CN112112982A - A kind of two-way pure metal sealing triple eccentric butterfly valve and manufacturing method thereof - Google Patents

Abstract

The invention provides a bidirectional pure metal sealing triple eccentric butterfly valve and a manufacturing method thereof, which relate to the field of valve processing and manufacturing equipment, and the butterfly valve comprises a valve body, a butterfly plate, a valve rod and a valve seat, wherein a flow channel is arranged in the valve body, the valve rod is vertically arranged and penetrates through the flow channel, the butterfly plate is arranged in the flow channel and is fixedly installed on the valve rod, an annular valve body boss is arranged on the valve body along the inner wall of the flow channel, the valve seat is arranged on one side of the valve body boss, and a fastening screw used for connecting the valve seat is arranged on the valve body boss; the cross section of the valve seat is S-shaped, the edge of the butterfly plate is provided with an annular step surface, and a sealing ring and a pressing ring are mounted on the step surface. The invention has the advantages that: 1. the bidirectional sealing is reliable; 2. the driving torque is small; 3. the pure metal is hard sealed, and has high temperature resistance, corrosion resistance and wear resistance.

Description

A kind of two-way pure metal sealing triple eccentric butterfly valve and manufacturing method thereof

technical field

The invention relates to the field of valve processing and manufacturing equipment, in particular to a two-way pure metal sealing triple eccentric butterfly valve and a manufacturing method thereof.

Background technique

At present, most of the two-way sealed triple-eccentric butterfly valves on the market have three disadvantages: 1) Most of them can only be used in pipelines with medium temperature ≤ 200 °C. The main reason is that the seal between the valve seat and the valve body is inseparable from the rubber ring, and the long-term heat-resistant working temperature of the best heat-resistant rubber (fluorine rubber) is ≤ 200 °C; 2) The sealing ring has a short life: use for a period of time Leakage occurs after time (even switching a dozen times), and the amount of leakage increases with time and switching times. The main reason is the material and processing of the sealing pair. The sealing ring of most triple eccentric butterfly valves adopts the multi-layer structure of 304+ flexible graphite. During the extrusion process of the switch and the flow erosion of the pipeline medium, the graphite particles are easily precipitated and washed away by the medium. As a result, the travel cavity on the sealing surface, with the expansion of the cavity, the leakage of the sealing surface is also increasing; while the pure metal hard-sealed triple eccentric butterfly valve, due to the limited processing technology, the sealing surface processing accuracy, sealing surface The surface roughness, surface hardness of the sealing surface and insufficient wear resistance cause the sealing ring to be scratched during the switching process, causing leakage; 3) Poor corrosion resistance: due to cost pressure, most triple eccentric butterfly valves have The sealing auxiliary materials are all common and inexpensive materials. These materials are not only poor in wear resistance, but also have poor mechanical properties and corrosion resistance. After a long time of use, the sealing surface is often corroded, which will also cause leakage.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a two-way pure metal sealing triple eccentric butterfly valve and a manufacturing method thereof, so as to solve the problem of poor sealing performance of the existing butterfly valve.

The present invention is realized as follows: a two-way pure metal sealing triple eccentric butterfly valve includes a valve body, a butterfly plate, a valve stem and a valve seat, a flow channel is arranged in the valve body, and the valve stem is vertically arranged and penetrates through the valve body. the flow channel, the butterfly plate is arranged in the flow channel and fixedly installed on the valve stem, wherein,

An annular valve body boss is arranged on the valve body along the inner wall of the flow channel, the valve seat is arranged on one side of the valve body boss, and a valve body boss is provided on the valve body boss for a fastening screw connecting the valve seat;

The cross section of the valve seat is S-shaped, and the valve seat includes a pressure bearing plate, a swing link and a base from top to bottom, and a first compression chamber is arranged between the pressure plate and the swing link, A second compression cavity is arranged between the swing link and the base, and the base is fixedly connected to the valve body boss through the tightening screw; the rear end surface of the base is connected to the valve body boss abutting, a swing gap is set between the pressure-bearing plate and the rear end surface of the swing link and the valve body boss;

The edge of the butterfly plate is provided with an annular stepped surface, a sealing ring and a pressure ring are installed on the stepped surface, the pressure ring is connected with the butterfly plate by screws, and the sealing ring is clamped on the between the pressure ring and the butterfly plate; the sealing ring has a conical outer conical surface, and the top surface of the pressure bearing plate is in the shape of an inner conical surface that is internally matched with the outer conical surface of the sealing ring.

