RU2243438C2 - Double-acting high pressure ball cock - Google Patents

Abstract

FIELD: valving.

SUBSTANCE: ball cock comprises housing with horizontal inlet and outlet units for fluid flow and vertical inner bore (throat). The units are interconnected through the separating space. The throat receives driving shaft provided with a control handle. The housing receives the ball cut-off member provided with through longitudinal opening and two movable seat-seals flexibly loaded with pressing devices. The seat-seals are arranged on both sides of the cut-off member provided with central concave units. The units are in contact with the cut-off member throughout their surfaces. The cut-off member is mounted for permitting rotation in the vertical plane by an angle of 90^o. One seat is set in the cylindrical bore of the housing. The second seat is set in the inner cylindrical bore of the joint bushing with the sealing ring on its outer side. The bearing nut is coupled with the housing via a thread and abuts against the ring projection of the joint bushing. The vertical inner bore (throat) of the housing is step-shaped. The greater step is positioned from the side of the separating space. The bore tightly houses the antifriction coaxial cylindrical bushing-insert with the outer ring collar. The bushing-insert is mounted for permitting simultaneous contact and co-operation with the corresponding sealed surface of the driving shaft and adjusting inner surface of the control handle base. The bushing is provided with a locking member which is made of a locking flat plate and prevents the bushing against rotation. The bearing face of the ring collar conjugated with the housing is conical. The top of the conical surface points to the handle. The outer open periphery surface of the handle, which is in the atmosphere, is provided with at least one groove arranged perpendicular to the axis of rotation of the bushing. The locking plate is secured to the housing for permitting co-operation with the bushing groove.

EFFECT: enhanced reliability and safety of operation of ball cock.

3 dwg

Description

The invention relates to valve engineering and is intended for use as a locking device in pipelines transporting corrosive environments or natural gas with high pressure.

As tests and operating experience show, the reliability and life of ball valves most often and mainly depend on the reliability of the drive shaft assembly.

Known ball valve (crane), comprising a housing, two movable threaded nozzles with o-rings-saddles, a ball valve with a central passage hole, a drive shaft included in the recess of the ball valve (AS No. 1651003, class F 16 K 5 / 06, 02.08.89).

A ball valve is also known, in the case of which there is a stopper with o-rings, an axially movable sleeve that presses the rings to the stopper under the action of a union nut, and a seal that seals the sleeve relative to the body (ball valve according to SU No. 543802 A, class F 16 K 5/06, 01/25/1977).

The disadvantages of the known designs include the fact that compensation for the wear of the package of sealing elements installed in known taps in the bores of the drive shaft housings is made by axial tightening of a vertically located screw plug and an intermediate clamping sleeve compressing the package of sealing elements. Such a fairly widespread way to ensure the external tightness of the crane along the drive shaft causes great inconvenience in operation due to frequent adjustments and, in addition, differs in the characteristic instability of the external tightness mainly when the crane is operating in low ambient temperatures from minus 30 to minus 60 ° C.

In accordance with the requirements of current state standards, the external tightness of ball valves in the range of operating temperatures must be complete.

Known ball valve (crane), comprising a housing with inlet and outlet horizontal sections for the passage of the medium, communicating with each other through a cavity separating them, a drive shaft with a handle, a ball locking element with a through longitudinal hole and can be rotated in a vertical plane by 90 °, two movable, located on both sides of the locking body, elastically spring-loaded by squeezing devices of the seat-seal, one of which is installed in the cylindrical bore of the body, the other in the cylindrical bore IG Petritskaya threaded plug with an O-ring on the outer cylindrical surface (Russian patent RU 2171935, Cl. A 16 K 5/06, 10.08.2001).

The disadvantage of this design is that due to the objective necessity of using stainless steel parts in the valve during operation of the valve under load, the contact (molecular) setting characteristic of such steels occurs on the mating surfaces of the drive shaft and housing, resulting in strong nadir and as a result, increased wear of these surfaces, which is invariably accompanied by an increase in the moment required to turn the control handle, or, in the worst case, jamming it.

Another common drawback of the known technical solutions, including the above designs of cranes-analogues, is that they do not have sufficient reliability and safety for a long period of operation. So, in cases of possible loosening or loss by external fasteners that fix the axial position of the drive shaft in the housing, the specified tightening torques (for example, due to vibrations or self-oscillations of the elements of the working medium wiring system), the crane drive shaft is squeezed out of the landing nests, which causes, at first, partial, and then complete depressurization of the stopcock with all the ensuing consequences.

