CN205350424U - High pressure ultra -low temperature upper assembling type ball valve composite seal disk seat - Google Patents

Abstract

The utility model discloses a combined sealing valve seat of a high-pressure ultra-low temperature top-mounted ball valve. The combined sealing valve seat of the ball valve includes a combined sealing valve seat at the upstream end of the valve and a combined sealing valve seat at the downstream end of the valve. The combined sealing valve seat at the upstream end of the valve and the downstream end of the valve The seal between the combined seal valve seat and the top entry valve body adopts a lip seal ring. The utility model has the advantage of long-term stable work in the ultra-low temperature medium, ensuring no internal leakage in the ultra-low temperature medium.

Description

High pressure and ultra low temperature top entry ball valve combined sealing seat

technical field

The utility model relates to a combined sealing valve seat, in particular to a combined sealing valve seat of a high-pressure and ultra-low temperature top-mounted ball valve.

Background technique

The combined sealing seat of the normal temperature ball valve can realize two functions, and the applicable temperature is -29℃～+150℃. One is double block and bleed (Double block and bleed) function, as shown in Figure 1, including ball 1, opening fixed ring 2, normal temperature valve seat seal ring 3, valve seat ring 4, spring 5, fire ring 6, "O" Type ring retaining ring 7, "O" type ring I8, "O" type ring II9 and valve body 10. This function can seal the upstream and downstream ends of the valve at the same time, and discharge to the lower pressure upstream or downstream end when the cavity is overpressured. The other is the double isolation and discharge (Double isolation and bleed) function, as shown in Figure 2. Including ball 1, opening fixed ring 2, normal temperature valve seat seal ring 3, valve seat ring 4, spring 5, fire protection ring 6, "O" ring retaining ring 7, "O" ring I8, "O" ring II9 , Valve body 10. The biggest difference from the normal temperature ball valve combined sealing seat with double cut-off and relief functions is that the two ends of the "O" ring I8 are respectively equipped with "O" ring retaining rings 7 to realize the "O" ring I8 under the action of high-pressure medium. Both sealing directions will not squeeze into the matching gap between the outer circle of the valve seat ring 4 and the valve body 10 . This function can seal the upstream and downstream ends of the valve at the same time, but the cavity must be equipped with a pressure relief device to ensure that the pressure in the cavity exceeds 1.33 times the design pressure and is released from the pressure relief device.

LNG is condensed into a liquid by cooling gaseous natural gas at normal pressure to -162°C. In the natural gas liquefaction process, a large number of high-pressure and ultra-low temperature top entry ball valves are used. The combined sealing valve seat of the normal temperature ball valve with the above two functions cannot meet the requirements of the working conditions. The existing problems are as follows:

There are three problems in the normal temperature ball valve combined sealing valve with double cut-off and relief functions: First, when the cavity is overpressured, it discharges to the upstream or downstream end with lower pressure. This relief method is dangerous, especially at the downstream end of the valve. During maintenance, it is easy to cause damage to maintenance personnel and equipment. The second is that the normal temperature valve seat sealing ring is not suitable for ultra-low temperature conditions, and the valve leaks a lot. The third is that at normal temperature, the seal of the valve seat ring and the valve body adopts a rubber "O" ring, and the rubber is easily brittle and cannot be sealed in an ultra-low temperature medium.

There are also three problems in the room temperature ball valve combined sealing valve with double isolation and relief functions: one is that the cavity must be provided with a pressure relief device, which increases the leakage point of the valve body. The second is that the normal temperature valve seat sealing ring is not suitable for ultra-low temperature conditions, and the valve leaks a lot. The third is that at normal temperature, the seal of the valve seat ring and the valve body adopts a rubber "O" ring, and the rubber is easily brittle and cannot be sealed in an ultra-low temperature medium.

Utility model content

The technical problem to be solved by the utility model is to provide a combined sealing valve seat of a high-pressure and ultra-low temperature top entry ball valve suitable for ultra-low temperature working conditions and good sealing performance.

In order to solve the above technical problems, the utility model provides a high-pressure ultra-low temperature top entry ball valve combined sealing seat, the combined sealing valve seat of the ball valve includes a combined sealing valve seat at the upstream end of the valve and a combined sealing valve seat at the downstream end of the valve, and a combined sealing valve seat at the upstream end of the valve Combined sealing valve seat and the downstream end of the valve The sealing between the combined sealing valve seat and the top entry valve body adopts a lip seal ring.

