EP0000682B1 - Plug valve of the through-flow type - Google Patents

Description

The present invention relates to a rotary valve with full passage. In the usual technique, full-flow rotary valves have a spherical, cylindrical or conical rotation, having a round lumen. The seals are mounted on the valve body and rub on the turn while it is rotating.

It follows that the choice of materials for the seals and the turn obeys special constraints if it is desired that the tightness of the valve, when it is formed, remains after a certain number of operations. If the fluid passing through the valve is corrosive, it can happen that in conditions such that no material can resist satisfactorily both corrosion by the fluid and abrasion due to friction of the turning on the joint, and we are forced to fall back on valves of another type, more complicated, therefore more expensive.

In fact, so-called valves with parallel seats, with two covers, are known, in which a movable assembly carries two covers which come to bear on seals to ensure closure. To move from the closed position to the fully open position, the lids undergo two successive movements, first a movement in a direction parallel to that of the pipe carrying the valve, so as to separate the lids from their seats, then a movement in a direction perpendicular to the previous one so as to completely clear the passage through the valve. Such embodiments make it possible to obtain a long-lasting seal, because the cover is not subjected to any friction against its seat and its seal. However, they require relatively complicated mechanical devices.

The object of the present invention is to provide a valve which combines the simplicity of a rotary valve with sealing and duration characteristics which have so far been obtained only with valves with parallel seats, with two lids.

It has already been proposed to combine the advantages of the rotary valve with those of the movable gate valve.

For example, US Patent 2,531,759 describes a ball valve in which the turn carries the cover and drives it in its rotation: when approaching the closed position, the edge of the cover abuts on the edge of the seal, and a cam forming part of the turn then pushes the seal against this seal. Such an arrangement can lead to rapid deterioration of the seal, because the cover does not move perpendicular to its plane.

Patent FR 1,593,350 describes a valve of similar type, but in which the cam, which pushes the cover, is not part of the turn, but is part of an intermediate piece carried by the turn with an elastic means interposed. In addition, a special stop is provided to stop the seal outside the area which constitutes the seal. Such an arrangement is likely to spare the seal and increase its duration, but this gain is limited because the movement of the cover at the time of closure is still a pivoting around a point located near the plane seal.

In patent FR 2,053,455, a cover is connected to the turn by a link system. The head of a link is guided by a groove and a stop of the body so as to impart to the seal a movement perpendicular to its plane at the time of closing. Such an arrangement is more rational from the kinematic point of view, but it is hardly simpler than that of a valve of the type with parallel seats.

Thus, it appears that so far a satisfactory compromise has not been obtained between the simplicity of the rotary joint and the rational arrangement of the valve with parallel seats.

The valve according to the present invention has characteristics in common with each of the two types of valves, since it comprises both a full-flow turn and lids moving perpendicular to their seats.

More specifically, the invention relates to a rotary valve with full passage, as defined in claim 1. Preferably the zone of action of the intermediate piece on the cover is located in the vicinity of the axis of the latter. .

Thus, the valve according to the invention can allow rational movement of the cover at the time of closing, thanks to the fact that the cover can be guided in the desired direction, and in particular have a rectilinear movement, perpendicular to its plane, which, as we saw above, is not possible when it is in abutment at this time, because its only possible movement is then a pivoting around the abutment point, which is in its plane or close to this plane, and which is only possible in an approximate manner when it is carried by connecting rods, despite the complication of the latter system.

The guide of the cover can be obtained in a simple way by providing that the turn carries the cover through a housing forming part of said turn and in which a stud carried by the internal face of the cover slides freely in the direction of the axis of the cover.

In this case, it is preferable that the cover further comprises a peripheral rib which cooperates with two circular guides carried respectively by the bottom of the body and by the cap in order to limit the amplitude of the pivoting of the cover coming from the play of the stud in its housing.

According to a variant, the turn carries the cover by means of holding and driving stirrups which penetrate into a peripheral groove of the cover with sufficient play to allow its movement under the action of the intermediate piece. In this case, it avoids having a part sliding in a nozzle, which can be troublesome in certain particular cases of temperature or nature of the bodies, but at the cost of a complication of the shape of the turn.

According to another variant, the cover is carried directly by the intermediate piece while being able to move relative to this piece along the axis of the cover.

In this case, it is possible to simplify as much as possible the shape of the turning, bulky piece, the complication being transferred to the intermediate piece, which is of smaller dimensions.

In all cases, according to a particularly advantageous arrangement, the means for holding the cover are provided to allow the cover to rotate about its axis while rolling on the body during the rotation of the turn, and the body or the cap. of the valve comprises a circular guide which cooperates with the edge of the cover to drive it in rotation when the turn is itself in rotation, that is to say that if the cover has a stud penetrating a housing, this stud has a circular section and the same axis as the cover, and if the cover is held by stirrups penetrating a groove, the latter has the shape of a complete circle of the same axis as the operculum. This arrangement allows self-running of the seals.

