FI79602C - KULVENTIL. - Google Patents

Description

79602

This invention relates to a ball valve for pipelines, etc., and more particularly to a double shut-off type ball valve in which a sealing ring 5 supporting a valve seat acts by means of pressure inside the housing cavity to prevent abnormal increase in pressure in the housing cavity.

In those types of ball valves in which the stem has to rotate the ball in the housing and the fluid passage is opened and closed by rotating the ball, the single-seal type and the double-seal type are known as typical sealing methods, as described in Piping Technique, March 1979, pages 78-79.

Figure 1 shows a section of the main part of a conventional single-closing type ball valve, in which the ball 2 as a valve member 15 is located in the housing 1 so as to rotate around a stem (not shown) to open and close the fluid passage 3. An annular seat holder 4 is fitted in the housing to surround the fluid passage and an annular valve seat 6 is mounted between the seat holder 4 and the outer ring 5 attached to the seat holder 20, the valve seat 6 being opposite the ball. The outer ring is forced towards the ball from its rear by means of compression springs 7 located at predetermined intervals in the circumferential direction so that the annular valve seat 25 is brought into contact with the surface of the ball to provide a seal between the seat stop and the ball.

In addition, an O-ring 8 is located on the outer circumferential surface of the seat retainer where the seat retainer is in sliding contact with the inner wall surface of the housing at a point 30 having an outer diameter larger than the valve seat sealing point diameter to provide a seal between the housing and the seat retainer. The ball valve shown further has a sealant channel 9 for temporarily replacing the sealing action in the event of damage to the valve seat to inject sealant to the sealing point 5 by means of an injector (not shown) which opens in the vicinity of the inner surface of the seal.

When the fluid channel is subjected to fluid pressure, and the primary side fluid pressure is higher than the secondary-side hydraulic pressure P, one such type of closure valve 10 of a so-called. Itsepuristava force, i.

(022 to D12> 'P1 to P3>' proportional to the area of the annular part, the width of which corresponds to the difference between the sealing point diameter of the valve seat 6 and the outer diameter Dj of the seat stop at the point where the O-ring 8 is located, 15 and fluid pressure P ^ receptacle cavity and the internal pressure P L input of the differential pressure, therefore, a force istukanpidäkkeen rear surface, so that the valve seat comes into close contact with the ball and thus on the primary fluid is sealed.

20 On the other hand when the fluid leaks on the primary receptacle cavity, thereby increasing the pressure inside the receptacle cavity P ^ higher than the secondary side fluid pressure P, the power of π 2 2 - (D - D1) to (P3 - Pi) acts on the pressure-reducing force to urge the istukanpidäkkeen back to the rear surface of the feet 25. When this pressure-reducing force becomes greater than the compressive force of the compression spring 7, the valve seat is therefore withdrawn from the ball, whereby the pressure in the housing cavity can be released to the secondary side to prevent an abnormal increase in the pressure inside the housing cavity.

3 79602

an abnormal increase in the internal pressure receptacle cavity may thus be one shut-off valve according to the block type of reacting a receptacle cavity in communication with the secondary side but the liquid compression occurs only in the primary side.

In view of this, a known double-shut-off type valve is proposed, which, as shown in Fig. 2, is further provided with a diverter valve 21 and can seal the liquid on both the primary and secondary sides. In this double-closing type valve, the first 10 0 rings 8 and 11 are placed on the outer circumferential surface of the seat stop 4 in sliding contact with the inner wall surface of the housing 1 at a point whose outer diameter D 1 is larger than the sealing point diameter D 1 of the valve seat 6 and the second O-ring 12 is located at a point whose outer diameter 15 is less than, and a closed chamber 13 sealed by O-rings 11 and 12 is formed between the inner wall surface of the housing and the rear surface of the seat stop.

The diverter valve 21, on the other hand, has a piston 23 which is axially movable in the cylinder 22. This piston divides the interior of the cylinder into a primary chamber 24 which communicates with the fluid passage via line 26 and a secondary chamber 25 which communicates with the housing cavity 10 via line 27. And it works by bringing the closed chamber 13 into contact with the fluid passage through line 28 when the fluid pressure is greater than the pressure inside the nest cavity, and contacting the nest cavity with the closed chamber through the same line 28 when the pressure inside the nest cavity is greater than the fluid pressure. disclosed, for example, in U.S. Patent Nos. 3,776,506 and 3,856,261.

