is fitted in the valve body 4 and low capital cost of the valve 1. The seal 14 can easily be fitted
held in position by means of a retaining ring 16. The seating of in the groove 51 and the width of this latter makes it possible
the seal is constituted in the closed position by the bearing to reduce the deformation which is necessary.
face 32 of the valve disc 6. The spindles 7 and 8 which are 45 In another improvement which is shown in FIGS. 9 and 10,
mounted in the bores 18 of the valve body 4 each have an an the segments of the ring are joined to each other after fitting in
nular boss 19 which is abuttingly applied by means of a fric the groove 51 by means of at least one weld which is applied
tion washer 21 against an annular shoulder of the bore 18 and along the line of contact 53, for example, so that two con
are each fitted with an O-ring seal 26 in order to ensure leak 50 tiguous extremities of said segments are thus rigidly coupled
tightness. together.
Each spindle 7 and 8 is rotatably mounted in the valve body The segments are thus in no way liable to escape from the
4 by means of a bearing 40a, 40b which is housed within the groove and the seal 14 is effectively retained therein.
corresponding bore 18. In the example illustrated, the In another embodiment which is shown in FIG. 11, an inter
bearings 40a, 40b are fitted with needle rollers 41a, 41b. 55 nally threaded bore 54 is formed in the contiguous extremities
Each bearing 40a, 40b which is placed between inter of two segments 52a, 52b. A screw 55 is engaged in the
mediate washers 42 and 43 is held in position by means of an threaded bore 54, the diameter of said screw being chosen so
end plate 24 which is adjustably spaced with respect to the that it tends to separate the two extremities of the segments
valve body 4 by means of clamping screws 25. 52a, 52b and thus take up any play which exists between all
This mode of assembly produces the following technical ef 60 the segments.
fect.
When the valve is in service and the disc is very nearly in the
It is thus ensured that the segments cannot escape from the
groove 51 and that the seal 14 cannot be dislodged.
closed position, experience has shown that the torque which is In all the forms of construction which are described in the
necessary in order to open or close the valve as thus designed foregoing, the seal 14 is advantageously made of
is reduced to a surprising extent. 65 polytetrafluoroethylene (PTFE), this product being employed
Thus, in the case of a valve 200 mm in diameter which is either in the pure state or combined with fillers.
subjected to a pressure of 20 to 25 bars, the torque which at In yet another alternative form which is shown in FIG. 12,
tains 25 to 30 kgm in the case of a sleeve assembly is reduced the valve comprises a stainless steel casing 61 which complete
in the case under consideration to 3 to 4 kgm. ly isolates the retainer cage of the roller bearing 40 from the
The valve can therefore be operated smoothly in the im 70 point of view of fluid-tightness. To this end, the casing 61
mediate vicinity of the closed position whereas in the case of comprises a cup 62 which is in contact with the spindle 7 by
conventional butterfly valves, it is precisely in this position means of an O-ring seal 63. The cup 62 is closed by means of
that the efforts are considerable, which is a major drawback. an annular cover 64 fitted with two O-ring seals 65, 66 which
In another form of construction which is shown in FIG. 7, complete the intended arrangements for ensuring fluid-tight
each spindle 7 and 8 is rotatably mounted in a bushing 45 and 75 closure. The casing 61 can advantageously be filled with
 7
3,666,236
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grease, thereby ensuring excellent protection of the roller 1. In a butterfly valve for use in a piping system and which
bearing 40. comprises a body pierced by a duct to be located between two
In the embodiment of FIG. 13, a part of the valve body sections of the piping system and a closure disc rotatably
which is described in FIG. is shown at 4, an annular recess mounted on the valve body and offset laterally with respect to
150 being machined in said body so as to form a shoulder 15, its axis of rotation, wherein the valve disc is provided at its
the annular seal 14 which is provided for the spherical bearing periphery with an annular bearing surface and wherein the
face 32 of the valve disc 6 being applied against said shoulder. valve body has an annular seal which projects into the interior
The machined recess 150 is surrounded by a second annular of the duct for engagement with said annular bearing surface,
recess 153 formed in that face of the valve body 4 which is when said disc is in the closed position; the improvement in
directed towards the pipe flange 2. A complementary annular 10 which the valve-disc seal is clamped between an annular
flange 154 is formed on the retaining ring 16 and is intended shoulder formed by a stepped recess in the valve body both in
to be positioned within the annular recess 153. Attachment of the duct and in the adjacent face and a retaining ring having
the elbowed member which is formed by the retaining ring 16 an annular flange which is positioned in said stepped recess,
and the annular flange 154 is carried out by means of screws said stepped recess being L-shaped in cross section, said