Preferably, a translation gap is set between the inner circular surface of the sealing ring and the stepped surface of the butterfly plate.

Preferably, a sealing gasket is provided between the sealing ring and the butterfly plate.

Preferably, a corrosion-resistant material layer is processed on the inner conical surface of the pressure-bearing plate.

Preferably, the cross section of the sealing ring is in the shape of large inside and small outside.

Preferably, a chamfer is provided at the front end of the bottom surface of the base, a groove is provided at the transition position between the valve body boss and the valve body, the groove is filled with filler, and the upper surface of the filler is provided is a slope slope matched with the chamfered slope.

Preferably, the stainless steel sealing surface is surfacing on the slope inclined surface.

Preferably, the upper end of the valve rod is connected to the turbine device through the upper sleeve, and between the valve rod and the upper sleeve, from bottom to top, a packing, a packing gland, and a transmission bracket are arranged in sequence; the valve The lower end of the rod is rotatably arranged in the lower bushing, and an end cover is arranged at the bottom of the lower bushing.

The manufacturing method of a two-way pure metal sealing triple eccentric butterfly valve according to any one of claims 1-9, wherein the manufacturing method of the valve seat comprises the following steps:

a. cutting;

b. Flat front and rear surfaces, processing positioning circle and base circle of inner conical surface;

c. Surfacing inner conical surface;

d. Rough turning, fine turning, and fine grinding of the inner conical surface;

e. The first and second compression chambers of the valve seat, and the front and rear surfaces of the vehicle are smoothed;

f. Corrosion-resistant material layer on the outer conical surface of the valve seat;

g. Grind the burrs to make the edges smooth.

The manufacturing method of a two-way pure metal sealing triple eccentric butterfly valve according to any one of claims 1-9, wherein the manufacturing method of the sealing ring comprises the following steps:

a. cutting;

b. Flat front and rear surfaces, processing positioning circle and base circle of outer conical surface;

c. Surfacing outer conical surface;

d. Rough turning, fine turning, and fine grinding of the inner conical surface;

e. Grind the burrs to make the edges smooth.

By adopting the above technical scheme, the advantages of the present invention are: 1. Reliable bidirectional sealing; 2. Small driving torque; 3. Pure metal hard sealing, high temperature resistance, corrosion resistance and wear resistance.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

Fig. 1 is the structural representation of the present invention;

Fig. 2 is the sectional structure schematic diagram of the present invention;

3 is a structural schematic diagram of the natural extension of the valve seat in the open state of the present invention;

Fig. 4 is the structural representation of the sealing ring of the present invention;

Figure 5 is a schematic structural diagram of the open state of the butterfly valve when the medium is flowing forward;

Figure 6 is a schematic diagram of the structure of the sealing part in the closed state of the butterfly valve when the medium is flowing forward;

Figure 7 is a schematic structural diagram of the open state of the butterfly valve when the medium flows in reverse;

Figure 8 is a schematic diagram of the structure of the sealing part in the closed state of the butterfly valve when the medium flows in reverse;

Fig. 9 is the structural representation of the sealing ring of the present invention;

Fig. 10 is a schematic view of the structure of the gradient slope of the present invention.

In the figure: 1—valve body, 2—disc, 3—valve stem, 4—flow channel, 5—fastening pin, 6—valve body boss, 7—valve seat, 71—bearing plate, 72—swing Connecting rod, 73—base, 74—first compression chamber, 75—second compression chamber, 8—fastening screw, 9—swing clearance, 10—sealing ring, 11—pressing ring, 12—screw, 13—external cone Face, 14—translational clearance, 15—sealing gasket, 16—corrosion resistant material layer, 17—chamfer, 18—groove, 19—slope slope, 20—upper bushing, 21—turbine device, 22—packing, 23 - packing gland, 24 - transmission bracket, 25 - lower bushing, 26 - end cover.

