RU181161U1 - Axial Flow Control Valve - Google Patents

Abstract

A utility model relates to pipe fittings designed to control flow or pressure on discharge pipelines. The axial flow control valve comprises a housing (1) with inlet (2) and output (3) nozzles and a cowl (4) located inside the housing (1) to form an annular channel (5). The outlet part of the fairing (4) is covered by a separator (6) perforated with holes (7). The separator (6) is rigidly connected to the seat (8). The seat (8) is fixed in the outlet pipe (3). In the saddle (8) is placed with the possibility of axial movement inside it of the piston (10). The piston (10) is mounted on the driven rail (15) of the helical gearing (14) of the rack mechanism. The drive rod (13) is connected to the actuator. The helical cavity cavities (14) and the end face of the drive rod (13) are isolated from the pressure of the working medium. The sealant comprises a bearing ring (30) made of a material having a low coefficient of friction, which is mounted motionless in the annular groove (29). The groove (29) is made on the inner surface of the outlet part of the fairing (4) connected to the separator (6) in front of the radial holes (7), between two cuffs (31) and (32). Cuffs (31) and (32) are placed opposite each other on both sides of the bearing ring (30). It is possible double-sided valve tightness in the closed position and the exclusion of mechanical impurities on the sealing surface of the cuffs, which increases the reliability of the design of the axial flow control valve. 2 ill.

Description

The utility model relates to pipe fittings designed to control flow or pressure on injection pipelines, and can be used in gas and oil pipelines to control the processes of pumping liquid and gas media under pressure.

Known axial flow valve, consisting of a rigidly interconnected outer casing with a saddle and an inner casing, forming a rectified axisymmetric flow part, an unloaded plunger with sealing surfaces, located in the inner casing with a landing annular gap (patent RU No. 2267680 C1, IPC F16K 1 / 12, priority dated May 28, 2004, published January 10, 2006).

The disadvantage of the valve is the complexity of the design of the shut-off element equipped with a sealing metal bellows, the maintenance of which requires additional maintenance of the bypass line equipment. Violations and malfunctions in the bypass line and bellows lead to insufficient valve tightness, especially at high pressures of the controlled medium. In addition, the presence of a bypass line leads to an increase in the number of seals in the valve, which reduces its reliability.

Known axial control valve containing a housing with inlet and outlet nozzles and a cowl located inside the housing with the formation of an annular channel, the output of which is blocked by perforated holes with a separator (sleeve), rigidly connected to the seat fixed in the outlet pipe, and placed inside it with the possibility of axial displacement piston mounted on a driven rack and pinion rack, the leading rod of which is connected to the drive, the helical cavity cavities and the end face of the drive rod the pressure of the working medium, and the cavity of the end face of the driven rod is in communication with the piston cavity, a combined seal including a ring of material having a low coefficient of friction (patent RU No. 165850 U1, IPC F16K 1/12, F16K 47/08, F16K 39/04 , priority of September 16, 2015, published on November 10, 2016).

A disadvantage of the known valve is:

the presence of an annular groove on the outer cylindrical surface of the piston negatively affects the operation of the seals. In the closed position, the seals are in contact with the piston, which ensures the tightness of the valve, however, when the piston moves, the seals come out of contact with the outer cylindrical surface of the piston due to the groove, forming an enlarged annular channel between the annular groove of the outer surface of the piston and the inner surface separator (sleeve). Seals during an open-closed cycle absorb the additional load from the effort of preloading the piston at the moment of transition from a machined outer surface of the piston to a non-machined one, which significantly reduces the reliability of the valve sealing assembly. It is also likely that during the transition from a non-working (not pre-loaded) to a working (pre-loaded) state, the seals may incorrectly stand up or pop out of the annular groove in the separator (sleeve), as a result of which the tightness will not be ensured. Also, due to the enlarged annular channel between the piston and the separator (sleeve), the sealing surface of the seals can be destroyed by the flow of the working medium, which will lead to a lack of tightness of the seal. The presence in the working medium of mechanical impurities will also affect the increased destruction of the sealing surface of the seals;

the execution on the inner part of the separator (sleeve) on each side of the perforated holes contributes to the formation of an on-going error of misalignment due to the fact that the housing has two seating surfaces for installing the sleeve and, accordingly, two seating surfaces on the outside of the sleeve. The geometric location of the liner in the housing will be determined by the indicated landing surfaces, taking into account the error and tolerances of the forms of their manufacture. However, the annular grooves in the sleeve for installing the seals are performed without taking into account the error in the sizes and tolerances of the shapes of the housing seating surfaces, as a result of which an indirect error is formed, which affects the geometric arrangement of the seals relative to the housing. This in turn affects the tightness of the valve, the forces that must be applied to move the piston in the sleeve, and accordingly the reliability of the valve.