30 Under normal conditions, is on the primary fluid pressure P ^ therefore larger than the receptacle cavity 10 of the internal pressure P L to the primary side fluid pressure P? 4 is brought into contact with concentrated 79602 colony through the shuttle valve 21. π 2 2 and thus self-compressing force - (D, - D1) (P1 - P.,)

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istukanpidäkkeen affect the back surface of the valve seat 6 on the primary fluid seals.

5 However, when the primary side fluid leak receptacle cavity or internal pressure of the receptacle cavity is increased due to increase in temperature and receptacle cavity internal pressure P L becomes larger when the secondary side fluid pressure P £ within the allowed limits, and the piston 23 moves to the right in Fig receptacle cavity placing 10 into communication with the compressed colony itsepuristava V February 2 force - (D - D) (P - P) of the istukanpidäkkeen 4 Ί jjz the back surface of the valve seat 6 summarizes the secondary side fluid. In other words, the leakage of liquid from the primary side to the secondary side is prevented.

15 receptacle cavity is of such a double closing type valve, the thus closed regard to pressure, so that, in particular, the incompressible fluid in the case of, for example, in the case that the primary side fluid leak receptacle cavity for more than a predetermined allowable amount, increases the internal pressure at 20 receptacle cavity abnormally, resulting in failure damage to the valve and shuttle valve. Such an abnormal increase in pressure inside the nest cavity can be avoided by attaching a relief valve to the nest cavity. However, this is not possible 25 in the case where the liquid is flammable. Even if the capacity of the relief valve is insufficient, regardless of the type of fluid, damage to the valve cannot be avoided.

It is therefore a technical problem of the present invention to provide a double shut-off type ball valve in which, as the pressure inside the nest cavity increases above a predetermined level 5 79602, the seat retainer operates by using this pressure to contact the nest cavity with the fluid passage to prevent abnormal pressure inside the cavity.

To solve the above technical problem, the present invention provides a ball valve having a housing; a movable spherical closure member for opening and closing the fluid passage in the housing; an annular seat retainer disposed in the housing opposite the spherical closure member to surround the fluid passage; an annular valve seat attached to the seat stop opposite the spherical closure member; a first 0-ring positioned at a point having an outer diameter greater than the sealing point diameter of the valve seat on the outer circumferential surface of the seat stop, the seat stop being in sliding contact with the inner wall surface of the housing; a second O-ring located at a point having a sealing diameter smaller than the sealing point diameter; a closed chamber formed between the inner wall surface of the housing and the rear surface of the seat stop between the first and second O-rings; and a reversing valve having an access cylinder divided by an axially movable main piston into a primary chamber communicating with the fluid passage and a secondary chamber communicating with the housing cavity, the main piston being arranged to communicate the fluid passage and the closed chamber with each other through the primary chamber when the fluid pressure in the fluid passage is higher than the pressure inside the nest cavity and to bring the housing cavity and the closed chamber into contact with each other when the pressure inside the nest cavity is higher than the fluid pressure in the fluid passage.

The ball valve is characterized in that the diverter valve further has a lower cylinder which is divided by an axially movable lower piston into a control chamber communicating with the housing cavity as well as a secondary chamber and a conduit chamber communicating with the outside air or the primary chamber, forcing the control chamber downstream. is transferred against the action of the compression spring when the pressure inside the housing cavity reaches a predetermined level to contact the closed chamber with the fluid passage through the primary chamber, the pressure reducing force acting on the seat stop through the farm.

In the case that the primary side fluid pressure is greater than the internal pressure of the receptacle cavity, the primary side fluid pressure in accordance with the present invention the ball valve is led in a sealed outbreaks, while in the event that the receptacle cavity internal pressure is greater than the secondary fluid pressure, the receptacle cavity is connected to the closed chamber so that in either case itsepuristava force acts istukanpidäkkeeseen and for this reason the liquid is condensed on both the primary and secondary sides. On the other hand, when the pressure inside the nest cavity abnormally exceeds the predetermined allowable limits and reaches a predetermined level, the main piston moves to the left under this control colony pressure so that the closed chamber communicates with the main duct fluid As a result, the nest cavity communicates with the fluid passage and the pressure inside the nest cavity is discharged into the fluid passage to prevent an abnormal increase in pressure.

A ball valve according to an embodiment of the present invention will now be described with reference to Figs. 3-5, in which components common to Figs. 1 and 2 have the same reference numerals.

Fig. 1 shows a section of the main part of a conventional single-shut-off type ball valve; 7 79602

Fig. 2 shows a section of the main part of a conventional double-shut-off type ball valve;

Figures 3-5 show sections of a main part of a ball valve according to an embodiment of the present invention; and Fig. 6 shows a section of the main part of a ball valve according to another embodiment of the invention.