The combined sealing valve seat at the upstream end of the valve includes an anti-rotation ring, an anti-rotation pin, a single C-shaped lip seal ring, a lip seal retainer ring, an ultra-low temperature valve seat ring, an ultra-low temperature valve seat seal ring, a valve seat snap ring, Anti-rotation baffle, butterfly spring, pressure ring and ultra-low temperature fireproof ring; the single C-shaped lip seal ring is installed on the inner hole of the top entry valve and the outer circle of the ultra-low temperature valve seat ring, and the single C-shaped lip faces the upstream of the valve At the end, a lip seal ring is set behind the single C-shaped lip seal ring. The ultra-low temperature valve seat seal ring is pressed into the annular seal groove of the ultra-low temperature valve seat ring by external force. There are threads on the outer circle of the ultra-low temperature valve seat ring. The clasp ring makes the ultra-low temperature valve seat ring and the ultra-low temperature valve seat sealing ring close to or withdraw from the ultra-low temperature sphere.

The single C-shaped lip seal ring is composed of a polymer material jacket embedded with a metal energy storage spring.

The single C-shaped lip seal ring is installed on the inner hole of the top entry valve and the outer circle of the ultra-low temperature valve seat ring. The embedded metal energy storage spring is in a compressed state, which will force the sealing lip of the jacket to be close to the surface to be sealed. Provides the cut-off load required for sealing when there is no medium pressure. When there is medium pressure, the medium pressure is applied to the sealing lip of the jacket to achieve sealing. The higher the pressure, the better the sealing performance. Any deformation or wear of the jacket is compensated by the embedded metal energy storage spring. In high-pressure working conditions, the lip seal retaining ring is set behind the single C-shaped lip seal ring to prevent damage to the single C-shaped lip seal ring under high pressure.

The combined sealing valve seat at the downstream end of the valve includes an anti-rotation ring, an anti-rotation pin, an ultra-low temperature valve seat ring, an ultra-low temperature valve seat sealing ring, a valve seat snap ring, an anti-rotation baffle, a butterfly spring, a pressure ring, and an ultra-low temperature fireproof ring and double C-shaped lip seal ring; the double C-shaped lip seal ring is installed on the inner hole of the top entry valve and the outer circle of the ultra-low temperature valve seat ring, the double C-shaped lip faces the downstream end of the valve, and the ultra-low temperature valve seat seal ring It is pressed into the annular sealing groove of the ultra-low temperature valve seat ring by external force. There are threads on the outer circle of the ultra-low temperature valve seat ring. The double C-shaped lip seal ring of the combined sealing valve seat at the downstream end can achieve good sealing in both directions and realize the isolation function.

The anti-rotation ring is welded on the top-entry valve body, and several pin holes are processed on the axial circumference. Rotational movement.

An anti-rotation baffle is arranged in the tightening groove of the outer circle of the valve seat snap ring, and is fixed on the top entry valve body.

The ultra-low temperature valve seat sealing ring is pressed into the annular sealing groove of the ultra-low temperature valve seat ring by external force. Threads are processed on the outer circle of the ultra-low temperature valve seat ring, and the ultra-low temperature valve seat ring and the ultra-low temperature valve seat sealing ring are pressed against or withdrawn from the ultra-low temperature sphere by rotating the seat snap ring. When the ultra-low temperature valve seat ring and the ultra-low temperature valve seat sealing ring retreat from the ultra-low temperature ball, the ultra-low temperature ball can be taken out from the top entry valve body to realize online inspection and maintenance. When the ultra-low temperature valve seat ring and the ultra-low temperature valve seat sealing ring are close to the ultra-low temperature sphere to achieve sealing, in order to avoid the thread of the ultra-low temperature valve seat ring and the seat snap ring from loosening under the pressure of the medium, resulting in sealing failure, the valve seat snap ring An anti-rotation baffle is arranged in the tightening groove of the outer circle, and is fixed on the top entry valve body with set screws.

The butterfly spring is installed between the anti-rotation baffle and the pressure ring to continuously provide pre-tightening force for the sealing ring of the ultra-low temperature valve seat to cling to the ultra-low temperature sphere.

The ultra-low temperature fire protection ring is installed on the inner hole of the top-entry valve and the outer circle of the ultra-low temperature valve seat ring, and is compressed with a pressure ring to realize the fire prevention function.

The ultra-low temperature valve seat sealing ring is made of polychlorotrifluoroethylene material or tetrafluoroethylene material, which works stably for a long time in the ultra-low temperature medium and ensures no internal leakage in the ultra-low temperature medium.

