GB2225624A

GB2225624A - Removable discharge sleeve in a disc valve

Info

Publication number: GB2225624A
Application number: GB8924365A
Authority: GB
Inventors: Fred Woodson Hendrick; Bobby Leon Brooks
Original assignee: Automatic Control Components Inc
Current assignee: Automatic Control Components Inc
Priority date: 1988-10-31
Filing date: 1989-10-30
Publication date: 1990-06-06
Also published as: FR2638503A1; DE3935460A1; GB8924365D0; NO894324L; IT1237632B; CA1318218C; IT8922109A0; IT8922109A1; NO894324D0

Description

-I- PATENTS ACT 1977 Agents' Reference: P613OGB-H/JCC/ac

DESCRIPTION OF INVENTION

Title: "Removable discharge sleeve in a disk valve" THIS INVENTION relates to a valve having relatively movable disc members with respective fluid openings which can be brought into and out of fluid conducting alignment for discharging fluid to a discharge port, and, more particularly, to a valve having a stationary disc and a rotatable disc mounted in a valve housing in a face-to-face confronting relationship in a pathway for fluid in a valve body, the discs each being provided with at least one orifice or opening to control the flow of fluid through the valve by the size of the holes in the disc as well as the degree of alignment between the holes in the disc. Such a valve is herein referred to as a disc valve "of the kind sPecifiedll.

In a known disc valve of the kind specified, angular movement of one disc relative to the other in the valve body is accomplished by turning a handle situated outside of the valve body but coupled to produce rotation of the rotatable disc, whereby the rotatable disc can be moved from a fully open position wherein the hole or holes in one disc align with the hole or holes in the other disc for providing maximum flow through the valve to a fully closed position wherein the hole or holes in the respective discs are misaligned, the holes or holes in each disc being blocked by solid portions of the confronting discs.

Valves of this type are particularly useful for controlling the flow of fluids from oil and gas wells and the like. Such a valve is used to control the rate of flow of well production fluids that may contain abrasive con- tainments such as sand particles. Such fluid when entering the valve can be under extreme pressure of the order of, for example, 3000 PSI. The openings in the discs are of a smaller cross-sectional area than either an upstream entry chamber or a downstream discharge chamber that are formed in a valve body. The flow restriction formed by the opening in the discs cause an acceleration of the fluid passing through the openings. The increase to the velocity of the fluid emerging from the opening in the downstream disc enters a discharge chamber which has a cross- sectional area that is greater than the cross-sectional area of the openings in the downstream disc. Because of the construction of the discharge chamber, particularly when formed by a renewable sleeve in the valve body, a large pressure drop in the fluid passing through the sleeve is created. The effect is to reduce the capacity of the valve, and, because of the construction of the removable sleeve, abrupt changes to the configuration of the opening in the sleeve produce turbulence in the fluid, particularly at the outlet of the valve which is unprotected by the renewable sleeve.

In the known form of valves of the type under discussion, the outlet is defined by an oblong transverse configuration immediately downstream of the downstream disc. The oblong configuration is a result of the need to provide openings to receive retainer pins which are used to anchor the disc in the valve body. The area of the oblong configuration is reduced by the thickness of the sleeve when such a protective sleeve is required for the outlet chamber. The reduced oblong area of the disc in turn limits the maximum size of the disc that can be used with the renewable sleeve as compared with, for example, the size of the oblong outlet chamber when a removable sleeve is not used. The smaller volume for conducting fluid in the sleeve creates a larger pressure drop in the fluid passing through the sleeve, and thus reduces the capacity of the valve.

Moreover, in the known form of valves using renewable sleeves at the outlet chamber, the sleeve is fixed to the valve body by an adhesive, such as epoxy cement, which also is relied upon to prevent the flow of fluid between the sleeve and the valve body. When it is necessary to replace the sleeve, the valve body must be heated to a temperature sufficient to soften the epoxy so that the sleeve can be removed. Typically, it is known to heat a valve body to over 2501F in order to soften effectively the epoxy for replacement of the sleeve.

