CN110848408A - Compensable sealing plug valve - Google Patents

Abstract

The invention discloses a compensable sealing plug valve, comprising a valve body, a valve cover and a valve stem. The valve body is provided with a valve cavity which is communicated with an inlet end and a discharge end, and the valve stem is located in the valve cavity. One end of the valve body is provided with a plug body, a bushing is provided between the plug body and the valve body, the cross-sectional area of the end of the plug body away from the valve stem is smaller than the cross-sectional area of the end close to the valve stem, and the valve stem is far away from the plug body. One end of the valve stem is keyed with a drive device that can drive the valve stem to rotate, one end of the valve stem outside the valve body is provided with an adjusting pressure plate, and one side of the adjusting pressure plate is provided with a first fastener, the first fastener One end of the fastener mates with the bonnet threads. The invention has the following advantages and effects: the plug valve has a compensatory sealing structure, which can solve the problem of sealing failure caused by wear between the plug and the bushing after long-term use, thereby prolonging the service life of the plug valve.

Description

A Compensable Sealed Plug Valve

technical field

The invention relates to a plug valve, in particular to a compensable sealing plug valve.

Background technique

The plug valve is a closed or plunger-shaped rotary valve, which can be opened or closed by rotating 90 degrees to connect or separate the channel opening on the valve plug and the channel opening on the valve body. The shape of its valve plug can be cylindrical or conical, and the channel is trapezoidal.

The Chinese patent with the publication number CN204961883U discloses a plug valve, which includes a valve body, a plug and a valve cover. The valve body is provided with a valve cavity, the plug is located in the valve cavity, and a plug rod is connected to the top of the plug. The valve body is made of alloy steel, the cock is made of ceramics, the cock and the valve body are cylindrically matched, the contact surface between the cock and the valve body is provided with a rotating bushing, the rotating bushing The top of the sleeve is also provided with a sealing ring, the top of the sealing ring is provided with a gland, the gland presses the sealing ring on the top of the cock, and the cock is provided with a connecting channel, and the size of the inlet and outlet of the connecting channel is the same as that of the valve. The size of the lumen channel is matched. In the prior art, the use of the rotating bushing realizes the sealing cooperation between the cock and the valve body, and effectively prevents the leakage of the medium.

However, during the long-term opening and closing process of the cock, the sealing surface on the bushing in contact with the cock is prone to wear, which leads to the failure of the seal between the cock and the bushing, thereby causing leakage, which needs to be improved.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a compensable sealing plug valve, which has a compensating sealing structure, which can solve the problem of sealing failure caused by wear between the plug and the bushing after long-term use, thereby prolonging the service life of the plug valve. service life.

The above-mentioned technical purpose of the present invention is achieved through the following technical solutions: a compensable sealing plug valve, comprising a valve body, a valve cover and a valve stem, and the valve body is internally provided with a valve communicating with the inlet end and the outlet end Valve cavity, one end of the valve stem in the valve cavity is provided with a plug body, a bushing is provided between the plug body and the valve body, and the cross-sectional area of the end of the plug body away from the valve stem is smaller than the cross-sectional area of the end close to the valve stem One end of the valve stem away from the plug body is keyed with a drive device that can drive the valve stem to rotate, one end of the valve stem outside the valve body is provided with an adjustment pressure plate, and one side of the adjustment pressure plate is provided with a first A fastener, one end of the first fastener is screwed with the valve cover.

The present invention is further provided as follows: one end of the valve rod outside the valve body is provided with a limit groove, a split ring is arranged in the limit groove, and one end of the split ring passes out of the limit groove, and the adjustment The pressure plate is sleeved on the valve stem, and the bottom of the adjustment pressure plate abuts against the split ring exposed outside the limit groove.

The present invention is further provided as follows: a sealing packing assembly is arranged between the valve stem and the valve cover, and the sealing packing assembly includes a second gasket, a packing gasket, a first gasket and a packing pressure sleeve arranged in sequence from bottom to top, The side of the second gasket away from the packing gasket abuts against the valve cover.

