CN116906599A - Floating hard seal butterfly valve and working principle thereof - Google Patents

Abstract

The invention discloses a floating hard sealing butterfly valve, which comprises a bottom cover, wherein a valve body is arranged on the bottom cover, a support is arranged at the top of the valve body, a lower bearing is embedded at the bottom of the valve body, an upper bearing is embedded at the top of the valve body, a short valve shaft is arranged in the lower bearing, a long valve shaft is arranged in the upper bearing, the short valve shaft and the long valve shaft are both fixed through a pin shaft, a valve clack is arranged between the short valve shaft and the long valve shaft, an elastic metal sealing ring is sleeved outside the valve clack, a hard sealing contact surface of the elastic metal sealing ring is not fixed on the valve clack, but floats on the valve clack and is independent of the valve clack, a 0-shaped sealing ring is also arranged between the elastic metal sealing ring and the valve clack, a gland is arranged outside the elastic metal sealing ring, and a micro gap exists between the gland and the elastic metal sealing ring; the invention has compact structure, can automatically compensate the clearance between the valve clack and the valve seat, obtains better sealing performance, can not scratch the surface of the sealing pair to cause leakage, and greatly prolongs the service life of the hard seal.

Description

Floating hard seal butterfly valve and working principle thereof

Technical Field

The invention relates to the technical field of butterfly valves, in particular to a floating hard sealing butterfly valve and a working principle thereof.

Background

Currently, the hard seal butterfly valve adopts a bidirectional hard contact seal, as shown in figure 8,

this solution suffers from the following drawbacks:

1. when the butterfly valve is closed, the valve clack 9 is stressed and deformed due to the action of machining errors and assembly errors, so that gaps exist on the sealing surface, and leakage is caused;

2. in the opening and closing process of the butterfly valve, the closing and pressing part of the valve clack 9 and the valve seat 13 exceeds the maximum allowable contact stress, so that the sealing surface can be scratched, and leakage is caused;

3. excessive driving force applied by the driving mechanism can cause over travel of the sealing surface, negative angle contact and leakage.

In summary, the current hard sealing technology cannot achieve zero leakage.

Disclosure of Invention

The invention aims to overcome the defects and shortcomings of the prior art and provides a floating hard seal butterfly valve.

In order to achieve the above purpose, the invention adopts the following technical scheme: the utility model provides a floating hard seal butterfly valve, includes the bottom, set up the valve body on the bottom, the top of valve body sets up the support, the bottom of valve body is inlayed and is set up the lower bearing, and its top is inlayed and is set up the upper bearing, set up the spool in the lower bearing, set up the spool in the upper bearing, and spool are all fixed through the round pin axle, set up the valve clack between spool and the spool, its innovation point lies in: the outside of valve clack cup joints elastic metal seal circle, still set up O type sealing washer between elastic metal seal circle and the valve clack, elastic metal seal circle's hard seal contact surface is not fixed in on the valve clack, but floats on the valve clack, and is independent of the valve clack, elastic metal seal circle's outside sets up the gland, there is the trace clearance between gland and the elastic metal seal circle, the valve body inner wall sets up the disk seat of metal material, the disk seat is spacing to elastic metal seal circle, the outside of disk seat sets up the retaining ring, the retaining ring is fixed through spacing step, and spacing to the disk seat.

Further, a valve seat sealing ring is arranged between the valve seat and the valve body.

Furthermore, the short valve shaft and the long valve shaft are also sleeved with V-shaped sealing rings.

The working principle of the floating hard seal butterfly valve is characterized in that the seal meets the following conditions:

(1) Maximum contact stress sigma _max Greater than the specific sealing pressure sigma _f Taking 2-3 safety factors to ensure the sealing performance of zero leakage;

(2) Maximum contact stress sigma _max Should be less than the allowable contact stress of the sealing material;

(3) After the elastic metal sealing ring meets the two conditions, the pressure F born by the elastic metal sealing ring can be evenly distributed along the circumferential direction of the sealing ring, and the sealing force is evenly distributed, so that the occurrence of over-cutting is avoided, and zero leakage is achieved.

After the structure is adopted, the invention has the beneficial effects that:

1. the invention has compact structure, can automatically compensate the clearance between the valve clack and the valve seat, obtains better sealing performance, can not scratch the surface of the sealing pair to cause leakage, and greatly prolongs the service life of the hard seal.