It is an object of the invention to provide a disc valve in which the above-noted disadvantages of known disc valves can be avoided.

According to the present invention there is provided a valve including a valve body having an internal cavity with an inlet and outlet for fluid, a rotator spool seated for rotational movement in the cavity of the valve body at a spaced location upstream of the fluid outlet, the rotor spool having a passageway in continuous fluid receiving communication with the inlet for directing fluid to the outlet of the valve body, an upstream disc locked to rotate with the rotor spool in the cavity of the valve body downstream of the rotor spool, the upstream disc having a fluid passageway for conducting fluid from the fluid passageway of the rotor spool, a downstream disc arranged in a face-to-face and confronting relation with the upstream disc in the cavity of the valve body, the downstream disc having a fluid passageway for conducting fluid from the opening in the upstream disc, a removable tubular insert interlocked with the downstream disc while supported by the valve body for conducting fluid from the opening in the downstream disc to the outlet, the tubular insert having a circular transverse cross-section with interlocking supports protruding in the circular configuration oll' the insert at the downstream side of the disc, means for interlocking the downstream disc member with the tubular insert, and means for rotating the rotatory spool while seated in the cavity of the valve body to bring the passageway in the upstream disc and the passageway in the downstream disc into and out of fluid conducting relationship.

The renewable tubular insert may have an end wall with a passageway therein to meter the flow of liquid discharged from the tubular insert to the outlet of the valve body. Preferably, an annular sealing element is provided between the downstream disc and the valve body, and the rotor spool is provided with a seal restraint surface having an annular configuration and supported by the rotor spool, which restraint surface limits the travel for the seal in the event of, for example, a reverse fluid flow or pressure condition, but is just clear o the annular seal in normal operation of the valve to avoid frictional contact with the annular seal. The restraint surface thus serves to hold the seal captive between the disc and the valve body.

An embodiment of the present invention is described below by way of example with reference to the accompanying drawings in which:

FIGURE 1 is an exploded isometric view of a valve embodying features of the present invention; FIGURE 2 is a sectional view showing the assembly of parts illustrated in Figure 1 forming the valve of the present invention; FIGURE 3 is a transverse sectional view of a sleeve member at the discharge chamber of the valve shown in Figures 1 and 2; 11 FIGURE 4 is a front plan view of the sleeve member shown in Figure 3; FIGURE 5 is a rear plan view of the sleeve shown in Figure 3; FIGURE 6 is a sectional view taken along lines VI-VI of Figure 4; FIGURE 7 is an enlarged view in section to illustrate the relationship between a downstream disc and the sleeve shown in Figures 3 to 6; FIGURE 8 is a sectional view similar to Figure 7 and illustrating an embodiment of sleeve member to achieve a predetermined pressure drop at the discharge of the valve; FIGURE 9 is an end view taken along lines IX-IX of Figure 8, and FIGURE 10 is an enlarged view similar to Figure 2, but illustrating a preferred embodiment of the rotor spool for the valve of the present invention.

In Figures 1 and 2 there is illustrated a valve which includes a valve body made up of body parts 10 and 11 provided with flanges 12 and 13, respectively. Flange 13 has drilled and tapped holes to receive end portions of bolts 14 that are passed through drilled holes in flange 12 to secure the body parts of the valve together. By this configuration, access can be gained to the interior of the valve for assembly of internal components therein. Valve body part 10 includes an inlet portion formed by an enlarged hub 15 having internal threads formed in the hub for receiving a corresponding threaded end portion of a pipe. Similarly, valve body part 11 is provided with an enlarged hub 16, having an internally threaded portion which can receive the threaded end of a pipe for the discharge of fluid from the valve.

