RU2738990C1 - Cryogenic shutoff plunger pipeline valve - Google Patents

Abstract

FIELD: valves.

SUBSTANCE: present invention relates to valve industry, in particular to shutoff valves used in cryogenic low-temperature fittings, and invention is intended for shutting off flow of cryogenic gaseous and liquid media with temperature from minus 70 °C to minus 196 °C with certain tightness. Cryogenic shutoff plunger valve comprises housing with inlet and outlet branch pipes, stand with insulator arranged inside, handwheel fitted on rod, which is coaxially installed in upper cover, between rod and upper cover there is a rod seal, seal rod is arranged in series from below up collar, spring support, spring and chevron seal resting in upper part in lower projection of tightening nut. Between the plunger and the upper cover there is an internal seal, between the post and the plunger there is an average seal and a guiding ring, between the post and the upper cover there is an external seal. Insulator is made in the form of a set of cylindrical elements arranged one above the other, at the ends of which there are circular grooves communicating with each other through vertical longitudinal channels, wherein axially cylindrical hollows are made at cylindrical element ends at annular grooves. At that, said insulator is arranged in cylindrical case.

EFFECT: proposed design of cryogenic shut-off plunger valve has high sealing parameters of seals that are not in contact with liquid phase of cryogenic medium, prevents ingress of solid particles into elements of insulator and seals, provides simplicity of assembly-disassembly during production and maintenance.

1 cl, 1 dwg

Description

The proposed invention relates to fittings, in particular, to stop valves used in cryogenic low-temperature fittings, and the invention is intended to shut off the flow of cryogenic gaseous and liquid media with a temperature from minus 70 ° C to minus 196 ° C with a certain tightness.

Known control valve company Parcol [http://www.parcol.com/docs/1-6940_Cryo_GB.pdf] containing a housing, with inlet and outlet pipes, a rack with an insulator placed inside, a steering wheel mounted on a rod, which is coaxially mounted in the upper a disc spring is located between the top cover and the insulator.

The disadvantages of this valve are the low sealing parameters of the seals, which are in contact with the liquid phase of the working media. Due to the fact that the glass transition temperature of the amorphous areas of the materials from which the cuffs are made is minus 100 ° C ... 120 ° C (GOST 10007-80, Appendix 1), the cuffs lose their elasticity and sealing properties. This valve has an internal unloading system but does not have a filter element to protect the seals from particulate matter.

Closest to the proposed invention is a manually operated cryogenic shut-off bellows valve of the AMK 331 series [http://nporeg.ru/images/new_katalogi/Katalog-Kriogennaya-armatura-NPO-Regulyator.pdf].

This valve contains a body with inlet and outlet nozzles, a rack with an insulator placed inside, a steering wheel mounted on a stem, which is coaxially installed in the upper cover, with a wiper installed in its upper part. A stem seal is installed between the stem and the top cover; a bearing is placed in the upper part of the valve to ensure rotation of the stem, the stem interacts with the plunger in the lower part, and a seat is installed in the valve body.

The disadvantages of this valve are the low sealing parameters of the seals, which are in contact with the liquid phase of the working media. Due to the fact that the glass transition temperature of the amorphous areas of the materials from which the cuffs are made is minus 100 ° C ... 120 ° C (GOST 10007-80, Appendix 1), the cuffs lose their elasticity and sealing properties. This valve has an internal unloading system, but it does not have a filter element to protect the seals and isolator from particulate matter. In addition, this valve is quite difficult to carry out the assembly and disassembly operations required for its production and maintenance.

The objective of this invention is to provide a cryogenic stop-type plunger globe valve having high sealing parameters of seals that are not in contact with the liquid phase of the cryogenic medium, preventing the ingress of solid particles into the insulator and seal elements, ensuring ease of assembly, disassembly during production and maintenance.

The task is achieved by the fact that in a cryogenic shut-off plunger straight-through valve containing a body with inlet and outlet nozzles, a rack with an insulator placed inside, a steering wheel mounted on a rod, which is coaxially installed in the upper cover, with a wiper installed in its upper part, between the rod and a stem seal is installed with the upper cover, a bearing is placed in the upper part of the valve to ensure the rotation of the stem, the stem interacts with the plunger in the lower part, a seat is installed in the valve body, the stem seal is a cuff, a spring support, a spring and a chevron seal placed in series from bottom to top, resting in the upper part in the lower protrusion of the clamping nut, the bearing is installed in the upper cavity of the plunger between its bottom and the lower end of the rod, made in the form of a cylinder with a spherical lower surface, holes with a broken axis are made in the plunger, connecting its lower cavity with the cavity of the upper cover, between the plunger and the upper it has an internal seal with a cover, a middle seal and a guide ring are installed between the column and the plunger, an external seal is placed between the column and the top cover, the upper cover rests on the lower end on a lock nut installed on the outer surface of the column, in the lower part, on the outside the column contacts with a glass, on which the removable flange of the rack mount rests, an external seal of the glass is placed between the glass and the body, an insulator is located coaxially in the internal cavity of the rack, supported by the lower end on a nut in which a filter element is installed, and in the lower part of the insulator from its outer side it is coaxially located a cylindrical insert, between which a cup seal and a guide ring are installed, the insulator is made in the form of a set of cylindrical elements located one above the other, at the ends of which annular grooves are made, communicating with each other through vertical longitudinal channels, and coaxially with the ring Cylindrical-conical cavities are made to the grooves at the ends of the cylindrical elements, and the insulator is placed in a cylindrical casing.

