FR2509010A1 - DEVICE FOR CONTROLLING THE FLOW OF A FLUID HAVING EASILY REMOVABLE LININGS - Google Patents

Abstract

The invention relates to a device for controlling the flow of a fluid, like a valve, comprising in a body 11, a valve 24, placed at the end of a rod 25 movable under the action of a gearmotor 96 supported. BY AN ARCADE 62, THE TIGHTNESS OF THE PASSAGE OF THE ROD IN THE CAP 27 BEING PROVIDED BY GASKETS. SO AS TO ALLOW THE EASY EXTRACTION OF THE SEALS WITHOUT REMOVING THE ARCADE, THE GEAR MOTOR IS CONNECTED TO THE ROD BY THE INTERMEDIATE OF TWO PINIONS 91, 76, GEARING THE PINION 76 BEING SCREWED ON THE ROD 75 AND BEING EASILY REMOVABLE.

Description

DEVICE FOR CONTROLLING THE FLOW OF A FLUID A
EASILY REMOVABLE TRIMS
The invention relates to a device for controlling the flow of a fluid, such as a tap, with easily removable seals.

A known tap comprises a body with a through passage in which the fluid to be controlled circulates, a shutter element of the passage placed at the end of a movable rod under the action of a drive means mounted at the other end of the rod. and carried by an arcade secured to the body, the rod passing through a cap screwed into the body, the sealing of the bushing being ensured by fittings held in place by a packing press.

To change the linings, in particular when they are worn, the stuffing box is detached from the cap and it is made to slide along the rod until it stops on the yoke, thus freeing an extraction passage for the worn linings and of fitting new linings around the rod by deformation of these thanks to the radial slot that they present.

However, this operation is often difficult and sometimes impossible because the space thus freed between the stuffing box and the cap remains limited, and cannot be enlarged without lengthening the height of the arch, and therefore the space and the tap weight.

 I1 is thus sometimes necessary, to replace the linings, to deposit the yoke itself after having dismantled the drive means, and until now this removal is always essential when it is desired to use annular unsplit linings of which the efficiency is much higher than that of the split linings which can only be placed around the rod by sliding them along the latter.

However, this removal is long, and its duration is sometimes prohibitive, especially when the tap is located in a polluted room, for example radioactive.

The object of the invention is therefore to provide a device for controlling the flow rate of a fluid, the structure of which is such that it allows the linings to be easily changed, in particular annular linings which are not split, without however requiring the removal of the means of or training.

The device for controlling the flow of a fluid according to the invention, which comprises a body with a through passage in which the fluid to be controlled circulates, and a member for closing the passage placed at the end of a rod movable under the action a drive means, the rod passing through a cap, the sealing of the bushing being ensured by fittings, is characterized in that the rod is connected to the drive means by an easily removable means for transmitting movement.

The rapid removal of the single transmission means then allows the linings to be extracted by moving them along the rod.

When the rod passes through the yoke carrying the drive means, the invention provides that the orifice for the passage of the rod in the yoke has dimensions sufficient to allow the extraction of the linings.

The upper face of the arch, which is no longer necessary to dismantle, constitutes a seat, centered on the rod, making it possible to easily fix extraction tools and fitting of linings.

Preferably, the rod has a threaded part engaged in a threaded through hole of a first pinion meshing with a second pinion connected to the drive means, the first pinion being rotatably mounted on the yoke in an easily removable manner.

The rod and the output axis of the drive means being thus offset, it then suffices, to gain access to the linings, to remove the first pinion after having detached the stuffing box from the cap.

In addition, when the control device is a tap whose rod is inclined relative to the through passage, the eccentric position of the drive means relative to the rod allows to obtain a more compact structure and whose center of gravity is closer to the body; the mechanical torques exerted on the means for connecting the valve body to the pipeline on which the latter is mounted, and due to the lever arm of the drive means, are thus reduced, which is of great interest when the pipeline is susceptible to be subjected to vibrations or to seismic stresses.

In one embodiment, the passage orifice formed in the arch is of sufficient size to allow the flange of the stuffing box to pass.