2. The invention can realize modularized installation, is convenient to maintain, reduces the use cost, reduces the hard seal production cost, provides a high-performance and high-cost-performance hard seal butterfly valve for customers, greatly promotes the use and popularization of the hard seal butterfly valve, and has great market value.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is an enlarged schematic view of FIG. 1 at A;

FIG. 3 is an enlarged schematic view at B in FIG. 2;

FIG. 4 is a schematic diagram of the present invention

FIG. 5 is a schematic diagram of a second embodiment of the present invention;

FIG. 6 is a schematic diagram of the present invention when the back surface is pressed;

FIG. 7 is a schematic diagram of the front side of the present invention when pressed;

fig. 8 is a schematic diagram of a prior art structure.

Reference numerals illustrate:

1 bottom cover, 2 valve body, 3 support, 4 lower bearing, 5 upper bearing, 6 short valve shaft, 7 long valve shaft, 8 round pin axle, 9 valve clack, 10 elastic metal seal circle, 11O formula seal circle, 12 gland, 13 disk seat, 14 retaining ring, 15 disk seat seal circle, 16V formula seal circle, 17 disk seat adjusting bolt, 18 disk seat supporting ring.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings and detailed description. It should be understood that the detailed description is presented by way of example only and is not intended to limit the invention.

Example 1

Referring to fig. 1-3, a floating hard seal butterfly valve comprises a bottom cover 1, a valve body 2 is arranged on the bottom cover 1, a support 3 is arranged at the top of the valve body 2, a lower bearing 4 is inlaid at the bottom of the valve body 1, an upper bearing 5 is inlaid at the top of the valve body, a short valve shaft 6 is arranged in the lower bearing 4, a long valve shaft 7 is arranged in the upper bearing 5, the short valve shaft 6 and the long valve shaft 7 are both fixed through a pin shaft 8, a valve clack 9 is arranged between the short valve shaft 6 and the long valve shaft 7, an elastic metal sealing ring 10 is sleeved outside the valve clack 9, a hard seal contact surface of the elastic metal sealing ring 10 is not fixed on the valve clack 9, but floats on the valve clack, an O-shaped sealing ring 11 is also arranged between the elastic metal sealing ring 10 and the valve clack 9, a gland 12 is arranged outside the elastic metal sealing ring 10, a micro gap exists between the gland 12 and the elastic metal sealing ring 10, a valve seat 13 made of metal is arranged on the inner wall of the valve body 2, the valve seat 13 is limited by the elastic metal sealing ring 10, a retainer ring 14 is arranged outside the valve seat 13, and a retainer ring 14 is fixed through a limiting step, and the valve seat 13 is limited by the retainer ring. Specifically, the core of the invention is a floating hard sealing technology, namely, a hard sealing contact surface of an elastic metal sealing ring 10 on a valve clack is not fixed on the valve clack, but a floating technology is adopted, and the elastic metal sealing ring 10 is independent of the valve clack and has a certain amount of serial movement in the radial direction; the elastic metal sealing ring 10 is a sealing pair of the valve clack; a micro gap exists between the gland 12 and the elastic metal sealing ring 10 to prevent the axial movement of the metal hard sealing ring; the O-shaped sealing ring 11 is used for blocking leakage of a pipeline medium from the back of the gland 12 and the elastic metal sealing ring 10; the valve seat 13 is limited by a retainer ring 14 and a self-provided step, so that the valve seat 13 is prevented from axially moving in a stringing way.

In this embodiment, a valve seat seal 15 is provided between the valve seat 13 and the valve body 2. The valve seat seal 15 serves to block leakage of pipe medium from the bottom of the valve seat 13.

In this embodiment, the short valve shaft 6 and the long valve shaft 7 are also sleeved with V-shaped sealing rings 16. The V-shaped sealing ring 16 is used to improve the tightness between the short valve shaft 6 and the long valve shaft 7 and the valve body 2.