17 as in FIG. 1. By means of this mode of assembly, which can retaining ring being L-shaped in cross section, said annular
be carried out very easily and rapidly, the seal 14 can also be flange having a projecting annular seal on that face of said an
very readily replaced. nular flange which is directed towards the adjacent pipe sec
tion.
As seen in FIGS. 13-15, the ring 16 is L-shaped in cross sec
tion, and the recesses 150 and 153 together define a recess 20 said2. first-mentioned
A valve as claimed in claim 1, in which the material of
seal is polytetrafluoroethylene.
that is L-shaped in cross section.
The annular shoulder 15 is provided with ribs 151 which are 3. A valve as claimed in claim 1, in which the material of
said first-mentioned seal is al mixture of
directed towards the seal 14. At least one complementary rib polytetrafluoroethylene and glass fibers,
152 which is also directed towards the seal 14 is formed on the
bearing surface 16a of the retaining ring 16. The ribs 151 and 4. A valve as claimed in claim 1, at least one of said annular
152 are preferably of prismatic shape and each have a sharp 25 shoulder and retaining ring having thereon ribs forming pro
edge which is intended to compress the seal 14. It is also jections that indent the first-mentioned seal.
preferably ensured that the ribs 151 and 152 are arranged in 5. A valve as claimed in claim 4, in which said ribs terminate
in sharp edges.
staggered relation. 6. A valve as claimed in claim 4, said ribs being formed both
Under these conditions, when the retaining ring 16 is 30 on said annular shoulder and on said retaining ring.
pressed towards the shouldered portion 15, said ring ac 7. In a butterfly valve for use in a piping system and which
cordingly flattens the seal 14 by compression. The ribs 151, comprises a body pierced by a duct to be located between two
152 deform said seal elastically and concentric sealing zones sections of the piping system and a closure disc rotatably
are thus obtained.
mounted on the valve body and offset laterally with respect to
In accordance with another property which can ad 35 its axis of rotation, wherein the valve disc is provided at its
vantageously be combined with the preceding, the recess 153 periphery with an annular bearing surface and wherein the
of the valve body 4 is dimensioned so that the annular flange valve body has an annular seal which projects into the interior
154 which is formed laterally around the retaining ring 16 can of the duct for engagement with said annular bearing surface,
be mounted with slight play (as shown in FIG. 14). Moreover, when said disc is in the closed position; the improvement in
said annular flange 154 is adapted to carry the projecting 40 which the valve body has a double-stepped annular recess at
packing ring 12 which is inserted in the free face of said one end of said duct, said double-stepped recess comprising
flange. two radial shoulders and two peripheral faces, said annular
Under these conditions, the seals 12 and 14 can be fitted seal resting on the inner of said shoulders, and tightening
very simply and rapidly. It is thus only necessary after posi means for tightening said seal against said inner shoulder, said
tioning the valve body 4 to engage the annular flanges 154 45 tightening means comprising a ring comprising a tubular part
within the machined recesses 153 on each side, this operation slidable within the inner of said peripheral faces, the end of
being performed without either tools or adjustment. said tubular part being in contact with said seal, said ring hav
When the valve body 4 is clamped between the adjacent ing an outwardly extending annular flange on the end thereof
pipe flanges, the seals 12 and 14 are compressed to a sufficient opposite the end that contacts said seal, the last-named flange
extent to ensure leak-tightness. 50 being housed at least partially between the outer peripheral
In all cases, it is found when operating the valve that the face and the outer radial shoulder of said recess, the face of
clamping force exerted between the conical seal and the said last-mentioned flange opposite said outer radial shoulder
spherical bearing face of the valve disc is of a very low order. having a seal fitted therein and projecting therebeyond to con
Nevertheless, the valve remains leak-tight under very high tact and seal with an adjacent pipe section.
pressures. Thus, a valve having a diameter of 50 mm is capable 55 8. A valve as claimed in claim 7, at least one of the first
of withstanding without leakage a pressure of the order of 40 mentioned end of said tubular part and said inner radial
kg/cm, while nevertheless permitting substantial mobility of shoulder having ribs thereon forming projections that indent
the valve disc, which is a surprising result. the first-mentioned seal.
What I claim is:
60

65

70

75
 UNITED STATES PATENT OFFICE
CERTIFICATE OF CORRECTION
Patent No. 3,666,236 Dated May 30, 1972
Inventor(s) Jean Gachot
It is certified that error appears in the above-identified patent
and that said Letters Patent are hereby corrected as shown below:
On the cover sheet 3O) heading "Foreign
Application Priority Data" change "May 7, 1969" to
-- March 7, 1969 -- .
Signed and sealed this 7th day of November 1972,

(SEAL)
Attest:
EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK
Attesting Officer COmmissioner of Patents

ORM PO-1050 (10-69) Usco MMs to c 6037 6-peg