The present invention is further provided as follows: the valve cover is provided with a compensation mechanism that can drive the sealing packing assembly to compress to increase the sealing performance between the valve cover and the valve stem, and the compensation mechanism includes a compensation mechanism that is opposed to the upper end face of the packing pressure sleeve One side of the packing pressure plate is provided with a second fastener, and one end of the second fastener is threaded with the valve cover.

A further arrangement of the present invention is that: the plug body is arranged in the shape of a truncated cone or a cone.

The present invention is further provided as follows: one end of the valve rod outside the valve body is fixedly connected with a sealing compensation pressure plate, the bottom of the sealing compensation pressure plate is in contact with the upper end surface of the sealing packing assembly, and one side of the sealing compensation pressure plate is penetrated with a sealing compensation pressure plate. A third fastener, one end of the third fastener is screwed with the valve cover.

The present invention is further provided as follows: the plug body, the valve cover and the valve body together form a gap for the plug body to rotate.

The present invention is further provided as follows: it also includes a safety mechanism, the safety mechanism includes a telescopic tube assembly, one end of the telescopic tube assembly is fixedly connected to the valve stem, and the other end of the telescopic tube assembly is fixedly connected to the sealing compensation pressure plate , the telescopic tube assembly has a cavity inside, and the cavity is built with a number of expansion beads that will expand in contact with the volume of the medium; one side of the sealing compensation pressure plate is provided with a conduit, and one end of the conduit is connected to the telescopic tube assembly. The inner cavity is communicated, and the other end of the conduit is communicated with the gap through the valve cover.

The present invention is further provided as follows: the telescopic tube assembly includes a telescopic sleeve seat fixedly connected with the valve rod, the inner wall of the telescopic sleeve seat is horizontally slidably connected with a telescopic sleeve, and the inner wall of the telescopic sleeve is horizontally slidably connected with a sliding sleeve Sleeve, one end of the sliding sleeve is fixedly connected with the sealing compensation pressure plate, the outer wall of one end of the telescopic sleeve and the sliding sleeve close to the telescopic sleeve is provided with an outer edge, and the telescopic sleeve and the telescopic sleeve are close to the sliding sleeve. One end of the tube is provided with an inner edge for abutting the outer edge.

According to a further arrangement of the present invention, the medium may be an aqueous medium or an oily medium, and the expanded beads may be made of superabsorbent resin or superabsorbent resin.

To sum up, the present invention has the following beneficial effects: after the plug valve is used for a long time, since the sealing surface of the bushing and the plug body will be worn, the probability of leakage is increased. At this time, the operator only needs to rotate the first fastener on the adjusting platen, so that one end of the first fastener is screwed into the valve cover. Then, the adjusting platen is driven to move in the direction of the valve cover. It should be noted that the valve stem in the present application is connected with the driving device by a key, and the valve stem can move in the axial direction and is guaranteed to be driven by the driving device all the time. During the movement of the adjusting platen, the valve stem and the plug body at one end of the valve stem are synchronously driven towards the direction of the bushing, and the plug body has a structure with one end large and one end small, and the cross-sectional area of the end away from the valve stem is smaller than that near the valve. The cross-sectional area of one end of the rod. As a result, when the plug body moves toward the bushing, the contact area with the bushing will gradually increase, so that the plug body and the bushing closely fit to increase the sealing specific pressure.

Description of drawings

Fig. 1 is the structural representation of the plug valve of the first embodiment;

Fig. 2 is the partial enlarged schematic diagram of A area in Fig. 1;

Fig. 3 is the structural representation of the plug valve of the second embodiment;

Fig. 4 is the structural representation of the telescopic tube assembly in Fig. 3;

FIG. 5 is a schematic exploded view of the structure of FIG. 4 .

Reference numerals: 1, valve body; 2, valve cover; 3, valve stem; 4, plug body; 5, driving device; 6, adjusting pressure plate; 7, first fastener; 8, limit groove; 9, Split ring; 10, sealing packing assembly; 11, second gasket; 12, packing pad; 13, first gasket; 14, packing press sleeve; 15, compensation mechanism; 16, packing press plate; 17, second fastener ; 18, bracket; 19, sealing compensation pressure plate; 20, third fastener; 21, clearance; 22, insurance mechanism; 23, telescopic tube assembly; 24, expansion bead; 25, conduit; 26, telescopic sleeve seat; 27 , telescopic sleeve; 28, sliding sleeve; 29, outer edge; 30, inner edge; 31, bushing; 32, butterfly spring.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings.