Preferably, an elastic means exerts on the intermediate piece a force tending to maintain it in the rest position, this force being overcome by that exerted by the stop for the passage into the active position, and advantageously the valve comprises an additional spring intended to facilitate the recoil of the cover towards the turn when opening. This is avoided if any risk of unwanted friction of the cover against the valve body.

• Fig. 1 est une vue en demi-coupe verticale d'une vanne selon l'invention en position fermée;
• Fig. 2 est une vue en coupe horizontale partielle de la même vanne également en position fermée;
• Fig. 3 est un schéma en perspective montrant la relation des pièces mobiles;
• Fig. 4 est une vue en coupe horizontale partielle d'une variante de la vanne des figures précédentes.

The invention will be described in more detail with the aid of the figures, which relate to a non-limiting example of embodiment according to the invention and among which:

• Fig. 1 is a view in vertical half-section of a valve according to the invention in the closed position;
• Fig. 2 is a partial horizontal sectional view of the same valve also in the closed position;
• Fig. 3 is a perspective diagram showing the relationship of the moving parts;
• Fig. 4 is a partial horizontal sectional view of a variant of the valve of the preceding figures.

The valve body 1 comprises a cap 2, a bottom 3 and two end pieces 4, to be welded on pipes.

The turning 5, of generally tubular shape, carries at its upper part an operating rod 6 which crosses the cap 2 of the body, and, at its lower part, a pivot 7, coaxial with the operating rod, and which penetrates into a housing 8 of the bottom 3 of the body. It supports two lids 10 provided, towards their periphery, with a seal 11 intended to cooperate with a corresponding seal 12 secured to the body. The turn comprises a housing 14 in which a stud 13 carried by the internal face of the cover slides freely in the axial direction of the cover, which ensures the drive of the cover by the turn during the rotation of that -this. The cover further comprises a peripheral rib 15 which cooperates with a circular guide 16, carried by the bottom 3 of the body, and a similar guide 17, carried by the cap 2. The role of the guides 16, 17 is to limit the amplitude of the upward or downward pivoting of the cover in a play of the stud 13 in its housing 14 during the rotary movement of the turn, and of preventing a defective engagement of the cover during closing.

Stops 18, carried by the turn, have the same role as regards the pivoting of the cover forwards or backwards in the direction of rotation of the turn. The intermediate piece 19 has the general shape of a corner, having a central recess. More specifically, it comprises a body 20 extended by two wings 21 which are connected at their opposite end to the body 20 by a cross member 22. The internal face 23 of the wings 21, that is to say that which faces towards the center of the turn 5, is oblique, so that the width of the wings 21 decreases away from the body 20; this internal face 23 constitutes a cam surface which comes to bear on an oblique boss 24 integral with the turn 5. The external face of the end of the wings 21 and of the cross-member 22 consists of a bearing surface 25 which comes into contact, during closing, with the internal face of the cover 10 in the central region of this cover.

A spring 26, working under compression, is placed between the wings 21 and bears, on the one hand, on the body 20 of the intermediate piece, and, on the other hand, on a boss 27 of the turn 5. This boss is crossed by the housing 14 of the stud 13, and its upper part enters between the wings 21 and constitutes a stop for the crosspiece 22, thus limiting the stroke of the spring 26.

The valve body 1 carries a boss 28 on which the end 29 of the body 20 of the intermediate piece comes to bear at the end of the rotary movement of the turn 5 in the closing direction. The surface of the end 29 of the body 20 which comes into contact with the stop 28 is rounded so as to allow a slight pivoting in a direction perpendicular to the axis of turning rotation.

The operation of the valve is as follows: in the open position, the turn 5 is aligned with the nozzles 4 so as to provide the fluid with a passage of uniform section, the lids 10 are substantially in a vertical plane parallel to the passage of the fluid, the intermediate piece 19 is in the rest position, that is to say it is pushed by the spring 26 which separates it from the boss 27, is held in position by the support of the cross-member 22 on the same boss 27 As a result, the intermediate piece 19 exerts no pressure on the cover 10. If it is desired to move to the closed position, the rotary 5 is actuated using the rod 6, so as to do so rotate on its vertical axis. The lids 10 are driven in the movement by the stud 13, their relative position relative to the turn 5 being maintained, with a slight play, thanks to the guides 16, 17 and to the stops 18. The intermediate piece 19 is driven with the turn 5 When the end of the closing movement is reached, the end 29 of the intermediate piece comes into contact with the stop 28 which stops it. As the turning 5 continues its movement, the oblique boss 24 acts on the cam surface 23 and causes the intermediate piece to tilt which, by means of the bearing surface 25, moves the cover 10 away from the turning 5 and brings its lining 11 to cooperate with the lining 12, carried by the body, to ensure sealing.