Detailed ways

The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are intended to illustrate the present invention, but not to limit the scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation or a specific orientation. construction and operation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first", "second", and "third" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

As shown in Figures 1 and 2, the present invention provides a two-way pure metal sealing triple eccentric butterfly valve and a manufacturing method thereof, comprising a valve body 1, a butterfly plate 2, a valve stem 3 and a valve seat, and a valve body 1 is provided with a The flow channel 4, the valve stem 3 is vertically arranged and penetrates the flow channel 4, the butterfly plate 2 is arranged in the flow channel 4 and is fixedly installed on the valve stem 3, and the butterfly plate 2 and the valve stem 3 are connected by a fastening pin 5, The synchronous rotation of the butterfly plate 2 and the valve stem 3 is realized. The present invention is also provided with a valve seat 7 and a sealing ring 10 . The upper end of the valve stem 3 is connected to the turbine device 21 through the upper bushing 20 , and between the valve stem 3 and the upper bushing 20 , a packing 22 , a packing gland 23 , and a transmission bracket 24 are sequentially arranged from bottom to top. The lower end of the valve rod 3 is rotatably arranged in the lower bushing 25 , and an end cover 26 is arranged at the bottom of the lower bushing 25 . Preferably, the filler 22 is made of high temperature resistant flexible graphite material, and the upper and lower shaft sleeves are made of high temperature resistant chrome-molybdenum steel material and are subjected to nitriding treatment.

The working principle of the present invention is as follows: the valve stem is driven by the worm gear device, and the butterfly plate assembly (the butterfly plate, the sealing ring and the butterfly plate pressing ring) is driven by the fastening pin to perform a rotating action within the range of 0-90°. When the butterfly plate rotates to be perpendicular to the axis of the flow channel, the conical surface of the outer edge of the sealing ring just matches the inner conical surface of the valve seat in the valve body to achieve the effect of cutting off the flow of the medium, that is, the valve is closed. When the butterfly plate rotates in the reverse direction, the sealing ring is driven away from the sealing surface of the valve seat, so that the medium flows through the valve and flows downstream. When the butterfly plate rotates to the point where the front plane is parallel to the axis of the flow channel, the opening stroke is exactly 90° and reaches the fully open position.

Further, as shown in FIG. 3 , in the present invention, an annular valve body boss 6 is provided on the valve body 1 along the inner wall of the flow channel 4 , and the valve seat 7 is arranged on one side of the valve body boss 6 . The boss 6 is provided with a tightening screw 8 for connecting the valve seat 7. The function of the tightening screw 8 is to connect the valve body boss 6 and the valve seat 7, so that the valve body boss 6 and the valve seat 7 are tightly fitted. , the seat position is fixed under load.

Further, the cross section of the valve seat 7 of the present invention is S-shaped, the valve seat 7 includes a pressure bearing plate 71 , a swing link 72 and a base 73 from top to bottom, and a pressure bearing plate 71 and the swing link 72 are provided with a A second compression chamber 75 is provided between the first compression chamber 74 , the swing link 72 and the base 73 , and the base 73 is fixedly connected to the valve body boss 6 through the tightening screw 8 . The rear end surface of the base 73 is in contact with the valve body boss 6 , and a swing gap 9 is provided between the pressure receiving plate 71 and the rear end surface of the swing link 72 and the valve body boss 6 . Since the cross section of the valve seat 7 is S-shaped, within the force range of the pressure bearing plate 71, the valve seat 7 as a whole can be compressed or elongated in the radial direction. It can produce a morphological change that swings back and forth.