Example 1:

As shown in Figures 1-2, a compensable sealing plug valve includes a valve body 1, a valve cover 2 and a valve stem 3. The valve body 1 is provided with a valve cavity that communicates with the inlet end and the outlet end. One end of the rod 3 in the valve cavity is provided with a plug body 4, and a bushing 31 is set between the plug body 4 and the valve body. area.

One end of the valve rod 3 away from the plug body 4 is keyed with a driving device 5 that can drive the valve rod 3 to rotate. One end of the valve stem 3 outside the valve body 1 is provided with an adjustment pressure plate 6 , and one side of the adjustment pressure plate 6 is provided with a first fastener 7 , and one end of the first fastener 7 is screwed with the valve cover 2 .

After the plug valve is used for a long time, since the sealing surface of the bushing 31 and the plug body 4 will be worn, the probability of leakage is increased. At this time, the operator only needs to rotate the first fastener 7 on the adjusting platen 6 to screw one end of the first fastener 7 into the valve cover 2 . Further, the adjusting platen 6 is driven to move in the direction of the valve cover 2 . It should be noted that the valve stem 3 in the present application is connected with the driving device 5 by a key, and the valve stem 3 can move axially and is always driven by the driving device 5 . During the movement of the adjusting platen 6, the valve stem 3 and the plug body 4 at one end of the valve stem 3 will be simultaneously driven to move towards the direction of the bushing 31, and the plug body 4 has a structure with one end large and one end small, which is far from the valve stem 3. The cross-sectional area of one end is smaller than the cross-sectional area of one end close to the valve stem 3 . As a result, when the plug body 4 moves toward the bushing 31 , the contact area with the bushing 31 will gradually increase, so that the plug body 4 closely fits the bushing 31 to increase the sealing specific pressure.

Further, the present application can also realize that the adjustment pressure plate 6 and the valve stem 3 are movably matched. One end of the valve rod 3 outside the valve body 1 is provided with a limiting groove 8 , a split ring 9 is arranged in the limiting groove 8 , and one end of the split ring 9 protrudes out of the limiting groove 8 . The adjusting pressure plate 6 is sleeved on the valve stem 3 and the bottom of the adjusting pressure plate 6 is in contact with the split ring 9 exposed outside the limiting groove 8 .

Through the above arrangement, the split ring 9 and the adjusting platen 6 are detachable. When it is necessary to adjust the sealing specific pressure between the plug body 4 and the bushing 31, there is no need to stop work and dismantle the valve, and only need to install the above components to realize the adjustment of the sealing performance of the components inside the valve body 1, which greatly facilitates operation and operation. use.

Further, a sealing packing assembly 10 is provided between the valve stem 3 and the valve cover 2 , and the sealing packing assembly 10 includes a second gasket 11 , a packing gasket 12 , a first gasket 13 and a packing pressure sleeve 14 arranged in sequence from bottom to top , the side of the second gasket 11 away from the packing gasket 12 is in contact with the valve cover 2 . Through the arrangement of the sealing packing assembly 10, the sealing performance between the valve stem 3 and the valve cover 2 can be increased, thereby preventing the medium from overflowing between the valve stem 3 and the valve cover 2, and increasing the medium transmission stability.

Further, the valve cover 2 is provided with a compensation mechanism 15 that can drive the sealing packing assembly 10 to compress to increase the sealing performance between the valve cover 2 and the valve stem 3 .

Further, the compensation mechanism 15 includes a packing pressure plate 16 abutting on the upper end surface of the packing pressure sleeve 14 , a second fastener 17 is passed through one side of the packing pressure plate 16 , and one end of the second fastener 17 is connected to the valve cover. 2 thread fit. By rotating the second fastener 17, one end of the second fastener 17 is screwed into the valve cover 2, thereby driving the packing pressing plate 16 to move towards the direction of the valve cover 2, and then pressing the packing pressing sleeve 14, so that the sealing The packing assembly 10 is compressed to increase the sealing performance between the valve cover 2 and the valve stem 3 . It should be noted that the two ends of the sealing packing assembly 10 are respectively abutted by the packing pressure plate 16 and the valve cover 2 , the valve cover 2 is immobile, and the packing pressure plate 16 is movable. When the distance between the packing pressing plate 16 and the valve cover 2 is reduced, the sealing packing assembly 10 can be squeezed, so as to achieve the effect of compensating the sealing performance between the valve stem 3 and the valve cover 2 .