The principle of overpressure relief of the cavity of the utility model: when the medium remaining in the cavity is abnormally boosted, the force generated by the pressure of the cavity on the back of the valve seat at the upstream end is less than that of the cavity pressure acting on the sealing surface of the valve seat at the upstream end Due to the force generated by the area, the combined sealing valve seat at the upstream end is separated from the ultra-low temperature sphere, and the cavity pressure is released to the upstream end. At this time, the force generated by the cavity pressure on the back acting area of the valve seat at the downstream end is greater than the force generated by the cavity pressure on the sealing surface of the valve seat at the downstream end, and the cavity pressure will not be released to the downstream end. When the downstream end is overhauled, it will not cause damage to the maintenance personnel and equipment.

The superior effect of the present utility model is:

1) The ultra-low temperature valve seat sealing ring of the utility model is made of polytrifluoroethylene or tetrafluoroethylene material, which can work stably for a long time in the ultra-low temperature medium, and ensures that there is no internal leakage in the ultra-low temperature medium;

2) The valve seat and the upstream end of the valve body of the utility model are sealed with a single C-shaped lip seal ring, and the embedded metal energy storage spring provides the cut-off load required for sealing when there is no medium pressure. When there is medium pressure, the medium Pressure is applied to the sealing lip of the jacket to achieve sealing. The higher the pressure, the better the sealing performance; under high pressure conditions, a lip sealing ring retainer is installed behind the lip sealing ring to prevent damage to the lip sealing ring under high pressure;

3) The valve seat and the downstream end of the valve body of the utility model are sealed with double C-shaped lip seals, which can achieve good sealing in both directions and realize the isolation function;

4) The utility model realizes that after the medium remaining in the cavity is abnormally boosted, the pressure of the cavity is released to the upstream end, and will not be released to the downstream end; when the downstream end is overhauled, it will not cause damage to maintenance personnel and equipment.

4) The utility model makes the ultra-low temperature valve seat ring and the ultra-low temperature valve seat sealing ring close to or retreat from the ultra-low temperature sphere by rotating the valve seat snap ring, which is convenient for maintenance.

Description of drawings

The accompanying drawings constituting a part of this application are used to provide a further understanding of the utility model, and the schematic embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute improper limitations to the utility model. In the attached picture:

Fig. 1 is the schematic diagram of the combined sealing valve seat of the normal temperature ball valve with double cut-off and discharge functions;

Figure 2 is a schematic diagram of the combined sealing seat of the normal temperature ball valve with double isolation and relief functions;

Fig. 3 is a schematic diagram of the combined sealing valve seat of the high-pressure ultra-low temperature top entry ball valve of the present invention;

Explanation of symbols in the figure

1—sphere; 2—opening fixed ring;

3—seat ring at room temperature; 4—seat ring;

5—spring; 6—fire ring;

7—"O" ring retaining ring; 8—"O" ring I;

9—"O" ring II; 10—valve body;

11—Top entry valve body; 12—Anti-rotation ring;

13—anti-rotation pin; 14—single C-shaped lip seal;

15—lip seal retaining ring; 16—cryogenic valve seat ring;

17—Cryogenic valve seat sealing ring; 18—Cryogenic sphere;

19—seat snap ring; 20—anti-rotation baffle;

21—Butterfly spring; 22—Set screw;

23—pressure ring; 24—ultra-low temperature fire ring;

25—double C-shaped lip seal ring; A—acting area on the back of the upstream valve seat;

B—acting area of the sealing surface of the valve seat at the upstream end; C—acting area of the back of the valve seat at the downstream end;

D—the effective area of the sealing surface of the valve seat at the downstream end.

detailed description

The embodiments of the utility model will be described in detail below in conjunction with the accompanying drawings, but the utility model can be implemented in various ways defined and covered by the claims.

The embodiment of the utility model will be described in detail below in conjunction with FIG. 3 .

The figure shows a schematic structural view of an embodiment of the utility model. As shown in Fig. 3, the utility model provides a high-pressure and ultra-low temperature top entry ball valve combination sealing valve seat suitable for ultra-low temperature working conditions and good sealing performance. The left side of Figure 3 is the combined sealing valve seat at the upstream end of the valve, including top entry valve body 11, anti-rotation ring 12, anti-rotation pin 13, single C-shaped lip seal ring 14, lip seal ring retaining ring 15, ultra-low temperature valve Seat ring 16, ultra-low temperature valve seat sealing ring 17, ultra-low temperature sphere 18, valve seat snap ring 19, anti-rotation baffle 20, butterfly spring 21, set screw 22, pressure ring 23 and ultra-low temperature fireproof ring 24. The right side of Fig. 3 is the combined sealing valve seat at the downstream end of the valve, including top entry valve body 11, anti-rotation ring 12, anti-rotation pin 13, ultra-low temperature valve seat ring 16, ultra-low temperature valve seat sealing ring 17, ultra-low temperature ball 18, valve seat Snap ring 19, anti-rotation baffle 20, butterfly spring 21, set screw 22, pressure ring 23, ultra-low temperature fireproof ring 24 and double C-shaped lip seal ring 25.