As can be best seen in Figure 2, the inlet formed by hub 15 extends to a cylindrical cavity 17 in body part 10. A rotor spool 18 is positioned in the cylindrical cavity 17, and 0-rings 19 and 20 mounted in grooves formed in the rotor spool near the terminal ends thereof form a fluid tight seal with the valve body to prevent the passage of fluid between the rotor spool and the valve body. Fluid supplied to the valve from the inlet can pass through a passageway 21 in the rotor spool 18. In this embodiment the passageway 21 extends in the longitudinal direction along the length of the spool. At the end of the spool 18 which faces toward the valve outlet, the cavity 17 exten ds beyond the end of the spool and a cavity 17A is f ormed as an extension of the cavity 17 in body part 11. A floating disc 22 is drivingly interlocked with the rotor spool 18 by pins 23 which extend into openings in the disc 22 and into openings in the end face of rotor spool 18. The spool 18 can be rotated by a control handle 24, which is provided with a threaded end portion that can pass through an annular slot 25 in valve body part 10, where the threaded end portion of handle 24 engages in a threaded opening 26 formed in the spool 18. It will be observed that the slot 25 is situated in the valve body between the support sites for the two 0-rings. By the the rotating the spool through operation of the handle, spool rotates about an axis corresponding to longitudinal axis of the spool. The rotation of the spool 18 imparts a rotary movement to the disc 22 such that in the embodiment shown in Figures 1 and 2, openings 27 and 28 of disc 22 can be moved into and out of alignment or registration with corresponding openings 29 and 30 in a disc 31. The disc 31 is held in a stationary manner relative to the housing part 11 by anchor pins 32, which, as best shown in Figure 1, are received in drilled openings formed in the disc 31 and other openings aligned therewith and formed in a -I- replaceable sleeve 33.

The sleeve 33 as shown in Figures 3 - 6, has an annular discharge section 35 and has, upstream of section 35, a generally truncated conical section 36. The section 36, as can be best seen in Figure 4, is provided with protruding sections 37 that extend into the conical configuration of the section at the entrance end of the sleeve. These protruding sections form sites where holes 32A are formed to hold anchor pins 32. The transverse area of the sleeve along its length is maximized for capacity to carry the largest possible volume of fluid discharged from the valve. The form of the interior of the sleeve is such as to minimise the pressure drop in the valve. Thus, the taper provided by the truncated conical portion of the sleeve reduces turbulence and the tubular outlet of annular discharge section 35 of sleeve 33 is designed to match the outlet of the valve body to prevent unwanted turbulence in the unprotected or unlined portion of the valve body. As can be seen from Figures 3, 5, and 6, on the outside of the sleeve 33 there are provided anchor lugs 40 at diametrically opposite sides of the sleeve. The anchor lugs are protrusions on the outside surface of the sleeve which interlock with recesses, shown in Figure 2 formed in the sleeve seating surface of valve body at the discharge outlet side of the disc 31. The sleeve of the present invention is designed to avoid and eliminate the need for epoxy or other adhesive to hold the sleeve to the valve body. The sleeve 33 is retained against the seating surface in the valve body by pressure of the fluid exerted on the valve body at the inlet end. It can be seen from Figure 2 that when the valve spool is in a position for delivering fluid to the discharge portion, there is a pressure drop across the valve due to the throttling of fluid flow by the flow passage through the spool and by the openings in the valve discs. When the valve is in a position to block fluid flow there is, of course, an even greater pressure drop across the valve discs. In either case, the pressure drop applies a force sufficient to hold the discs in their confronting face-toface relation, and, at the same time, to press the sleeve 33 against the valve body with sufficient force to maintain the sleeve in a seated relationship with the valve body.

As best shown in Figure 7, in order to prevent unwanted flow of fluid between the sleeve and the valve housing, and to prevent flow of fluid about the outer periphery of the disc 31, there is provided an 0-ring 42 which is seated in a gap formed between the outer circumferential face surface of disc 31 and the wall of the valve body part 11. The relationship of the 0-ring is such that the 0-ring is seated at the parting line between the sleeve 33 and the valve seating surface of the body part 11.