The closest in technical essence (prototype) to the claimed invention is a gas ball valve (US No. 5082246, CL F 16 K 5/06, 1991). The known ball valve contains the greatest number of similarities with the claimed valve, namely: both devices are a ball valve, each of which contains a housing with horizontal inlet and outlet sections for the passage of the medium, communicating through the cavity separating them, and a vertical internal bore (neck) in which the drive shaft is located with the control handle base fixed thereon, a ball locking element with a through longitudinal hole and the possibility of rotation in a vertical plane at an angle of 90 °, two movable saddles-seals located on both sides of the locking body with central concave sections that are completely in contact with the surface of the locking body, one saddle is installed in a cylindrical bore of the housing, the other in a cylindrical bore of a movable sleeve with a sealing ring on the outer cylindrical surface.

The advantage of the known crane is that it does not provide for the use of external fasteners to balance the drive shaft from the pressure forces of the working medium. The drive shaft, unlike analog cranes, is installed in the vertical bore of the body from the inside through the separating cavity and abuts against the end wall of the vertical bore with its outer annular collar, which accepts the main load from the action of pressure forces of the working medium. The design is distinguished by safety and guaranteed external tightness along the drive shaft, but does not exclude the disadvantage inherent in the analogue described above according to RF patent RU 2171935.

A high probability of “tightening” or jamming of the control during operation, leading to failure, significantly reduces the reliability of the crane and makes it unrepairable.

The technical task of the invention is to solve the following problems:

- reduction of friction and the exclusion of molecular seizure of contacting surfaces of the drive shaft and housing in conditions of insufficient lubrication,

- increasing the wear resistance of the contacting surfaces of the drive and, therefore, increasing the resource and external tightness of the crane in a wide operating range of pressures and temperatures of the working medium,

- fulfillment of crane maintainability requirements,

- ensuring safety during operation.

The problem is solved in that in a ball valve containing a housing with horizontal inlet and outlet sections for the passage of the medium, communicating through the cavity separating them, and a vertical internal bore (neck), in which the drive shaft is located with the base of the control handle fixed on it, a ball locking body with a through longitudinal hole and the ability to rotate in a vertical plane at an angle of 90 °, two movable elastically loaded pressing devices of the seat-seal, located on both to the torons of the locking body with central concave sections completely in contact with the surface of the locking body, one saddle is installed in the cylindrical bore of the housing, the other in the inner cylindrical bore of the connecting sleeve with a sealing ring on the outer cylindrical surface, and a support nut mating with the housing along the threaded surface and abutting against the annular ledge of the connecting sleeve, according to the invention, the vertical internal bore (neck) of the housing is made stepped and its b the upper step is located on the side of the separating cavity, the antifriction coaxial cylindrical sleeve is sealed in the bore - a liner with an outer annular collar and the possibility of simultaneous contact and interaction with the corresponding sealed surface of the drive shaft and the mounting inner surface of the base of the control handle, while the sleeve is equipped with the housing with a fixing element in the form of a lock flat plate, and the supporting end surface mating with the housing the annular collar is made conical, with the apex of the cone directed toward the handle, and at least one groove perpendicular to the axis of rotation of the sleeve is formed on the outer open peripheral surface of the sleeve adjacent to the atmosphere, and the lock plate is rigidly fixed to the housing with the possibility of interaction with the specified groove of the sleeve.

The installation in the crane between the body and the drive shaft of an antifriction (for example, bronze) coaxial sleeve with a thrust outer annular collar from the side of the dividing inner cavity and with the possibility of its fixation from rotation prevents the setting and jamming of the joined parts, increases the reliability and service life of the crane, provides easy installation and dismantling the parts of the unit during routine and repair work.

The possibility of carrying out the invention is provided by the design of the crane shown in the drawings.

Figure 1 shows a double-acting ball valve for high pressures in the open position, General view, section.

Figure 2 shows a General view, section of a ball valve in the closed position.

Figure 3 shows a section a - a of figure 1.

The ball valve (figure 1) contains a housing 1 with horizontal inlet (conditionally) 2 and outlet (conditionally) 3 sections for the passage of the medium, communicating through the cavity 4 separating them, and a vertical internal bore (neck) 5, in which the drive shaft 6 with the base 7 of the control knob 8 fixed on it, a ball locking member 9 with a through longitudinal hole 10, two movable elastically loaded pressing devices 11 of the seat-seal 12 located on both sides of the locking member 9, one saddle is mounted in a cylindrical nd bore 13 of the housing 1, the other - the internal cylindrical bore of the movable connecting piece 14 with a sealing ring 15 on the outer cylindrical surface. At the end of the connecting sleeve 14 abuts the support nut 16, conjugated with the housing 1 on the threaded surface.