In another embodiment, only the gland and the linings can pass through the orifice, the flange of the stuffing box then consisting of a crown surrounding the rod and two removable half-rings housed in the crown around the rod to serve as a stop for the gland.

To change the linings, after having deposited the first pinion, the crown of the gland is moved aside, which allows the two half-rings to be extracted, the gland and then the worn linings being then slid along the rod successively through the crown then of the opening of passage of the rod in the arch.

The new linings are then threaded onto the rod, and reassembly of the gland, the stuffing box and the first pinion can take place.

Advantageously, the rotation of the rod is prohibited by an arm fixed at one of its ends on the rod and having at its other end a ring sliding on a fixed finger.

This precisely machined finger ensures exact guidance of the rod; which was not the case in the bar guidance system based on a raw foundry arch.

Preferably, the arm is fixed to the free end of the rod and the finger, located outside the arch, is carried by the latter.

This arrangement provides better access to the stuffing box, for example to tighten the latter during operation of the control means.

In addition, the position of the arm used as a means of indicating that of the shutter element is more easily exploitable when it is outside the yoke, for example the possible installation of limit switches is particularly easy.

In an embodiment of the control device which is advantageous for its compactness, the cap carries on either side of the rod elastic means situated below the flange of the gland, capable of attracting the latter towards the body.

It is thus possible to ensure a constant and well calibrated tightening of the linings in service, and the axial dimension of the stuffing box is reduced by the length of the elastic means which, in a previously known tap, acted directly on the linings along the rod, at - above the gland.

The invention will be better understood with the aid of the description given below by way of example only with reference to the drawing in which - FIG. 1 is a view in axial section of a valve according to the invention, - Figure 2 is an exterior elevation of this valve, and - Figure 3 is a sectional view similar to Figure 1, but on a larger scale, of a portion of the valve according to the invention.

The tap shown comprises (fig. 1) a body 11 having a through passage 12 whose end pieces 13, 14 are welded to a pipe (not shown), a chamber 15 of generally cylindrical shape, of axis XX 'inclined by 450 by relative to the axis of the passage 12, communicating by its lower end 16 (in FIG. 3) with the passage 12 and ending at its upper open end by a threaded part 17 formed in the barrel of the body 11.

The end 16 accommodates with play a cylindrical jacket 18 whose lower annular end abuts on a corresponding shoulder 19 of the body 11 surrounding the passage 12, with the interposition of a seal 20, under the action of a nut 21 externally threaded and screwed in part 17.

The lower part of the jacket, pierced laterally at 22 to ensure the continuity of the passage 12, forms an internal seat 23 for a cylindrical valve 24 with spherical sealing surface fixed to the lower end of a rod 25, and sliding in shirt 18.

The threaded cylindrical lower part 26 of a cap 27 is screwed into the outlet 17 of the chamber 15, and has a through hole 28 in which the rod 25 is engaged, the hole 28 widening successively at 29 and 31 so in housing a guide ring 32 and fittings 33.

The latter, which surround the rod 25 and which are constituted by an alternating stack of rings of expanded graphite and graphitized asbestos, are held in place by a sleeve-shaped gland 34 surrounding the rod 25 and penetrating into the hole 31 under the action of a flange 35 in the form of a crown extending around the rod 25, and itself having two through holes 36 diametrically opposite with respect thereto (only the hole 361 being visible in FIGS. 1 and 3, the part of the stuffing box illustrated on the right of the axis XX 'representing a section at 900 of that illustrated on the left of this axis).

The internal surface of the central orifice 37 of the flange 35 has a recess 38 facing the body 11 serving as a stop for an external shoulder 39 presented by two half-rings 411, 412 rammed in the orifice 37, surrounding the rod 25 , and on the spherical lower surface 42 which bears the upper end of the gland.

In the holes 36 are engaged bolts 43 (only the bolt 431 being shown in the drawing) whose heads 44 are housed in openings of holes 36 opening opposite the body 11, and whose tails 45 carry, by via nuts 46, sleeves 47 with lower flanges 48 each supporting a stack of Belleville washers 49 forming a spring.