The task to which the claimed utility model is directed is to increase the reliability of the design of the axial flow control valve.

The problem is solved in that in the axial flow control valve containing a housing with inlet and outlet nozzles and a cowl located inside the housing to form an annular channel, the outlet of which is blocked by a perforated separator, rigidly connected to the saddle fixed in the outlet, and placed inside with the possibility of axial movement of the piston, mounted on a driven rack and pinion rack, the leading rod of which is connected to the drive, helical cavity cavities and the ends of the leading rod are isolated from the pressure of the working medium, and the cavity of the end face of the driven rod is in communication with the piston cavity, a sealing assembly including a fixed ring made of a material having a low coefficient of friction, according to a utility model, the sealing assembly is placed in an annular groove made on the output outlet surface part of the fairing connected to the separator in front of the radial holes and equipped with two cuffs mounted opposite to each other on both sides of the ring, low friction guide with established in each wiper to provide a double-sided sealing valve in closed position and exclude ingress of solids on the sealing surface of the cuff.

Placing the sealing assembly in an annular groove made on the inner surface of the outlet part of the fairing connected to the separator in front of the radial holes and supplying it with two cuffs mounted opposite to each other on both sides of the ring having a low coefficient of friction, with a wiper installed in each of them, eliminates the on-going error of the annular grooves for seals, provides the possibility of two-way valve tightness in the closed position due to the position of two collars between the piston and the housing, and entering an exception mechanical impurities on the sealing surface of the cuff, thereby increasing the reliability of the design of axial flow regulating valve.

The installation of a bearing ring between two cuffs provides centering of the piston relative to its axis of motion, reduces the load perceived by the cuffs and thereby reduces their wear, and due to the low coefficient of friction, reduces the forces required to move the piston.

The bearing ring also serves as a wiper, eliminating the ingress of mechanical impurities contained in the medium onto the sealing surfaces of the cuffs.

Also, this design of the sealing assembly ensures constant contact between the sealing lips and the piston. The absence of grooves on the piston provides a constant extrusion gap between the seal and the piston, which is the main factor guaranteeing tightness. The location of the seals in the fairing of the housing allows you to exclude from the design of the seal between the outer surface of the separator and the inner surface of the housing, which in turn increases the reliability of the valve.

Axial flow control valve is illustrated by drawings where:

in FIG. 1 shows a General view of the axial flow control valve, longitudinal section.

in FIG. 2, view A in FIG. 1, a sealing assembly is shown located in the housing in front of the separator. In the drawings, the positions indicated:

1 - case

2 - inlet pipe

3 - outlet pipe

4 - fairing

5 - passage ring channel

6 - separator

7 - radial holes in the separator

8 - saddle

9 - clamping sleeve

10 - piston

11 - piston cavity

12 - holes in the piston end

13 - the leading stem helical gearing

14 - helical gearing

15 - driven helical gear rack

16 - guide bush

17 - vertical hole in the guide sleeve

18 - horizontal hole in the guide sleeve

19 - hole in the housing

20 - movable seal

21 - stationary seal

22 - helical cavity

23 - sealing element

24 - sealing element

25 - fairing

26 - seal

27 - channel

28 - stuffing box

29 - ring groove

30 - the ring bearing

31 - cuff

32 - cuff

The axial type control valve comprises a housing 1 with inlet 2 and outlet 3 nozzles and a cowl 4 forming an annular passage channel 5 (Fig. 1). At the outlet of the channel 5, a separator 6 with radial holes 7 is installed. The separator 6 is fixed by a saddle 8 and a pressure sleeve 9 in the outlet pipe 3. A piston 10 is mounted inside the separator 6 with the possibility of axial movement. The cavity 11 of the piston 10 communicates with the cavity of the outlet pipe 3 by means of holes 12, made at the end of the piston 10. The mechanism for moving the piston 10 includes a rack and pinion mechanism comprising a drive rod 13 cooperating by means of helical gearing 14 with a driven rack 15. Moving the staff 15 of the helical gearing 14 about bounded by a guide sleeve 16 fixed in the cavity of the fairing 4. Two mutually perpendicular holes are made in the sleeve 16: a vertical hole 17 and a horizontal hole 18. The vertical hole 17 is made coaxially with the hole 19 made in the housing 1, in which the lead rod 13 is located. a driven rail 15 is located in the hole 18. The hole 18 between the movable seal 20 and the stationary seal 21 and the cavity of the holes 17 and 19 form a helical cavity 22. The cavity 22 is isolated by sealing elements 23 and 24 from the pressure of the working medium. The hole 18 from the free end side of the driven rack 1 is isolated by a fairing 25 and a seal 26 from the cavity of the inlet pipe 2 and is connected by channels 27 and the channel of the fairing 4 with the piston cavity 11. At the top of the hole in the housing 19 there is a sealing stuffing box 28. To ensure two-way valve tightness in in a closed position on the inner surface of the outlet part of the fairing 4, connected to the separator 6 in front of the radial holes 7, an annular groove 29 is made. A groove bearing 3 is installed in the groove 29 0, having a low coefficient of friction (Fig. 2). The sliding bearing ring 30 is provided with two cuffs 31 and 32, centers the piston 10 relative to the axis of movement, reduces the load perceived by the cuffs 29 and 30 and, due to the low friction coefficient, reduces the forces required to move the piston 10. The cuffs 31 and 32 are installed opposite each other both sides of the bearing ring 30. The cuff 31 provides valve tightness in the closed position of the shutter relative to the pressure of the medium from the side of the valve inlet 2. Cuff 32 provides valve tightness in the closed position of the shutter relative to the pressure of the medium from the side of the outlet pipe 3 of the valve. In this case, the cuffs 31 and 32 exclude the ingress of mechanical impurities on their sealing surfaces. The valve operates as follows.

The adjustable medium enters the inlet pipe 2 and, passing through the annular channel 5 formed by the housing 1 and the fairing 4, enters the outlet pipe 3 through the openings 7 of the separator 6. If necessary, reduce the volume of the controlled medium (when closing the valve), the piston 10 by means of the driven rack 15 and the leading rod 13 of the helical gearing 14, is shifted by the drive to the right position, blocking the openings 7 of the separator 6. The volume of the passing controlled medium is determined by the number of open holes 7 in the separator 6. When fully closed, Verstov separator valve is closed.

The valve is opened by a drive that sets the motion of the leading stem 13, connected by helical gearing 14 to the driven rack 15, which moves the piston 10 to the left position. The pressure of the working medium in the cavity 11 of the piston 10 is equal to the pressure in the outlet pipe 3 due to the presence of holes 12 at the end of the piston 10 communicating these cavities. The piston is completely unloaded.

The pressure of the working medium in the hole 18 of the guide sleeve 16 formed for the end face of the driven rack 15 is equal to the pressure in the cavity 11 of the piston 10 due to the presence of channels 27 and the fairing channel 4 communicating these cavities, and, hence, the pressure in the cavity of the outlet pipe 3. Stem 13 is completely unloaded.

The cavity 22 of the helical gearing 14 is isolated from the pressure of the working medium by means of sealing elements 20, 21, 23, 24, due to which the force from the pressure of the working medium when the piston 10 moves does not act on the end face of the drive rod 13.

The tightness of the cavity 22 helical gearing 14 relative to the external environment is provided by the sealing gland unit 28.

A bearing ring 30 installed between the two cuffs serves as a centering body of the piston 10 relative to the housing, and also as a low-friction sliding bearing, provides an unloading of forces from the cuffs 31 and 32, thereby reducing their wear. Cuffs 31 and 32 reduce the ingress of mechanical impurities on the sealing surfaces of the seals contained in the medium. Provides constant contact of the sealing cuffs 31 and 32 with the piston 10. The absence of grooves on the piston 10 provides a constant extrusion gap between the seal and the piston 10, which is the main factor guaranteeing tightness. The transfer of the seals to the fairing 4 of the housing 1 allows to exclude from the design the seal between the outer surface of the separator 6 and the inner surface of the housing 1, which in turn increases the reliability of the valve.

Thus, the result of an improvement in the design of the axial flow control valve is an increase in the reliability and durability of the valve design.

Claims (1)

Axial flow control valve, comprising a housing with inlet and outlet nozzles and a cowl located inside the housing to form an annular channel, the outlet of which is blocked by a perforated separator, rigidly connected to the seat fixed in the outlet, and the piston is axially moved inside mounted on a driven rack and pinion rack, the leading rod of which is connected to the drive, the helical cavity and the end of the leading rod are isolated from pressure of the working medium, and the cavity of the end face of the driven rod is in communication with the piston cavity, an annular groove with a ring made of a material having a low friction coefficient, characterized in that the annular groove is made on the inner surface of the outlet part of the fairing in front of the separator, while the ring with a low coefficient of friction has the properties of a sliding bearing with the possibility of reducing the forces required to move the piston, and is placed between two cuffs installed prot vopolozhno each other on either side of the bearing-ring to provide a double-sided sealing valve in closed position and exclude ingress of solids on the sealing surface of the cuff.

Images