The vertical internal bore (neck) 5 of the housing is stepped, its large step 17 is located on the side of the separating cavity 4, and the anti-friction coaxial cylindrical insert sleeve 18 with the outer annular collar 19 is tightly sealed in the bore 5 with the drive sleeve 18 on the inner surface in contact with the drive the shaft 6, and on the outer surface - the base 7 of the control handle 8. The insert sleeve 18 is provided with a locking element in the form of a locking flat plate 20 interacting with the groove groove 21 (Fig. 3), nennym the open peripheral surface of the hub perpendicularly to its axis. The lock plate 20 is rigidly connected to the housing 1 using two fixing screws 22. The supporting end surface of the annular collar 19 (figure 1) is made conical. The base 7 with the control handle 8 is rigidly connected to the drive shaft 6 using a nut 23.

Ball valve works as follows.

The ball valve opens (see figure 1) or closes (see figure 2) the flow of the working medium by turning the ball locking element 9, which is carried out by turning the drive shaft 6 with the handle 8 at an angle of 90 degrees. In the “open” position, the passage openings of sections 2 and 3 of the housing 1 are respectively aligned with the passage hole 10 of the locking member 9, and the working medium passes through the valve. In the “closed” position, the shut-off element 9 closes the path to the working medium, and the elastically deformed system, consisting of a clamping device 11 and the ball shut-off element 9, prevents the leakage of the working medium.

The most difficult operating modes for a ball valve are the high pressure shutoff mode and the “standby” mode, when the valve shut off for a long time is exposed to high pressure and ambient temperature. The working load in this case, perceived by the ball locking element 9, is transmitted through radially directed forces to the spherical surface of the seat-seal 12. Due to the fact that the materials for the manufacture of seat-seals are mainly polyamide materials with high values of friction coefficients, the values increase significantly moments necessary for turning the control shaft, and with it the radial loads of the drive shaft on the mounting surface of the housing. Ultimately, the wear of interacting surfaces increases, which largely determines the life of the crane.

In the proposed design of the ball valve, due to the installation of an antifriction (for example, bronze) coaxial sleeve 18, it was possible to eliminate the “setting” and jamming of the drive shaft 6, significantly reduce the turning force of the control handle 8, and the locking from turning in the sleeve body 18 with a lock plate 20 is guaranteed to ensure the sliding of the drive shaft and its seal relative to the sleeve with lower angular velocities and wear.

Thus, the ball valve, made according to the invention, allows you to create a valve with increased service life and high reliability, with almost unlimited ability to carry out high-tech repair and restoration work during the assigned resource, which is confirmed by the results of factory tests and operation.

Claims (1)

Double-acting ball valve for high pressures, comprising a housing with horizontal inlet and outlet sections for the passage of the medium, communicating through the cavity separating them, and a vertical internal bore (neck), in which the drive shaft is located with the control handle base fixed thereon, a ball locking element with a through longitudinal hole and the ability to rotate in a vertical plane at an angle of 90 °, two movable elastically loaded clamping devices of the seat-seal, located on both them to the sides of the locking body with central concave sections that are completely in contact with the surface of the locking body, one seat is installed in the cylindrical bore of the housing, the other in the inner cylindrical bore of the connecting sleeve with a sealing ring on the outer cylindrical surface, and a support nut mating with the housing along the threaded surface and abutting against the annular protrusion of the connecting sleeve, characterized in that the vertical inner bore (neck) of the housing is made stepwise and its large step is located on the side of the separating cavity, the antifriction coaxial cylindrical insert sleeve with an outer annular collar is sealed in the bore with the possibility of simultaneous contact and interaction with the corresponding sealed surface of the drive shaft and the mounting inner surface of the control handle base, while the sleeve is provided with a protector against rotation in the housing with a fixing element in the form of a locking flat plate, and the end face mating with the housing the ring shoulder is made conical with the apex of the cone directed toward the handle, and at least one groove perpendicular to the axis of rotation of the sleeve is formed on the outer open peripheral surface of the sleeve adjacent to the atmosphere, and the lock plate is rigidly fixed to the housing with the possibility of interaction with the specified groove of the sleeve.

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