The upper end of the two stacks 49 is supported on a crown 51 which is pierced by two through holes 521, 522 of the tails 45 and of the sleeves 47, which surround the cylindrical upper part 54 in the form of a neck of the hat 27, and which is held at the neck by abutment on a ring 55 housed in a groove 56 external to the neck 54.

The sealing of the cap 27 relative to the body It is ensured by mutual welding of the periphery of two lips 57, 58 presented by the cap and by the body.

The cap 27 also includes a passage 59 normally closed by a plug and allowing an external pressurized fluid to reach the underside of the lining 33 in contact with the guide ring 32 when it is desired to drive the trim from their housing. 31, and a passage 61 connected to a pipe and emerging in the middle of the stack of linings to collect the fluid capable of slipping between the linings and the rod 25 or the neck 54.

An arch 62 is bolted to the body 11, concentrically with the cap 27, and comprises two arms 63, 64 opposite with respect to the axis XX 'and meeting at their parts remote from the body 11 in two bent trays 65,66, the tray 65 being located (in FIG. 1) below the tray 66, the trays each forming two flat supports 67,68; 69.70, the supports 68, 70; 67, 69 being respectively perpendicular to the axis XX 'and to an axis YY' making an angle of 450 with the previous one, and has four circular through holes 71, 72; 73, 74 aligned two by two along the axes XX 'and YY'.

The upper part of the threaded rod 25 is engaged in the holes 71 and 72 with the interposition of a bushing 75 internally threaded and carrying on its external surface, between the supports 68 and 70, a first pinion 76 with toothed crown 77 making with the axis XX 'an angle of 450 whose apex is located on this axis between the pinion and the body 11 of the valve.

The pinion 76 is keyed to the socket 75, which prevents it from rotating relative to the latter around the axis XX ', and is supported by its lower annular surface 79 on a shoulder 81 of the socket 75.

The sleeve 75 rotates on two roller bearings 821, 822 which are locked axially by a nut 83 screwed on the upper part of the sleeve 75, and are housed in a shoe 84 centered at 72 on the yoke and bolted to the support 70
The upper end of the rod 25, above the sleeve 75, carries an arm 85 fixed by a pin 86, the end of the arm carrying a ring 87 sliding to slide on a machined finger 88, parallel to the axis
XX ', and fixed by screwing at 89 on the support 70.

A second pinion 91 meshes with the pin 76 and is carried by a shaft 92 of axis YY ', one end 93 of which is engaged with the interposition of a sealing ring 94 in the hole 73 and the other end constitutes the plate coupling of a gearmotor 96 with reducer 96 carried by a support 97 bolted to the support 69 and centered in the bore 74, ball bearings 98 being interposed between the shaft 92 and the support 97. Grease channels 99, 101 are provided for bearings 98 and 82.

A means of manual actuation of the shaft 92, such as a flywheel 102 (FIG. 2) is provided on the side of the gearmotor 96 directed towards the axis XX '.

The operation of the tap which has just been described is as follows
The geared motor 96 rotates the second pinion 91 which leads the first pinion 76, which, thanks to the interposition of the rollers 82, rotates around the axis XX 'in the shoe 84 which maintains it relative to the yoke 62 , and the arm 85 guided by the finger 88 preventing the rod 25 from turning on itself, the latter is driven by the internal thread of the sleeve supporting the pinion 76 to move axially, either at the approach of the body 11 or at the distance, according to the direction of rotation of the motor and at a speed which depends on the gear ratio chosen for the pinions and the geared motor 96.

It is thus possible to control the position of the valve 24 relative to the seat 23.

When the valve is in the low position, the flow of fluid in the passage 12 is interrupted by cooperation of the valve 24 and of the seat 23, and when the valve 24 is brought back to the high position, the sealing of the passage of the rod 25 in the cap 27 is perfect by cooperation of a conical counter-valve 102 (FIG. 3) located at the upper part of valve 24 with a corresponding counter-seat 103 formed at the lower part of cap 27.