For opening, the same movements take place in reverse.

Note the extreme simplicity of the mechanism which, as shown in Figure 3, includes only three moving parts in the case of a single lid, and five moving parts in the case of two lids.

Note also the extreme ease of disassembly, the moving parts having no screwing, keying or the like.

There are also two factors favorable to obtaining an excellent seal: on the one hand, the self-running of the linings thanks to the rotation of the cover when it rolls on one of the circular guides 16 , 17, and, on the other hand, the equal distribution of the pressure on the linings thanks to the position of the contact zone of the bearing surface 25 in the central zone of the cover.

Of course, the device is likely to present variants. For example, in one of them, the drive and guide assembly of the cover, comprising the pin 13, the guides 16, 17 and the stops 18, is replaced by another assembly, illustrated by the Figure 4, and comprises a cover 10 whose edge has a peripheral groove 32 and stirrups 30 for holding and driving, screwed onto supports 31 forming part of the turn 5 and which penetrate into this peripheral groove 32. The play of the stirrups 30 in the groove 32 is calculated to allow a suitable movement of the cover 10 under the action of the intermediate piece 19 as well as the rotation of the cover on itself. To this end, the groove 32 is provided over the entire periphery of the cover.

This variant, illustrated in FIG. 4, has the essential advantage of giving the cover a better grip thanks to a greater flexibility due to the peripheral groove, the operation and the arrangement between the cover and the seat remaining similar to the embodiment described with the aid of FIGS. 1 to 3. In another variant, an additional spring facilitates the retraction of the cover towards the turn when opening.

In all cases, the invention provides a direct passage at the same time as a perfect and lasting seal which is particularly appreciable in the handling of corrosive and / or dangerous gases or liquids.

Claims (9)

1. Valve having a rotary member and an unrestricted passageway, comprising a body (1) which may be connected on two opposite sides to two conduits having the same axis, a rotary member (5) movable inside the said body by rotation about an axis perpendicular to the common axis of the conduits, the said rotary member being traversed by a port of section close to that of the conduits and rotatable from an open position where the port has substantially the same axis as the conduits to a closed position where the axis of the port makes with the axis of the conduits an approximately right angle, the body and the rotary member being provided with means for ensuring fluidtightness of the valve in the closed position, the rotary member carrying at least one plus (10) movable in a direction perpendicular to the axis of the rotation and an intermediate part (19) placed between the rotary member and the plug and movable relative to the rotary member, the body having an abutment (28) against which the intermediate part bears at the end of rotation, approaching the closed position, but does not limit the rotation of the rotary part which causes by the relative movement between these parts the change of the relative position of the plug from a rest position to an active position where the intermediate part exerts on the plug a force tending to move it away from the rotary member to ensure fluidtightness in the closed position, characterized in that the intermediate part comprises a slide which is slidable between the plug and the rotary member, which bears against the abutment during rotation of the rotary member and which has a cam surface for cooperation with a cam surface provided on the rotary member.

2. Valve according to claim 1, characterized in that the rotary member (5) carries the plug (10) by the medium of a housing (14) forming part of the said rotary member (13) and in which a teat (13) carried by the inner face of the plug slides freely in the direction of the axis of the plug.

3. Valve according to claim 2, characterized in that the plug further comprises a peripheral rib (15) which cooperates with two circular guides (16, 17) carried respectively by the bottom of the body and the top in order to limit the magnitude of pivoting of the plug resulting from the play of the teat in its housing.

4. Valve according to claim 1, characterized in that the rotary member carries the plug by the medium of holding and driving stirrup members (30) which penetrate into a peripheral groove (32) of the plug with sufficient play to permit its displacement under the action of the intermediate part.

5. Valve according to claim 1, characterized in that the plug (10) is carried directly by the intermediate part (19) while being displaceable relative to that part along the axis of the plug.

6. Valve according to one of claims 1 to 5, characterized in that the means for holding the plug are provided for permitting the plug to rotate about its axis by rolling on the body during rotation of the rotary member, and in that the body or the top of the valve comprises a circular guide (16, 17) which cooperates with the edge of the plug for driving it for rotation when the rotary member is itself in rotation.

7. Valve according to one of claims 1 to 6, characterized in that the zone of action of the intermediate part on the plug is in the vicinity of the axis of this latter.

8. Valve according to one of claims 1 to 7, characterized in that the elastic means (26) exerts on the intermediate part (19) a force tending to maintain it in the rest position, this force being overcome by that exerted by the abutment (28) for changing to the active position.

9. Valve according to one claims 1 to 8, characterized in that it comprises an additional' spring adapted to facilitate the retraction of the plug (10) towards the rotary member (5) during opening.

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