Further, the plug body 4 is arranged in the shape of a truncated cone or a cone.

Further, the valve cover 2 is provided with a bracket 18 on which the driving device 5 is installed, and one end of the valve stem 3 passes through the bracket 18 and is keyed to the driving device 5 .

Further, a butterfly spring 32 is arranged between the adjustment pressure plate 6 and the first fastener 7 , one end of the butterfly spring 32 is fixedly connected with the adjustment pressure plate 6 , and the other end of the butterfly spring 32 is fixed with the first fastener 7 . connect. The butterfly spring 32 is in a compressed state when the plug valve has no leakage.

When the plug valve leaks, the specific pressure of the seal after wear in the valve is less than the necessary specific pressure. First, the spring pressure is released by the butterfly spring 32, which makes the valve stem move toward the bushing, so as to ensure the sealing performance and prolong the service life of the valve. At the same time, when the sealing pressure released by the butterfly spring is not enough to ensure the sealing performance of the valve, the online leakage of the valve is solved by tightening the first fastener 7 to exert an external force. In the above, the adjusting pressure plate 6 and the butterfly spring 32 form a sealing specific pressure compensation function which is combined with self-force and applied force.

Further, one end of the plug body 4 is in abutment with the valve cover 2 . The application adopts a contact-type valve cover plug body structure. During initial installation, the valve cover 2 directly acts on the large flat end of the plug body 4 to increase the sealing specific pressure of the valve, and also effectively eliminates the pressure difference of the plug body 4 due to the medium pressure difference. The reason is the phenomenon that the sealing specific pressure loss between the plug body 4 and the bushing 31 is caused by the movement of the valve stem 3 in the axial direction.

Embodiment 2:

The difference from the embodiment is that: as shown in FIGS. 3 to 5 , one end of the valve stem 3 outside the valve body 1 is fixedly connected with a sealing compensation pressure plate 19 , and the bottom of the sealing compensation pressure plate 19 is in contact with the upper part of the sealing packing assembly 10 . end face. One side of the sealing compensation pressure plate 19 is provided with a third fastener 20 , and one end of the third fastener 20 is threadedly engaged with the valve cover 2 .

By disposing the sealing compensation pressure plate 19 and the third fastener 20 above, when one end of the third fastener 20 is screwed into the valve cover 2 to reduce the distance between the sealing compensation pressure plate 19 and the valve cover 2 . The valve stem 3 and the plug body 4 at one end of the valve stem 3 can be driven to move toward the bushing 31 synchronously, so as to increase the sealing contact surface between the plug body 4 and the bushing 31 and increase the sealing specific pressure. In addition, the sealing compensation pressing plate 19 can also press the sealing packing assembly 10 to increase the sealing performance between the valve stem 3 and the valve cover 2 . The above-mentioned sealing performance between the valve stem 3 and the valve cover 2 , the plug body 4 and the bushing 31 can be achieved by only one sealing compensation pressure plate 19 .

Further, a gap 21 for the plug body 4 to rotate is formed around the plug body 4 , the valve cover 2 and the valve body 1 together. Due to the sealing effect of the bushing 31 and the sealing packing assembly 10 at both ends of the gap 21 , in the case of no medium leakage, the gap 21 has no medium in the valve cavity to enter. However, when the sealing surface between the bushing 31 and the plug body 4 is worn out after long-term use, which leads to the leakage of the medium, the medium in the valve cavity will enter the gap 21. At this time, if the sealing packing assembly 10 cannot realize the valve When the rod 3 and the valve cover 2 are sealed, the medium will leak to the outside of the plug valve. If the transmitted medium is inflammable, explosive and toxic dangerous goods, there will be potential safety hazards and accidents will occur.