Further, as shown in FIG. 4 , the edge of the butterfly plate 2 of the present invention is provided with an annular stepped surface, and a sealing ring 10 and a pressure ring 11 are installed at the stepped surface, and the pressure ring 11 is connected with the butterfly plate 2 through screws 12, The sealing ring 10 is clamped in the space between the pressure ring 11 and the butterfly plate 2 . Preferably, a sealing washer 15 is provided between the sealing ring 10 and the butterfly plate 2, and the sealing ring 10 and the sealing washer 15 are made of metal or graphite.

The sealing ring 10 of the present invention has a tapered outer conical surface 13 , and the top surface of the pressure-receiving plate 71 is an inner conical surface that fits with the outer edge surface 13 of the sealing ring 10 . Further, a corrosion-resistant material layer 16 is surfacing on the outer conical surface 13 and the inner conical surface, and the roughness of the contact surface is controlled by grinding to improve the sealing accuracy and corrosion resistance of the friction pair.

As shown in Figure 5 and Figure 6, the forward sealing principle of the present invention: when the medium flows forward, the butterfly plate is in an open state, and the valve seat is in a natural stretched state. There is a swinging gap between the rear end face of the valve seat and the valve body boss. This clearance provides elastic space for the valve seat. When the butterfly plate is closed, after the sealing ring is in contact with the conical surface of the valve seat, due to the preset interference between the sealing surfaces and the elasticity of the valve seat, the valve seat is deformed backward while ensuring the sealing, which effectively reduces the sealing effect. The friction torque of the surface reduces wear. When the sealing ring reaches the fully closed position, the medium pressure on the upstream side of the disc rises to the highest pressure, and the disc assembly (disc, sealing ring, pressure ring and valve stem) is pushed toward the valve seat, and all manufacturing errors, clearances and elasticity The total displacement value formed by the deformation is exactly equal to the designed clearance value between the back of the valve seat and the valve body boss. Therefore, the elastic deformation of the valve seat ensures the sealing pressure ratio between the sealing surfaces to ensure the sealing, and the force of the medium acting on the disc is shared by the valve stem and the valve body boss. Avoid overpressure damage to the sealing surface caused by excessive medium force.

As shown in Figures 7 and 8, the reverse sealing principle of the present invention: when the medium flows in the reverse direction, the butterfly plate is in an open state, and the valve seat is in a natural stretched state. When the butterfly plate is closed to the initial contact between the sealing ring and the sealing surface of the valve seat, the valve seat and the sealing ring are elastically deformed due to the pre-designed interference, and they match each other and there is a sufficient sealing specific pressure between the sealing surfaces. The butterfly valve begins to seal, and the pressure difference begins to appear before and after the butterfly plate. As the pressure on the upstream side increases, the butterfly plate assembly (disc, sealing ring, pressure ring, valve stem, etc.) moves to the downstream side under the action of pressure, and the total moving distance is the sum of the assembly clearance and elastic deformation of each part. At this time, the S-ring of the valve seat is also deflected to the downstream side due to its own elastic force and medium pressure, and the conical sealing surfaces are still tightly attached together to ensure the reverse sealing state all the time. After ensuring that sufficient sealing specific pressure is generated between the sealing surfaces, the excess medium pressure is borne by the valve stem to avoid the wear of the sealing surface.

As shown in Figure 9, due to the influence of manufacturing and assembly errors, the outer conical surface of the sealing ring cannot be completely matched with the inner conical surface of the valve seat during assembly, which results in that the sealing ratio of one side of the sealing ring is too large and the side sealing Insufficient specific pressure produces leakage, which also increases the wear of one-side sealing surface and increases the switching torque. Therefore, in the present invention, a translation gap 14 is provided between the inner circular surface of the sealing ring 10 and the stepped surface of the butterfly plate 2, the cross section of the sealing ring 10 is in the shape of large inside and small outside, and the width of the cross section of the sealing ring 10 is h , the h value is small, and it is easy to deform to adapt to the inner conical surface of the valve seat. The sealing ring 10 and the butterfly plate 2 can not only ensure the sealing, but also allow the sealing ring 10 to automatically translate according to the position of the valve seat 7 during the closing process, so that the two conical surfaces are automatically aligned. The structure of large inside and small outside not only ensures that the sealing ring has sufficient strength, but also can produce reasonable elastic deformation under the action of closing force and medium force to make up for the size difference between the two conical surfaces caused by manufacturing errors.