Fig. 3 shows a section of the main part of a ball valve according to an embodiment of the present invention, in which an annular seat holder 4 is arranged in the housing 1 around the fluid passage 3 10 and an annular valve seat 6 opposite the ball 2 is mounted between the seat holder 4 and the outer ring 5 attached thereto. The outer ring is forced towards the ball by compression springs 7 fixed to the inner wall surface of the housing at predetermined intervals in the circumferential direction 15 so that the annular valve seat contacts the ball surface to provide a seal between the seat stop and the ball. In addition, the first O-ring 8 and 11 and the second O-ring 12 are disposed on the outer circumferential surface of the seat retainer where the seat retainer 20 is in sliding contact with the inner wall surface of the housing. The outer diameter of the seat stop at the point where the first 0-rings are located is larger than the sealing point diameter of the valve seat, while the outer diameter of the seat stop from the point where the second O-ring is located is smaller than the sealing point diameter of the valve seat.

The ball valve of the present invention is further provided with a diverter valve 31. This diverter valve has a master cylinder 32 with an axially movable main piston 34, 30 and a lower cylinder with an axially movable lower piston 35, the master cylinder being divided by a main piston into a primary chamber 36 communicating with a fluid passage 36 3 via line 41, and a secondary chamber 37 which communicates with the nest cavity via line 42. The master cylinder is further connected to a line 43, by means of which it is possible to bring either the primary or secondary chamber into contact with the closed chamber according to the operation of the main piston. The main piston is located on the left side inside the master cylinder when the fluid pressure is greater than the pressure inside the housing cavity to communicate with the fluid passage and the closed chamber in the primary chamber and when the pressure inside the housing cavity is greater than the fluid pressure, the main piston is on the right side of the housing cavity. to communicate the closed chamber with each other in the secondary chamber.

On the other hand, the lower cylinder 33 is divided by a lower piston 35 into a control chamber 38 which communicates with the housing cavity via a line 42 as well as a secondary chamber 37 and a conduit chamber 39 which communicates with the outside air or the primary chamber through an opening 44 therein. The lower piston is forced-20 towards the control chamber by means of a compression spring 45.

The strength of this compression spring is chosen to allow the lower piston to operate, i.e. to move to the left in the figure, when the pressure P1 within the housing cavity reaches a predetermined level P31 greater than predetermined limits, and the lower piston diameter d2 in the lower cylinder is selected. that it is larger than the diameter d ^ of the main piston in the master cylinder.

As the pressure inside the housing cavity increases beyond the allowable limits and reaches a predetermined level £ 3 '»30 the lower piston therefore moves to the left in the figure against the action of the compression spring and comes into contact with the main piston and uses it to connect the closed chamber 9 79613 2 to the primary chamber. with the liquid channel.

When the primary side fluid pressure is greater than the housing cavity internal pressure of the master cylinder main piston 34 MOVE-5 TYY therefore be above the ball valve to the left of the figure on the primary fluid passing the pressure in a closed chamber as shown in Figure 3. On the other hand, since the lower piston is on the right-hand side, the lower cylinder blades are subjected to a self-compressing force π 2 2 10 - (D_ - D.) (P - P_) on the rear surface of the seat stop and

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a valve seat comes into close contact with the ball, wherein on the primary fluid is sealed.

Next, the receptacle cavity 10 when the internal pressure P L is greater than the fluid pressure P2 of the secondary side fluid channel 3, 15 of the master cylinder main piston 32 moves to the right in Figure 34 to bring the receptacle cavity in connection with a closed chamber 13 as shown in Figure 4. On the other hand, the lower piston 35 is forced to the right in the figure by means of a compression spring 45 and held in that position as long as the above pressure P_ is within predetermined permissible limits so that the self-compressing force - (D - D,) (P_ - P_) acts 4 1 jj ^ istukanpidäkkeen rear surface, wherein the secondary fluid is sealed.

However, when the pressure inside the housing cavity 10 abnormally increases beyond the predetermined allowable limits and reaches a predetermined level P 1, this pressure acts on the control chamber 38 as shown in Fig. 5, which pressure, as previously noted, moves the lower piston to the left against the compression spring 45. 30 wherein its piston rod to move the main piston 34 to the left 10 73 602 so that the sealed chamber 13 is connected to the secondary-side fluid channel 3 in the main cylinder 32 when the self-π compressive force February 2 ~ D | ) ^ 3 '“affects the seat stop, which moves backwards towards the rear.