It should be noted that, in the above technical solutions, all the fasteners need to be manually rotated to achieve enhanced sealing in the valve. The medium leakage is sudden, accidental and random. At this time, the operator cannot strengthen the sealing in the valve or even close the valve when the leakage occurs. Therefore, a safety mechanism 22 is needed to solve this problem.

Further, a safety mechanism 22 is also included. The safety mechanism 22 includes a telescopic tube assembly 23 . One end of the telescopic tube assembly 23 is fixedly connected to the valve stem 3 , and the other end of the telescopic tube assembly 23 is fixedly connected to the sealing compensation pressure plate 19 . The telescopic tube assembly 23 has a cavity inside, and the cavity contains a number of expansion beads 24 that will expand when the volume of the medium is encountered.

One side of the sealing compensation pressure plate 19 is provided with a conduit 25 .

When there is a risk of sudden leakage in the valve, so that the operator has no time to close the valve. Then the medium in the valve will enter the gap 21 and push into the conduit 25 under the pressure of the medium in the valve, so that the medium will be pushed into the cavity of the telescopic tube assembly 23 and contact with the expansion beads 24 in the cavity. The expansion bead 24 will expand when it encounters the medium, and the top valve stem 3 and the telescopic tube assemblies 23 on both sides in contact with the expansion bead 24 are fixed in position, and the telescopic tube assembly 23 can only move along its circumferential direction, and is in contact with the expansion bead 24. The sealing compensation platen 19 in contact with the expansion bead 24 is relatively movable.

It should also be noted that the two ends of the telescopic tube assembly 23 are fixedly connected to the valve stem 3 and the sealing compensation pressure plate 19 respectively, and the telescopic tube assembly 23 will extend axially. In the process of expanding the expansion beads 24, a force towards the valve cover 2 will be exerted on the sealing compensation pressure plate 19, so as to shorten the distance between the sealing compensation pressure plate 19 and the valve cover 2, so as to realize the valve stem 3 and the valve cover 2 and the plug body. 4 and the sealing performance between the bushing 31.

In the above process, since the valve stem 3 drives the plug body 4 to move toward the bushing 31, the size of the gap 21 formed around the plug body 4, the valve cover 2 and the valve body 1 will be enlarged. Once the gap 21 is enlarged, Part of the residual medium in the conduit 25 will flow back into the gap 21 . Through this process, the expanded beads 24 are gradually separated from the contact with the medium, and after the expanded beads 24 are gradually dried naturally, their volume will be reduced. In addition, the residual medium located in the gap 21 is naturally dried.

Further, the telescopic tube assembly 23 includes a telescopic sleeve seat 26 fixedly connected with the valve rod 3, the inner wall of the telescopic sleeve seat 26 is horizontally slidably connected with a telescopic sleeve 27, and the inner wall of the telescopic sleeve 27 is horizontally slidably connected with a sliding sleeve 28, One end of the sliding sleeve 28 is fixedly connected with the sealing compensation pressure plate 19 .

The outer wall of one end of the telescopic sleeve 27 and the sliding sleeve 28 close to the telescopic sleeve base 26 is provided with an outer edge 29 , and one end of the telescopic sleeve 26 and the telescopic sleeve 27 close to the sliding sleeve 28 is provided with an inner edge 30 for contacting the outer edge 29 .

Further, one end of the expansion bead 24 is in contact with the sealing compensation pressing plate 19 .

Further, the medium may be an aqueous medium or an oily medium, and the corresponding expansion beads 24 may be made of superabsorbent resin or superabsorbent resin.

The specific embodiment is only an explanation of the present invention, and it is not a limitation of the present invention. Those skilled in the art can make modifications to the present embodiment without creative contribution as needed after reading this specification, but only in the claims of the present invention are protected by patent law.