The cryogenic shut-off plunger straight-through valve contains a housing 1 with inlet 2 and outlet 3 nozzles, a post 4 with an insulator 5 located inside, a handwheel 6 (not shown in Fig. 1) mounted on a rod 7, which is coaxially installed in the upper cover 8, with an installed in its upper part with a wiper 9.

Between the rod 7 and the upper cover 8, a rod seal is installed, which is a cuff 10, a spring support 11, a spring 12, and a chevron seal 13, which rests in the upper part on the lower protrusion of the clamping nut 14, placed in series from the bottom upwards.

To ensure the rotation of the stem 7, a bearing 15 is placed in the upper part of the valve, which ensures the dissipation of the transfer axial force along the plunger 16. In the lower part, the stem 7 interacts with the plunger 16, a seat 17 is installed in the valve body 1. The seat 17 is screwed into the body with a seal 27 plane along the plane (metal - metal).

The bearing 15 is installed in the upper cavity of the plunger 16 between its bottom and the lower end of the rod 7, made in the form of a cylinder with a spherical lower surface.

In the plunger 16, holes 18 with a broken axis are made, connecting its lower cavity with the cavity of the upper cover 8.

An inner seal 19 is placed between the plunger 16 and the top cover 8. Between the post 4 and the plunger 16, there is a middle seal 20 and a guide ring 21. An external seal 22 is installed between the post 4 and the top cover 8.

The lower end of the upper cover 8 rests on the lock nut 23 installed on the outer surface of the rack 4, in the lower part, from the outside, the rack 4 contacts the sleeve 24, on which the removable flange of the rack 4 rests. The lock nut 23 prevents the upper cover 8 from unwinding when vibrations occur.

An insulator 5 is coaxially located in the inner cavity of the rack 4, which is supported by its lower end on a nut 25 in which a filter element 26 is installed.

In the lower part of the insulator 5, on its outer side, a cylindrical insert 28 is coaxially located, between which a cup seal 29 and a guide ring 30 are installed between the cup 24 and the guide ring 30. The guide ring 30 centers the plunger 16 and the cylindrical insert 28, thereby protecting the surfaces from scoring during translational movement.

The insulator 5 is made in the form of a set of cylindrical elements 31 located one above the other, at the ends of which there are annular grooves 32 communicating with each other through vertical longitudinal channels 33, and coaxially with the annular grooves 32 on the ends of the cylindrical elements 31 are cylindrical-conical cavities 34. Insulator 5 placed in a cylindrical casing 35. Between the nozzle 24 and the body 1 there is an external seal of the nozzle 36.

Washer 37 and nut 38 are installed on the top cover 8 of the valve, with which any actuator can be fixed within the framework of its design and application.

Cryogenic shut-off plunger globe valve works as follows.

In the closed position, the movement of the cryogenic medium through the valve does not occur. In this case, the flow of the cryogenic medium (liquid phase) with a temperature of minus 196 ° C enters through the inlet pipe into the inner cavity of the housing 1.

When the liquid cryogenic medium moves upwards in the middle part of the insulator 5, the liquid phase is converted into a gaseous one (in the middle part of the insulator, the temperature of the gas phase is minus 100 ° C). Having reached the cavity of the upper cover 8, the gas expands due to temperature transformation, and the following processes occur:

• gas presses on the collar 10, ensuring the tightness of the plunger;

• the gas presses on the chevron seal 13, ensuring the valve stem tightness against the external environment;

• due to volumetric expansion, the gas presses through the vertical longitudinal channels 33 of the insulator 5 in the direction opposite to the flow of the cryogenic medium, thereby creating a gas cushion, which in turn additionally protects the upper part of the valve with elastic seals (collar 10, chevron seal 13) from freezing (t≤minus 70 ° С).

In order to protect the seals from solid particles, a filter element 26 is placed in the flow path, passing through which the flow is cleaned of solid particles and enters the vertical longitudinal channels 33 of the insulator 5. In order to ensure uniform distribution of the cryogenic medium between the longitudinal channels 33 and ease of assembly of the insulator 5 on the ends of the cylindrical elements 31 are made with annular grooves 32. In order to prevent freezing of the insulator, cylindrical-conical cavities 34 are made on the ends of the cylindrical elements 31 in which air or gas accumulates.

When the valve is opened (turning the handwheel 6 with stem 7), the flow area is opened (central hole in the seat 17) and the cryogenic medium rushes into the outlet nozzle 3 of body 1. The flow area is opened by lifting the following elements: rod 7, plunger 16, insulator 5 , filter element 26, cylindrical insert 28, cylindrical cage 34.