As a result, five receptacle cavity into communication with the secondary side of the fluid channel and the internal pressure of the receptacle cavity is discharged to the secondary side in order to prevent an abnormal increase in pressure.

Receptacle cavity is thus in connection with the secondary fluid, the chicken 1 with the van 10, and the internal pressure decreases yhfäkkiä, so installing a choke valve in connection with the check valve 51 to line 42, as shown in Figure 6, valve operation can be stabilized.

Although in the above description may receptacle cavity 15 with the secondary side connection fluid passage when the internal pressure reaches a certain level, it can be placed in communication with the fluid on the primary channel.

According to the ball valve of the present invention, as the pressure inside the housing cavity increases abnormally, the housing cavity is brought into contact with the closed chamber by applying this pressure through a diverter valve. non-25 normal growth can be prevented without any direct relationship to the capacity of the diverter valve and piping. The valve of the present invention is thus advantageous in that it can be used with a reversing valve and piping of the same capacity, regardless of the inner diameter 30 of the valve.

Claims (1)

11 79602 Claim: A ball valve with a housing (1); a movable spherical closure member (2) for opening and closing the fluid passage (3) in the housing (1); an annular seat retainer (4) arranged in the housing (1) opposite the spherical closure member (2) to surround the fluid passage (3); an annular valve seat (6) attached to the seat stop (4) opposite the spherical closure member (2); a first 0-ring (8, 11) located at a point whose outer diameter (D2) is larger than the sealing point diameter (D1) of the valve seat (6) on the outer circumferential surface of the seat stop (4) where the seat stop (4) is in sliding contact -sa with the inner wall surface of the housing (1); a second O-ring (12) positioned at a point with a sealing diameter (D3) smaller than the sealing point diameter (D1); a closed chamber (13) formed between the inner wall surface of the housing (1) and the rear surface of the seat stop (4) between the first (8, 11) and the second O-ring (12); and a diverter valve (31) having a master cylinder (32) divided by an axially movable main piston (34) into a primary chamber (36) communicating with the fluid passage (3) and a secondary chamber (37) communicating with the fluid channel (3). with the main cavity (10), wherein the main piston (34) is arranged to communicate with the fluid passage (3) and the closed chamber (13) through the primary chamber (36) when the fluid pressure (Ρχ) in the fluid passage (3) is higher than the housing cavity (10). ) internal pressure (P3) and to bring the housing cavity (10) and the closed chamber (13) into contact with each other when the internal pressure (P3) of the housing cavity (10) is higher than the fluid pressure (Ρχ) prevailing in the fluid passage (3), characterized in (31) further comprises a lower cylinder (33) divided by an axially movable lower piston (35) into a guide chamber (38) communicating with the housing cavity (10) as well as a secondary chamber (37) and a conduit chamber (39) communicating with to the outside air 12 79602 or to the primary chamber (36), the lower piston (35) being forced towards the control chamber (38) by a compression spring (45) and displaced against the compression spring (45) when the internal pressure (P3) of the housing cavity (10) reaches a predetermined level (P31). ) for communicating the closed chamber (13) with the fluid passage (3) through the primary chamber (36), the pressure reducing force acting on the seat retainer (4) to connect the housing cavity (10) directly to the fluid passage (3) past the annular valve seat (6) through the space formed between the annular valve seat (6) and the movable spherical closing member (2). claim; Valves with a valve (1)? that the rotating body (2) for operation and operation of the air supply (1) is connected to the air duct (3); in the form of a ring (4), which can be connected to a valve (1) without means of a tongue-and-groove body (2) for the use of the valves (3); ett ringformigt valilsäte (6) # vilket är fixerat vid setupeshallaren (4) mitt emot det kulformiga tillslutningsorganet (2); en första 0-ring (8, 11), vilken är placerad i en punkt vars ytterdiameter (D2) är större än ventilsätets (6) tätningspunktsdiameter (Di) head of the safety case (4) of the outer periphery, of the adjustable temperature (4) star i glidkontakt med ventilhusets (1) inre väggyta; and the O-ring (12) is shown as a placeholder and a point, the diameter (D3) and the diameter (D); in the chamber (13), the cells are shown as melan ventilatorsets (1) in which they are mounted and adjusted (4) in a row (8, 11) and in the 0-rings (12); with the valve (31), with the cylinder (32), with the cylinder and the axle of the plunger (34) being mounted in the primary chamber (36), with the communicator with the valve