RU208698U1 - ULTRA HIGH VACUUM HEATED JOINT - Google Patents

Abstract

The utility model is designed to improve the reliability of maintaining the vacuum density of a heated ultra-high vacuum joint during multiple cycles of its heating and cooling. The technical result, to which the proposed technical solution is directed, is an increase in compressive stresses in the deformable part of the seal. For this, an ultra-high-vacuum heated joint is proposed, containing bearing ring elements with local sealing and restrictive surfaces, a deformable sealant installed with the possibility of force contact with local sealing and restrictive surfaces, an elastic loading system of the deformable sealant, while the deformable sealant is placed in continuous force contact with local sealing surfaces and restrictive surfaces of the bearing ring elements of the connection. 3 ill.

Description

Technical field

The utility model is designed to increase the reliability of maintaining the vacuum density of a heated ultra-high vacuum joint during multiple cycles of its heating and cooling by counteracting the spreading of the sealant from the sealing area.

State of the art

Currently, ultra-high vacuum connections are used, made in accordance with GOST 26526-85 [Vacuum equipment. Flange connections for ultrahigh vacuum systems. GOST 26526-85]. The sealing of such joints is carried out by cutting the pointed sealing protrusions of thick symmetrical flanges into the plane of the seal with the force of several pins. The flanges are centered along the outer cylindrical surface of the seal, with a length of less than 2 mm.

For small through diameters of vacuum lines (Dn 100 mm or less), these flange connections are efficient and quite easy to maintain. With an increase in the size of these devices, due to the small length of the centering surface of the seal, the installation difficulties increase. For a standard connection DN 500 mm, it was found that "a slight deviation (0.2-0.3) mm of the flange after welding from a perpendicular plane to the vacuum chamber can lead to the impossibility of creating a vacuum-tight connection" [V.V. Anashin, A.A. Krasnov, A.M. Semyonov, S.R. Sharafeev "Vacuum-tight connections for obtaining ultrahigh vacuum in vacuum systems of accelerators with wide-aperture chambers", PTE. 2019 No. 5, 134-135].

Therefore, it is important to carry out a uniform distribution of the load along the sealing contour, avoiding distortions when joining the flanges.

It has been established that loading a standard connection DN 250 mm with a relatively small torque (8 kN⋅m) leads to leakage [V.V. Anashin, A.A. Krasnov, A.M. Semyonov, S.R. Sharafeev "Vacuum-tight connections for obtaining ultrahigh vacuum in vacuum systems of accelerators with wide-aperture chambers", PTE. 2019 No. 5, p. 138].

The loss of efficiency is explained by the transfer of external stresses directly to the sealing area due to the relatively weak system of force loading of the joint and the sensitivity of this deformation scheme of the seal to the weakening of the sealing force.

To improve the accuracy of alignment of the sealed surfaces and reduce the influence of external mechanical influences on the sealing surfaces, it is advisable to carry out a rigid centering of the sealing surfaces and install a displacement compensator between the detachable connection and the vacuum line.

Studies of the reliability of sealing under conditions of thermal cycling of joints with relatively large flow sections (DN 250 mm and more), performed according to GOST 26526 - 85, showed their low performance [L.A. Filatovsky, A.S. Shuvalov, O.K. Kurbatov, S.D. Vasilchenko "New small-sized ultra-high-vacuum flange connections", Electronic engineering, Series TOPO, 1982, no. 3 (112), p. 62-64; A.S. Shuvalov "Connecting elements of ultra-high vacuum systems". Vacuum technique and technology, 1994, vol. 4, no. 4, p. 2-25; OK. Kurbatov "Physico-technical foundations of optimized high-vacuum magnetic-discharge pumps, sealing elements and devices for vacuum technological and analytical equipment of electronic technology", Abstract of the thesis for the degree of Doctor of Technical Sciences, Moscow, 2006. "Handbook of vacuum equipment and technologies", ed. . D. Hoffman, B. Singh, J. Thomas III. Translation from English, edited by V.A. Romanko, S.B. Nesterov. M. "TECHNOSPHERE", 2011, - 736 p.].