The top-entry valve body 11 can be inspected and repaired online after the pipeline is depressurized, which simplifies maintenance.

The anti-rotation ring 12 is welded on the top entry valve body 11, and several pin holes are processed on the axial circumference. After the anti-rotation pin 13 is assembled with the anti-rotation ring 12 and the ultra-low temperature valve seat ring 16, the axial movement of the ultra-low temperature valve seat ring 16 is restricted, and no rotational motion is allowed.

The single C-shaped lip seal ring 14 is composed of a polychlorotrifluoroethylene or tetrafluoroethylene jacket embedded with a metal energy storage spring. The jacket acts as a seal under the action of medium pressure and belongs to the self-tightening seal. Because polytrifluorochloroethylene or tetrafluoroethylene has extremely high chemical stability, good low temperature resistance, and good swelling resistance to the medium, it can replace rubber "O" rings for ultra-low temperature conditions. The single C-shaped lip seal ring 14 is installed on the inner hole of the top entry valve body 1 and the outer circle of the ultra-low temperature valve seat ring 16, and the C-shaped lip faces the upstream end of the valve. After the single C-shaped lip seal ring 14 is installed, the embedded metal energy storage spring is in a compressed state, which will force the sealing lip of the jacket to be close to the surface to be sealed, and provide the cut-off load required for sealing when there is no medium pressure. When there is medium pressure, the medium pressure is applied to the sealing lip of the jacket to achieve sealing. The higher the pressure, the better the sealing performance. Any deformation or wear of the jacket is compensated by the embedded metal energy storage spring.

During high-pressure working conditions, the lip-type sealing ring retaining ring 15 arranged behind the single C-shaped lip-type sealing ring 14 prevents the single-C-type lip-type sealing ring 14 from being damaged under high pressure.

The ultra-low temperature valve seat sealing ring 17 is pressed into the annular sealing groove of the ultra-low temperature valve seat ring 16 by external force. Threads are processed on the outer circle of the ultra-low temperature valve seat ring 16 , and the ultra-low temperature valve seat ring 16 and the ultra-low temperature valve seat sealing ring 17 are tightly attached to or withdrawn from the ultra-low temperature sphere 18 by rotating the valve seat snap ring 19 . After the ultra-low temperature seat ring 16 and the ultra-low temperature valve seat sealing ring 17 retreat from the ultra-low temperature ball 18, the ultra-low temperature ball 18 can be taken out from the top entry valve body 11 to realize online inspection and maintenance. When the ultra-low temperature valve seat ring 16 and the ultra-low temperature valve seat sealing ring 17 are close to the ultra-low temperature ball 18 to achieve sealing, in order to avoid the loosening of the threads of the ultra-low temperature valve seat ring 16 and the valve seat snap ring 19 under the pressure of the medium, resulting in sealing failure, An anti-rotation baffle 20 is arranged in the tightening groove of the outer circle of the valve seat snap ring 19 , and is fixed on the top entry valve body 11 with set screws 22 .

The ultra-low temperature valve seat sealing ring 17 is made of polychlorotrifluoroethylene or tetrafluoroethylene material, which can work stably for a long time in the ultra-low temperature medium, and ensures that there is no internal leakage in the ultra-low temperature medium.

The butterfly spring 21 is installed between the anti-rotation baffle plate 20 and the pressure ring 23 to continuously provide pre-tightening force for the ultra-low temperature valve seat sealing ring 17 to cling to the ultra-low temperature ball 18 .

The ultra-low temperature fire protection ring 24 is installed on the inner hole of the top entry valve body 1 and the outer circle of the ultra-low temperature valve seat ring 16 and is compressed with a pressure ring 23 to realize the fire prevention function.

The biggest difference between the combined sealing valve seat at the downstream end and the combined sealing valve seat at the upstream end is that the double C-shaped lip sealing ring 25 is used instead of the single C-shaped lip sealing ring 14 and the lip sealing ring back-up ring 15 . The double C-shaped lip seal ring 25 can achieve good sealing in both directions and realize the isolation function.