Example 2

Referring to fig. 4, in which: the valve clack closing pretightening force F is the integral of the contact stress sigma of the sealing surface in the contact width b; maximum contact stress sigma _max The contact width b is related to the magnitude of the interference C, the valve seat sealing radius R and the valve clack sealing surface radius R, and generally, the larger the comprehensive radius of the contact surface is, the larger the contact surface width b is and the sealing specific pressure sigma is _f The smaller; the seal therefore has to meet the following conditions:

(1) The maximum contact stress sigma max is larger than the sealing specific pressure sigma f, and the safety coefficient is 2-3, so that the sealing performance of zero leakage is ensured;

(2) The maximum contact stress sigma max should be smaller than the allowable contact stress of the sealing material;

(3) After the elastic metal sealing ring meets the two conditions, the pressure F born by the elastic metal sealing ring can be evenly distributed along the circumferential direction of the sealing ring, and the sealing force is evenly distributed, so that the occurrence of over-cutting damage is avoided, and zero leakage is achieved.

Referring to fig. 4, when the butterfly valve is closed, the resilient metal seal 10 at the flap 9 comes into contact with the valve seat 13; because the elastic metal sealing ring 10 at the valve clack 9 has a serial quantity in the radial direction, the valve seat 13 also has a serial quantity in the radial direction, and the two parts are sealed between the sealing contact force sigma max and the maximum allowable contact stress, namely, the sealing contact force requirement can be met, and the sealing contact force is lower than the maximum stress of the scratch surface; therefore, due to the bidirectional floating, the sealing pair (the elastic metal sealing ring 10) can effectively compensate the sealing problem caused by the shape error within a certain limit, namely, the shape can be automatically adjusted to adapt to the sealing tightness requirement, the self-adaptive sealing requirement is achieved, and zero leakage is achieved

Referring to fig. 5, f is the pressure applied to the elastic metal seal ring, R is the valve seat sealing radius, Δr is the difference between the valve seat sealing radius R and the valve flap sealing surface radius R;

referring to fig. 6, the back pressure P-off condition of the butterfly valve is: the delta R1 is more than or equal to delta R2, and F2=F1, namely the pressure F born by the elastic metal sealing ring is evenly distributed along the circumferential direction of the sealing ring, and the sealing force is evenly distributed, so that the occurrence of over-cutting damage is avoided, and zero leakage is achieved;

referring to fig. 7, the back pressure P-off condition of the butterfly valve is: the Δr1 is less than or equal to Δr2, f2=f1, the pressure F born by the elastic metal sealing ring can be evenly distributed along the circumferential direction of the sealing ring, and the sealing force is evenly distributed, so that the occurrence of over-cutting damage is avoided, and zero leakage is achieved.

The foregoing is merely illustrative of the present invention and not restrictive, and other modifications and equivalents thereof may occur to those skilled in the art without departing from the spirit and scope of the present invention.

Claims (4)

1. The utility model provides a floating hard seal butterfly valve, includes the bottom, set up the valve body on the bottom, the top of valve body sets up the support, the bottom of valve body is inlayed and is set up the lower bearing, and its top is inlayed and is set up the upper bearing, set up the spool in the lower bearing, set up the spool in the upper bearing, and spool are all fixed through the round pin axle, set up the valve clack between spool and the spool, its characterized in that: the outside of valve clack cup joints elastic metal seal circle, elastic metal seal circle's hard seal contact surface is not fixed in on the valve clack, but floats on the valve clack, and is independent of the valve clack, still set up 0 type sealing washer between elastic metal seal circle and the valve clack, elastic metal seal circle's outside sets up the gland, there is the trace clearance between gland and the elastic metal seal circle, the valve body inner wall sets up the disk seat of metal material, the disk seat is spacing to elastic metal seal circle, the outside of disk seat sets up the retaining ring, the retaining ring is fixed through spacing step, and spacing to the disk seat.

2. A floating hard seal butterfly valve according to claim 1, wherein: and a valve seat sealing ring is arranged between the valve seat and the valve body.

3. A floating hard seal butterfly valve according to claim 1, wherein: and the short valve shaft and the long valve shaft are also sleeved with V-shaped sealing rings.

4. The working principle of the floating hard seal butterfly valve is characterized in that the seal meets the following conditions:

(1) Maximum contact stress sigma _max Greater than the specific sealing pressure sigma _f Taking 2-3 safety factors to ensure the sealing performance of zero leakage;

(2) Maximum contact stress sigma _max Should be less than the allowable contact stress of the sealing material;

(3) After the elastic metal sealing ring meets the two conditions, the pressure F born by the elastic metal sealing ring can be evenly distributed along the circumferential direction of the sealing ring, and the sealing force is evenly distributed, so that the occurrence of over-cutting is avoided, and zero leakage is achieved.