Claims (10)

1. A compensable sealing plug valve, comprising a valve body (1), a valve cover (2) and a valve stem (3), the valve body (1) being internally provided with a valve communicating with an inlet end and a discharge end One end of the valve stem (3) in the valve cavity is provided with a plug body (4), a bushing (31) is arranged between the plug body (4) and the valve body (1), the valve stem (3) A drive device (5) that can drive the valve stem (3) to rotate is keyed to one end away from the plug body (4), characterized in that the end of the plug body (4) away from the valve stem (3) is transverse The cross-sectional area is smaller than the cross-sectional area of one end close to the valve stem (3), the end of the valve stem (3) outside the valve body (1) is provided with an adjustment pressure plate (6), and one side of the adjustment pressure plate (6) passes through A first fastener (7) is provided, and one end of the first fastener (7) is screwed with the valve cover (2). 2. A compensable sealing plug valve according to claim 1, characterized in that: a limit groove (8) is provided at one end of the valve stem (3) outside the valve body (1), and the limit A split ring (9) is arranged in the groove (8), one end of the split ring (9) protrudes out of the limiting groove (8), and the regulating pressure plate (6) is sleeved on the valve stem (3). And the bottom of the adjusting pressing plate (6) abuts against the split ring (9) exposed outside the limiting groove (8). 3. A compensable sealing plug valve according to claim 2, characterized in that: a sealing packing assembly (10) is arranged between the valve stem (3) and the valve cover (2), and the sealing packing The assembly (10) includes a second washer (11), a packing pad (12), a first washer (13) and a packing press sleeve (14) arranged in sequence from bottom to top, the second washer (11) being away from the packing pad One side of (12) is in contact with the valve cover (2). 4. A compensable sealing plug valve according to claim 3, characterized in that: the valve cover (2) is provided with a drivable sealing packing assembly (10) for compression to increase the valve cover (2) Compensation mechanism (15) for sealing performance with the valve stem (3), the compensation mechanism (15) includes a packing pressure plate (16) abutting on the upper end face of the packing pressure sleeve (14), the packing pressure plate (16) ) is provided with a second fastener (17), and one end of the second fastener (17) is threadedly matched with the valve cover (2). 5 . The compensable sealing plug valve according to claim 1 , wherein the plug body ( 4 ) is arranged in the shape of a truncated cone or a cone. 6 . 6. A compensable sealing plug valve according to claim 3, characterized in that: one end of the valve stem (3) outside the valve body (1) is fixedly connected with a sealing compensation pressure plate (19), and the The bottom of the sealing compensation pressure plate (19) is in contact with the upper end surface of the sealing packing assembly (10), and a third fastener (20) is passed through one side of the sealing compensation pressure plate (19). The third fastener One end of (20) is threaded with the valve cover (2). 7 . The compensable sealing plug valve according to claim 6 , wherein the plug body ( 4 ), the valve cover ( 2 ) and the valve body ( 1 ) are surrounded together to form an available plug body. 8 . (4) Rotational clearance (21). 8. A compensable sealing plug valve according to claim 7, characterized in that: further comprising a safety mechanism (22), the safety mechanism (22) comprising a telescopic tube assembly (23), the telescopic One end of the tube assembly (23) is fixedly connected to the valve stem (3), the other end of the telescopic tube assembly (23) is fixedly connected to the sealing compensation pressure plate (19), and the telescopic tube assembly (23) has a cavity inside, A plurality of expansion beads (24) that will expand when meeting the volume of the medium are built in the cavity; a conduit (25) is passed through one side of the sealing compensation pressure plate (19), and one end of the conduit (25) is connected to the telescopic tube. The inner cavity of the component (23) is communicated with, and the other end of the conduit (25) is communicated with the gap (21) through the valve cover (2). 9 . The compensable sealing plug valve according to claim 8 , wherein the telescopic tube assembly ( 23 ) comprises a telescopic sleeve seat ( 26 ) fixedly connected to the valve stem ( 3 ), and the A telescopic sleeve (27) is horizontally slidably connected to the inner wall of the telescopic sleeve seat (26), and a sliding sleeve (28) is horizontally slidably connected to the inner wall of the telescopic sleeve (27). The sealing compensation pressure plate (19) is fixedly connected, and the outer wall of one end of the telescopic sleeve (27) and the sliding sleeve (28) close to the telescopic sleeve seat (26) is provided with an outer edge (29), and the telescopic sleeve seat (26) One end of the telescopic sleeve (27) close to the sliding sleeve (28) is provided with an inner edge (30) for abutting against the outer edge (29). 10. A compensable sealing plug valve according to claim 9, characterized in that: the medium can be an aqueous medium or an oily medium, and the expansion bead (24) can be a super absorbent resin or a super oil absorbent Made of resin.

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