Cavity overpressure relief principle: When the medium remaining in the cavity is abnormally boosted, the force generated by the cavity pressure on the back of the valve seat at the upstream end is less than the force generated by the cavity pressure on the sealing surface of the upstream valve seat B Due to the generated force, the combined sealing valve seat at the upstream end breaks away from the ultra-low temperature spheroid 18, and the cavity pressure is released to the upstream end. At this time, the force generated by the cavity pressure on the acting area C of the valve seat back at the downstream end is greater than the force generated by the cavity pressure on the acting area D of the valve seat sealing surface at the downstream end, and the cavity pressure will not be released to the downstream end. When the downstream end is overhauled, it will not cause damage to the maintenance personnel and equipment.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. For those skilled in the art, the present utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims (9)

1. A combination sealing valve seat of a high-pressure ultra-low temperature top-entry ball valve, characterized in that: the combined sealing valve seat of the ball valve includes a combined sealing valve seat at the upstream end of the valve and a combined sealing valve seat at the downstream end of the valve, and the combined sealing valve seat at the upstream end of the valve and the valve The seal between the combined sealing valve seat at the downstream end and the top entry valve body adopts a lip seal ring. 2. The combined sealing valve seat of the high-pressure and ultra-low temperature top entry ball valve according to claim 1, wherein the combined sealing valve seat at the upstream end of the valve includes an anti-rotation ring, an anti-rotation pin, a single C-shaped lip seal ring, lip seal retaining ring, ultra-low temperature valve seat ring, ultra-low temperature valve seat seal ring, valve seat snap ring, anti-rotation baffle, butterfly spring, pressure ring and ultra-low temperature fire ring; the single C-shaped lip seal ring is installed on On the inner hole of the top entry valve and the outer circle of the ultra-low temperature valve seat ring, the single C-shaped lip faces the upstream end of the valve, and a lip-type sealing ring back-up ring is arranged behind the single C-shaped lip sealing ring, and the ultra-low temperature valve seat sealing ring is pressed in by external force In the annular sealing groove of the ultra-low temperature valve seat ring, threads are provided on the outer circle of the ultra-low temperature valve seat ring, and the rotating valve seat snap ring makes the ultra-low temperature valve seat ring and the ultra-low temperature valve seat sealing ring close to or retreat from the ultra-low temperature sphere. 3. The high-pressure and ultra-low temperature top-entry top-entry ball valve combined sealing valve seat according to claim 2, characterized in that: the single C-shaped lip seal ring is made of a polymer material jacket embedded with a metal energy storage spring. 4. The combined sealing valve seat of the high-pressure and ultra-low temperature top entry ball valve according to claim 1, wherein the combined sealing valve seat at the downstream end of the valve includes an anti-rotation ring, an anti-rotation pin, an ultra-low temperature valve seat ring, and an ultra-low temperature valve seat sealing ring, valve seat snap ring, anti-rotation baffle, butterfly spring, pressure ring, ultra-low temperature fireproof ring and double C-shaped lip sealing ring; On the outer circle of the seat ring, the double C-shaped lip faces the downstream end of the valve. The ultra-low temperature valve seat seal ring is pressed into the annular sealing groove of the ultra-low temperature valve seat ring by external force. There are threads on the outer circle of the ultra-low temperature valve seat ring. The clasp ring makes the ultra-low temperature valve seat ring and the ultra-low temperature valve seat sealing ring close to or withdraw from the ultra-low temperature sphere. 5. The high-pressure and ultra-low temperature top-entry top-entry ball valve combined sealing valve seat according to claim 2 or 4, characterized in that: the anti-rotation ring is welded on the top-entry valve body, and several pin holes are processed on the axial circumference to prevent rotation. The pin is assembled with the anti-rotation ring and the ultra-low temperature valve seat ring to limit the axial movement of the ultra-low temperature valve seat ring. 6. The high-pressure and ultra-low temperature top-entry top-entry ball valve combined sealing valve seat according to claim 4, characterized in that: an anti-rotation baffle is set in the tightening groove of the outer circle of the valve seat snap ring, and is fixed on the top-entry valve body . 7. The combined sealing seat of the high-pressure and ultra-low temperature top entry ball valve according to claim 4, characterized in that: the butterfly spring is installed between the anti-rotation baffle and the pressure ring, so that the sealing ring of the ultra-low temperature valve seat is close to the ultra-low temperature ball and lasts Provides preload. 8. The combined sealing seat of high-pressure and ultra-low temperature top-entry ball valve according to claim 4, characterized in that: the ultra-low temperature fireproof ring is installed on the inner hole of the top-entry valve and the outer circle of the ultra-low temperature valve seat ring and is compressed with a pressure ring. 9. The high-pressure and ultra-low temperature top entry ball valve combined sealing valve seat according to claim 2 or 4, characterized in that: the sealing ring of the ultra-low temperature valve seat is made of polychlorotrifluoroethylene or tetrafluoroethylene.