When, for example after a certain operating time of the tap, it becomes necessary to change the linings 33, after having interrupted by the means not shown the flow of the fluid in the passage 12, the valve is placed in the high position, the ranges sealing 102 and 103 being in contact, the linings are released by removing the bolts 44 and they are ejected by introduction of the high pressure fluid through the orifice 59, taking advantage of the support provided by the valve maintained in position by its means d 'training.

We can then unscrew the bolts holding the shoe 84 on the support 70, or place the arm 85, and rotate the pinion 76 on itself, by hand or, at the start for example, by actuating the gearmotor 96, the thread of the rod 25 and of the sleeve 75 being such that the latter is raised with the pinion 76 along the rod 25 which remains immobile, causing the shoe 84 to move.

The extraction of the first pinion, made possible without dismantling the second pinion 91 by the inclination adopted for the cooperating faces of these pinions being complete, the flange 35 of the stuffing box is slid along the rod 25 towards the plate 68; when the holes 71 and 72 are of sufficient size to allow the flange to pass, the latter is extracted as well as the gland 34 and the fittings -; when, on the contrary, the hole 72 is not large enough to allow the flange 35 to pass, which is the case for the tap shown, the half-rings 41 are removed, the gland and the linings can then be slid along the rod 25 first in the hole 37 presented by the flange 35 then in the holes 71 and 72.

Reassembly takes place in reverse to disassembly, after which the optimal adjustment of the pressure exerted by the gland 34 on the linings 33 can be easily obtained by providing that the sleeves 47 are flush with the upper part of the crown 51 when the optimal compression of the fittings 33 is reached by tightening effect of the nuts 46 on the shanks 45.

As can be seen in FIG. 2, the center of gravity CG of the valve is relatively close to the body 11, and is practically centered with respect to the nozzles 13 and 14, which would not be the case if the gearmotor 96 was mounted on the axis XX ', at the end of the rod 25, or if the washers 42 were placed above the gland 34.

Claims (9)

1- Device for controlling the flow of a fluid, comprising a body (11) with through passage (12) in which the fluid to be controlled circulates, a shutter element (24) of the passage placed at the end of a rod ( 25) movable under the action of a drive means (95, 96, 91), the rod passing through a bonnet (27), the sealing of the bushing being ensured by fittings (33), characterized in that the rod is connected to the drive means by an easily removable movement transmission means (76), the removal of the transmission means making it possible to extract the linings by moving them along the rod. 2- A device for controlling the flow of a fluid according to claim 1, the rod passing through an arch (62) carrying the drive means, characterized in that the passage orifice (71, 72) of the rod in the arcade has sufficient dimensions to allow the extraction of the linings. 3- A device for controlling the flow of a fluid according to claim 2, characterized in that the rod comprises a threaded part engaged in a threaded through hole of a first pinion (76) meshing with a second pinion (91) connected to the drive means (95, 96), which makes it possible to offset the rod and the output axis of the drive means, the first pinion being mounted in rotation on the yoke in an easily removable manner. 4- A device for controlling the flow of a fluid according to claim 2 or claim 3, characterized in that the pass orifice formed in the arch is of sufficient size to allow the flange (35) of the stuffing box to pass through. . 5- A device for controlling the flow of a fluid according to claim 2 or claim 3, characterized in that only the gland (34) and the linings can pass through the orifice, the flange (35) of the stuffing box being consisting of a crown surrounding the rod and removable means (41) housed in the crown around the rod to serve as a stop for the gland. 6- Control device according to claim 5, characterized in that said removable means (40) are constituted by two half-rings. 7- A device for controlling the flow of a fluid according to any one of the preceding claims, characterized in that the rod is guided linearly by an arm (85) fixed at one of its ends on the rod and having at its other end a ring (87) sliding on a fixed finger (88), which allows exact guidance of the rod. 8- A device for controlling the flow of a fluid according to claim 7, comprising an arch, characterized in that the arm is fixed to the free end of the rod and the finger, located outside the arch is carried by the latter, allowing easy access to the stuffing box. 9- A device for controlling the flow of a fluid according to any one of the preceding claims, characterized in that to improve its compactness, the cap -port on either side of the rod below the gland (34) elastic means (42) able to attract the flange (35) of the stuffing box towards the body.