In a preferred embodiment of the present invention, as shown in Figure 10, the 0-ring 42 is retained in close proximity to its desired sealing site by a cylindrical extension 43 to the rotor spool 18. The cylindrical section 43 is provided with a relatively thin wall section having at its terminal end a thickened restraint section 44 which is an enlargement on the outside diameter of section 43. The end face of restraint section 44 is sufficiently broad to entrap the 0-ring 42 and prevent unwanted displacement of the 0-ring away from its intended sealing site. The extension of the rotor spool serves further to facilitate assembly of the valve by holding the discs 22 and 31 in their confronting face-to-face relationship with the upstream disc 22 being locked by the pins 23 to the rotor spool. In the normal operation of the valve, the inlet pressure is higher than the outlet pressure, thus allowing fluid to flow from the inlet to the outlet. The flow is controlled by the relative positions of the openings 27, 28 and 29, 30 in the two discs. The 0-ring 42 is held in place by friction and differential pressure urging the 0-ring towards the low pressure side of the valve. In the past, 3 sudden changes in the downstream conditions for the fluid, such as a valve closing or a sudden drop in flow conditions will cause a hydraulic hammer, resulting in a momentary pressure pulse in the outlet that is higher than the fluid pressure in the inlet. This pressure pulse can be large enough, in some instances, to unseat the seal provided by the O- ring 42. Once the O-ring sealing has been disrupted, the normal operation of the valve will allow a fluid flow, although small, between the disc sidewalls and the cavity formed in the valve body. The material used to form the valve body normally cannot withstand the abrasive cutting action caused by the by-pass flow of fluid and thus, irreparable damage will occur. In other instances, a deliberate back-flush of fluid is caused to occur for any one of numerous reasons. Hence, there is established a flow of fluid through a valve in a reverse direction, i.e. outlet to inlet, the result is the same as the result produced by a hydraulic hammer. To correct thus, the extension to the rotor spool, as described above, avoids the unseating of the sealing O-ring 42. The restraint established by the end wall 44 can be provided by dimensioning the thin wall section 43 to prevent rubbing or friction during adjustment of the valve for normal operation and to form a limit of travel for the O-ring. Thus, the axial dimension of the thin wall section 4.)' is such that, in normal operation of the valve, there is a slight clearance between the end wall 44 and the O-ring 42 so that the end wall 44 does not normally rub on the O-ring. If a reverse flow or pressure change in the reverse direction occurs, the sealing O-ring 42 moves only as far as allowed by the restraint provided by the wall 44 extended from the rotor spool. The extent of movement is such that the O-ring 42 is retained in place between the disc and the valve body so that when normal pressure flow conditions are restored to the valve, the 0ring immediately assumes its proper sealing relationship. Provision of an extension to the rotor spool offers the further advantage of making it possible for the 0--ring 42 to t be wedged tightly in place, uniformly about the periphery of the disc, without the need for special implements. In the past when an O-ring corresponding to O-ring 42 was placed in its sealing site, it was common to wedge the O-ring through the use of a pointed blade, such as a screw driver. Good uniform seating of the O-ring could not be achieved by such means. However, with the provision of the extension to the spool, an automatic continuous seating of the O-ring is provided. It is to be understood, however, that the retention function of the cylindrical extension of the spool can be achieved by providing, for example, an extension to the valve body arranged to protrude into the opening formed in the housing part 11 for receiving the discs.