The sealing ring of the present invention can be automatically aligned, so that the sealing ring and the valve seat can be uniformly fitted, thereby ensuring the stability of sealing performance, minimum wear, minimum friction force, and low driving force.

Further, as shown in FIG. 10, the present invention is provided with a chamfer 17 at the front end of the bottom surface of the base 73, a groove 18 is provided at the transition position between the valve body boss 6 and the valve body 1, and the groove is filled with filler, The upper surface of the filler is provided as a sloping slope 19 that matches the slope of the chamfer 17 . The stainless steel sealing surface is surfacing on the slope 19.

The valve seat boosting sealing principle of the present invention: between the valve seat 7 and the valve body 1, through the sloping slope 19 under the tightening action of the tightening screw 8, a sufficient sealing specific pressure is generated to realize the sealing. In order to ensure the sealing performance and prevent leakage caused by corrosion, the stainless steel sealing surface is surfacing on the slope 19. The valve seat and the valve body have both hardness difference and elasticity to ensure reliable sealing.

The manufacturing process flow of the valve seat of the present invention is as follows:

a. cutting;

b. Flat front and rear surfaces, processing positioning circle and base circle of inner conical surface;

c. Surfacing inner conical surface;

d. Rough turning, fine turning, and fine grinding of the inner conical surface;

e. Install the tooling separately, the first and second compression chambers of the valve seat, and the front and rear surfaces of the trimming;

f. The outer conical surface of the valve seat;

g. Grind the burrs to make the edges smooth.

The manufacturing process of the sealing ring is as follows:

a. cutting;

b. Flat front and rear surfaces, processing positioning circle and sealing surface base circle;

c. Surfacing sealing surface;

d. Rough turning, fine turning and fine grinding of sealing surfaces;

e. Put on the tooling, the front and rear faces of the car sealing ring respectively;

f. Grind the burrs to make the edges smooth.

Further, in the two steps d, after the rough turning, the fine turning is repeated to the size before grinding, to ensure that the stainless steel ring does not generate internal stress due to processing and clamping, and does not generate dimensional fluctuations due to the fast advancing speed;

The advantages of the present invention are:

1. Two-way sealing is reliable; the key to sealing the butterfly valve is the machining accuracy, surface finish, surface hardness and mutual agreement between the sealing pairs. When other conditions are determined, it is particularly important to ensure that the sealing pair can still be highly matched when the components on one side of the sealing pair are elastically deformed under the action of the medium pressure. The S-shaped valve seat of the present invention solves the above problems well: the sealing compensation is higher, the heat resistance temperature is higher, the corrosion resistance and wear resistance are better, and the service life is longer. No matter which side bears the medium pressure, the sealing pair (the outer conical sealing surface of the disc sealing ring and the inner conical sealing surface of the valve seat) can be deformed or moved in the same direction of the favorable sealing under the action of the medium force, thereby establishing a stable sealing ratio. pressure to achieve good sealing performance.

2. The driving torque is small; the setting of the S-shaped structure increases the elastic deformation range of the valve seat 7, so that the valve seat has a swingable space along the axis of the flow channel. Therefore, when the butterfly plate is closed, after the circumferential contact is completed, its elasticity can not only enable the sealing pair to obtain a good sealing specific pressure under low pressure difference, and realize the sealing function, but also enable the butterfly plate to continue to close. Backward under the thrust, the friction torque of the sealing surface is reduced, which is beneficial to the switch operation.

3. Pure metal hard seal, high temperature resistance, corrosion resistance and wear resistance; the valve body and butterfly plate of the present invention are made of WCB material that can withstand high temperature of 425 °C, and other parts and materials can be configured in different configurations according to different medium temperatures.