Due to the fact that the stem seal is located in the upper part of the valve (between the stem 7 and the top cover 8), it is possible to ensure its operability by removing it from the low temperature zone. In order to ensure tightness, the stem seal consists of a collar 10, a spring support 11, a spring 12 and a herringbone seal 13 located in series from the bottom upwards, supported in the upper part by the lower protrusion of the clamping nut 14. This design provides reliable sealing and a long service life even at low temperatures ... In addition, such a sequential arrangement of the stem seal allows the most rational distribution of the temperature loading of its elements.

To ensure the rotation of the rod 7 and the translational movement of the plunger 16, the insulator 5, the filter element 26, the cylindrical insert 28, the cylindrical cage 35 in the upper cavity of the plunger 16 (between its bottom and the lower end of the rod 7, made in the form of a cylinder with a spherical lower surface) is installed bearing 15. In order to ensure operability under conditions of contact with a cryogenic liquid medium, bearing 15 is raised to the maximum possible distance, where the temperature of the cryogenic medium rises to minus 70 ° C due to the transformation of the liquid phase into gaseous phase in the insulator 5.

Making holes 18 in the plunger 16 with a broken axis connecting its lower cavity with the cavity of the upper cover 8 is necessary for compact placement of the bearing 15 of the upper cavity of the plunger 16 and preventing the ingress of medium to the bearing 15.

The presence of seals located at different distances from the vertical axis of the valve (axis of symmetry of the insulator 5), which are installed between the plunger 16 and the upper cover 8 (internal seal 19), between the post 4 and the plunger 16 (middle seal 20 and the guide ring 21), between the post 4 and top cover 8 (outer seal 22) allows to ensure the tightness of the valve and evenly distribute the loads between the seals, which increases their service life, especially when working with cryogenic media.

The presence of a lock nut 23, on which the upper cover 8 rests with its lower end, makes it possible to adjust the dimensions of the cavity of the upper cover 8, in which gas accumulates, providing the pressure required to unload the valve drive. In order to ensure accessibility and ease of adjustment, the lock nut 23 is installed on the outer surface of the rack 4.

Due to the fact that the post 4 in the lower part from the outside is in contact with the nozzle 24, on which the removable flange of the post 4 is supported, simplifies assembly and disassembly of the valve (removal of the upper part from the body is provided). In addition, the presence of the cup 24 allows another seal to be placed between the cup 24 and the body (outer cup seal 36).

To ensure a seal between the inner surface of the cup 24 and the cylindrical insert 28, a cup seal 29 and a guide ring 30 are installed.

Nut 25 is needed to fasten insulator 5 and filter element 26 to cylindrical insert 28.

Due to the fact that the insulator 5 is made in the form of a set of cylindrical elements 31 located one above the other, at the ends of which there are annular grooves 32 communicating with each other through vertical longitudinal channels 33, and coaxially with the annular grooves 32 at the ends of the cylindrical elements 31 are cylindrical-conical cavities 34 it is possible to effectively increase the temperature of the cryogenic medium in the seal zone due to its transition to a gaseous state.

The placement of the insulator 5 in the cylindrical casing 35 prevents displacement of the cylindrical elements 31 and simplifies the valve assembly process.

The proposed design of a cryogenic shut-off plunger in-line valve has high sealing parameters of seals that are not in contact with the liquid phase of the cryogenic medium, prevents solid particles from entering the insulator and seals elements, and ensures ease of assembly, disassembly during production and maintenance.

Claims (1)

A cryogenic shut-off plunger in-line valve containing a body with inlet and outlet nozzles, a stand with an insulator placed inside, a steering wheel mounted on a stem, which is coaxially mounted in the upper cover, with a wiper installed in its upper part, a stem seal is installed between the stem and the upper cover, to ensure the rotation of the stem, a bearing is located in the upper part of the valve, in the lower part of the stem interacts with the plunger, a seat is installed in the valve body, characterized in that the stem seal is a cuff, a spring support, a spring and a chevron seal resting in the upper parts into the lower protrusion of the clamping nut, the bearing is installed in the upper cavity of the plunger between its bottom and the lower end of the rod, made in the form of a cylinder with a spherical lower surface, holes with a broken axis are made in the plunger, connecting its lower cavity with the cavity of the upper cover, between the plunger and the top cover is located in Internal seal, between the column and the plunger, a middle seal and a guide ring are installed, an external seal is installed between the column and the top cover, the upper cover with its lower end rests on a lock nut installed on the outer surface of the column, in the lower part, on the outside, the column contacts the glass, on which the removable flange for fastening the rack rests, an external seal of the glass is placed between the glass and the body, an insulator is located coaxially in the internal cavity of the rack, supported by the lower end on a nut in which a filter element is installed, and a cylindrical insert is coaxially located in the lower part of the insulator from its outer side , between which the cup seal and the guide ring are installed, the insulator is made in the form of a set of cylindrical elements located one above the other, at the ends of which circular grooves are made, communicating with each other through vertical longitudinal channels, and coaxially with the annular grooves on the end x cylindrical elements, cylindrical-conical cavities are made, and the insulator is placed in a cylindrical casing.

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