In Figures 8 and 9 there is illustrated a further embodiment of the discharge sleeve, in which the sleeve 33A is provided with an end wall 45 at the discharge end of the tubular portion 35A of the sleeve. The end wall 45 is provided with an opening 46 to conduct fluid from the sleeve to the discharge outlet opening. Opening 46 is dimensioned so as to achieve a predetermined pressure drop in the valve. This fixed pressure drop is in addition to a variable pressure drop that occurs through the flow control operation of the discs. The size of the opening 46 will be selected according to the specific application to which the valve has been assigned. Thus, the opening 46 will be sized and drilled according to predetermined requirements. In this way, it is possible to produce two pressure drops within the valve and thereby reduce or eliminate cavitation in the valve. By situating the openings in the end wall 45 at the geometrical centre of the end wall, any turbulence or cavitation is isolated in the centre of the outlet which avoids adverse effects caused by cavitation at the walls of the outlet.

While the present invention has been described in accordance with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiment for performing the same functions of the present invention without deviating therefrom. Therefore, the present invention should not be limited to any single embodiment but rather construed in breadth and scope in accordance with the recitation of the appended claims.

Claims

1. A valve including the combination of: a valve body having an internal cavity with an inlet and outlet for fluid; a rotator spool seated for rotational movement in the cavity of said valve body at a spaced location upstream of the fluid outlet, said rotator spool having a passageway in continuous fluid receiving communication with the inlet for directing fluid to the outlet of the valve body; an upstream disk locked to rotate with said rotator spool in the cavity of said valve body downstream of said rotator spool, said upstream disk having a fluid passageway for conducting fluid from the fluid passageway of said rotator spool; a downstream disk arranged in a face-to-face and confronting relation with said upstream disk in the cavity of said valve body, said downstream disk having a fluid passageway for conducting fluid from the opening in said upstream disk; a tubular insert interlocked with said downstream disk while supported by said valve body for conducting fluid from the opening in the downstream disk to said outlet, said tubular insert having a circular transverse cross section with interlocking supports protruding in the circular configuration of the insert at the downstream disk; means for interlocking said downstream disk member with said tubular insert; and means for rotating said rotator spool while seated in the cavity of the valve body to bring the passageway in the upstream disk and passageway in the downstream disk into and out of fluid conducting relationship.

2. The valve according to claim 1 wherein said tubular insert includes a cylindrical fluid discharge portion and upstream thereof a truncated conical portion for receiving fluid from said downstream disk, said truncated portion having protruding lug sections extending outwardly therefrom and forming anchor sites for said means for interlocking said tubular insert with said valve body.

3. The valve according to claim 1 wherein said means for interlocking said tubular insert with said valve body comprise means for preventing rotation of the tubular insert relative to a mating surface formed on said valve body.

4. The valve according to claim 1 wherein said tubular insert includes an end wall at a fluid discharge end thereof, said end wall having an opening therein for conducting fluid to said outlet.

5. The valve according to claim 4 wherein said opening has a predetermined size for achieving a predetermined pressure drop in a fluid conducted by the valve.

X i i

6. The valve according to claim 1 further including means for preventing flow of fluid between said tubular insert and said valve body.

7. The valve according to claim 6 wherein said means for preventing flow of fluid includes an 0-ring.

8. The valve according to claim 7 further including means for preventing dislodgment of said 0-ring from a seated sealing condition between the valve body and the tubular insert.

9. The valve according to claim 8, wherein said means for preventing dislodgment includes a wall section projecting from said rotor spool.

10. The valve according to claim 1 wherein said valve body has an internal cavity extending to the inlet for fluid, said cavity having a opening sufficient to support and form a fluid i:ight seal with said rotor spool.

11. The valve according to claim 1 wherein said tubular insert has a circular transverse cross section and said means for interlocking said downstream disk with said tubular insert comprise means protruding into the circular transverse cross section of the tubular insert and into the downstream disk.