4. The structure is simple, and the size and precision of the valve seat and sealing ring are guaranteed by special tooling;

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be The technical solutions described in the foregoing embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions in the embodiments of the present invention.

Claims (10)

1. A bidirectional pure metal sealed triple offset butterfly valve comprises a valve body, a butterfly plate, a valve rod and a valve seat, wherein a flow passage is arranged in the valve body, the valve rod is vertically arranged and penetrates through the flow passage, the butterfly plate is arranged in the flow passage and is fixedly arranged on the valve rod,

an annular valve body boss is arranged on the valve body along the inner wall of the flow passage, and the valve seat body is annular and arranged on one side of the valve body boss;

the cross section of the valve seat is S-shaped, the valve seat comprises a bearing plate, a swinging connecting rod and a base from top to bottom, a first compression cavity is arranged between the bearing plate and the swinging connecting rod, a second compression cavity is arranged between the swinging connecting rod and the base, and the base is fixedly connected with the valve body boss through a fastening screw; the rear end face of the base is abutted against the front side face of the valve body boss, and a swinging gap is formed between the rear end faces of the pressure bearing plate and the swinging connecting rod and the front side face of the valve body boss;

the edge of the butterfly plate is provided with an annular step surface, a sealing ring and a pressing ring are arranged on the step surface, the pressing ring is connected with the butterfly plate through a screw, and the sealing ring is clamped between the pressing ring and the butterfly plate; the sealing ring is provided with a conical outer conical surface, and the top surface of the bearing plate is in the shape of an inner conical surface matched with the outer conical surface of the sealing ring.

2. The bi-directional pure metal sealed triple offset butterfly valve of claim 1, wherein a translational gap is provided between the inner circular surface of the seal ring and the step surface of the butterfly plate.

3. A bi-directional pure metal sealed tri-eccentric butterfly valve according to claim 1, wherein a sealing gasket is provided between the sealing ring and the butterfly plate.

4. The bi-directional pure metal sealed triple offset butterfly valve according to claim 1, wherein a corrosion resistant material layer is formed on the inner conical surface of the pressure plate.

5. The bi-directional pure metal sealed triple offset butterfly valve of claim 1, wherein the cross-section of the seal ring is large inside and small outside.

6. The bidirectional pure metal sealed triple offset butterfly valve according to claim 1, wherein a chamfer is provided at a front end of a bottom surface of the base, a groove is provided at a transition position of the valve body boss and the valve body, the groove is filled with a filler, and an upper surface of the filler is provided with a slope surface matching with an inclined surface of the chamfer.

7. A bi-directional pure metal sealed triple offset butterfly valve according to claim 6, wherein a stainless steel sealing surface is deposited on said sloped surface.

8. The bidirectional pure metal sealed triple eccentric butterfly valve according to claim 1, wherein the upper end of the valve rod passes through an upper shaft sleeve to be connected with a turbine device, and a packing, a packing gland and a transmission bracket are sequentially arranged between the valve rod and the upper shaft sleeve from bottom to top; the lower end of the valve rod is rotatably arranged in the lower shaft sleeve, and an end cover is arranged at the bottom of the lower shaft sleeve.

9. The method of any one of claims 1 to 8, wherein the method of manufacturing the valve seat comprises the steps of:

a. blanking;

b. flattening the front end surface and the rear end surface, and processing a positioning circle and an inner conical surface base circle;

c. surfacing an inner conical surface;

d. roughly turning, finely turning and finely grinding the inner conical surface;

e. turning a first compression cavity and a second compression cavity of the valve seat, and flattening the front end surface and the rear end surface;

f. turning a corrosion resistant material layer on the outer conical surface of the valve seat;

g. and (5) polishing burrs to make each edge smooth.

10. The method of claim 9, wherein the method of manufacturing the seal ring comprises the steps of:

a. blanking;

b. flattening the front end surface and the rear end surface, and processing a positioning circle and a base circle of an external conical surface;

c. surfacing an outer conical surface;

d. roughly turning, finely turning and finely grinding the inner conical surface;

e. and (5) polishing burrs to make each edge smooth.

Images