12. A valve including the combination of:

valve body having an internal cavity with an inlet and outlet for fluid; rotator spool seated for rotational movement in the cavity of said valve body at a spaced location upstream of the fluid outlet, said rotator spool having a passageway in A continuous fluid receiving communication with the inlet for directing fluid to the outlet of the valve body; an upstream disk locked to rotate with said rotator spool in the cavity of said valve body downstream of said rotator spool, said upstream disk having a fluid passageway for conducting fluid from the fluid passageway of said rotator spool; a downstream disk arranged in a face-to-face and confronting relation with said upstream disk in the cavity of said valve body, said downstream disk having a fluid passageway for conducting fluid from the fluid passageway in said upstream disk, a tubular insert interlocked with said downstream while supported in said valve body for conducting fluid fror fluid passageway in the downstream disk to said outlet, said -hereof, insert including an end wall at a fluid discharge end t said end wall having an opening of predetermined size therein for achieving a predetermined pressure drop in a fluid conducted by said tubular insert to said outlet; means for interlocking said tubular insert with said valve body; means for interlocking said downstream disk with said tubular insert; and disk the 1 % i means for rotating said rotator spool while said rotator spool is seated in the cavity of the valve body to bring the passageway in the upstream disk and the passageway in the downstream disk into and out of fluid conducting relationship.

13. A valve including the combination of:

valve body having an internal cavity with an inlet and outlet for fluid; rotator spool seated for rotational movement in the cavity of said valve body at a spaced location upstream of the fluid outlet, said rotator spool having a passageway in continuous fluid receiving communication with the inlet for directing fluid to the outlet of the valve body; an upstream disk locked to rotate with said rotator spool in the cavity of said valve body downstream of said rotator spool, said upstream disk having a fluid passageway for conducting fluid from the fluid passageway of said rotator spool; a downstream disk arranged in a face-to-face and confronting relation with said upstream disk in the cavity of said valve body, said downstream disk having a fluid passageway for conducting fluid from the fluid passageway in said upstream disk; a tubular insert interlocked with said downstream disk while supported in said valve body for conducting fluid form the fluid passageway in the downstream disk to said outlet; means for interlocking said tubular insert with said valve body; 1 means for interlocking said downstream disk with said tubular insert; said tubular insert having a circular transverse cross section and said means for interlocking said downstream disk with said tubular insert comprise means projecting into protrusions formed in a truncated conical portion of the circular transverse cross section of the tubular insert and into the downstream disk; and means for rotating said rotator spool while said rotator spool is seated in the cavity of the valve body to bring the passageway in the upstream disk and the passageway in the downstream disk into and out of fluid conducting relationship.

14. A valve including the com-bination of: a valve body having an internal cavity with an inlet and outlet for fluid; an upstream disk rotatably supported in the cavity of said valve body and having a fluid passageway for conducting fluid; means for rotating said upstream disc; a downstream disk arranged in a face-to-face and confronting relation with said upstream disk in the cavity of said valve body, said downstream disk having a fluid passageway for conducting fluid from the fluid passageway in said upstream disk; a tubular insert interlocked with said downstream disk while supported in said valve body for conducting fluid from the fluid passageway in the downstream disk to said outlet; means for interlocking said tubular insert with said valve body; and means for interlocking said downstream disk with said tubular insert; said tubular insert including a truncated conical portion and having a circular transverse cross section, said tubular insert further including means protruding into said truncated conical portion for receiving said means for interlocking said downstream disk with said tubular insert, said means for interlocking said downstream disk with said tubular insert comprising means projecting into said means for receiving and into said downstream disk.

15. The valve according to claim 14 wherein said tubular insert further includes an end wall at a fluid discharge end thereof, said end wall having an opening of predetermined size therein for achieving a predetermined pressure drop in a fluid conducted by said tubular insert to said outlet.

16. A valve substantially as hereinbefore described and as shown in the accompanying drawing.

17. Any novel feature or combination of features described herein.

Published 1990 at The Patent Office. State House. 66 71 High Holborn. LcndonWC1R4TF,Further copies Maybeobtainedfron-, The Fatent Office Sales Branch, St Mary Cray. Orpington. Kent BR5 3RD. Printed by Multiplex techniques ltd. St Mary Cray. Kent. Cor. 187,