For ultra-high-vacuum heated complexes, the loss of tightness of one of the many unreliable detachable elements can lead to large financial and time costs.

The most important phenomenon leading to the occurrence of leakage during thermal cycling of large joints (DN 250 mm and more) is the impact on the sealing areas of the inevitable radial loosening stresses caused by the difference in the thermophysical properties of the materials of the sealant and sealing elements, as well as the uneven distribution of the heat flow between them.

The main reason for the occurrence of leakage in detachable joints during periodic warm-ups is a decrease in contact stress on the sealing surfaces due to the creep of the sealant from the stressed sealing area to less loaded neighboring areas.

Negative factors affecting the reliability of flange sealing are the sensitivity of many applied deformation schemes to changes in the sealing force, the short length of the working stroke, and the relatively high rigidity of the power system for loading the sealing surfaces. After the appearance of leakage in the absence of closure of the flanges, it is possible to reduce the amount of leakage by additional tightening of the connection by the power loading system. However, the new condition of the seal may not eliminate the possibility of subsequent occurrence of leakage under the influence of the above phenomena. A connection will be more reliable, in which during operation there is no increase in the interaction area and a decrease in contact stresses in the sealing area.

A known method of improving the reliability of the tightness of a detachable connection of cryogenic pipelines by preliminary joint thermal and power multiple molding of flanges and sealant [V.G. Danchenko, F.P. Savin, V.I. F16L 23/00. "Method of sealing detachable connection of cryogenic pipelines". Published 03/23/83 Bull. No. 35.]. The result of such preparation of the connection should be the installation of repeatedly pre-deformed flanges and a sealant on pipelines with the sealing of the connection, in which the contact stresses with the working value of the tightening force of the fasteners do not decrease in the subsequent time.

This method is very laborious preparation of the connection. Leads (micro warping) of the geometry of the sealing surfaces are possible after welding of the flanges on the pipelines and in the case of loading the pipeline with an external force.

In the author’s certificate of the USSR No. 291493, “Gasket for sealing fixed joints”, to reduce the possibility of displacement of the plastic seal in the closed state of the joint, its volumetric compression in a closed volume in the radial directions by internal and external elastic rings was used. Insufficient vacuum density of this compound is explained by the preservation of the surface oxide layer on the seal in the zone of deformation of the seal, the absence of a local area of sealing its compression by high contact stresses.

Uniform compression with a relatively large sealing force of a relatively thin seal in a groove-wedge joint with the same groove and wedge inclination angles also showed the impossibility of achieving a high degree of vacuum tightness of the joint [D.B. Zworykin "Issues of calculation and design of all-metal high-vacuum systems and their elements". Dissertation for the degree of candidate of technical sciences. NII MRTP, 19559].

Known proposal to improve the reliability of sealing a standard detachable connection [Vacuum equipment. Flange connections for ultrahigh vacuum systems. GOST 26526-85] elastic radial counteraction to the spreading of the sealant by performing cylindrical shells on the flanges interacting with the outer cylindrical surface of the gasket [Invention USSR Author's certificate No. 1760227]. However, the elasticity of these shells is insufficient due to the smallness of their height. The seal material, as in the standard joint design, will flow in the radial peripheral direction into the gaps located between the seal and the conical sealing surfaces, as well as the cylindrical centering surfaces of the flanges.

Another proposal for improving standard ultra-high vacuum detachable connections is the invention [A.S. Shuvalov, A.T. Alexandrova, I.F. Lobanov, B.G. Lvov, V.F. Zakrevsky, USSR Author's certificate SU No. 1180634 "Ultra-high vacuum detachable connection"]. It proposes to provide each flange with a restrictive surface located at some distance from the sealing surface. After reaching the vacuum tightness of the connection, the subsequent introduction of the sealing protrusions into the seal will be counteracted by additional interaction of the flat peripheral limiting sections of the flanges with the seal.

However, in the process of thermal cycling of the connection, the seal will necessarily creep from the most stressed sealing area to the free adjacent area, which exists due to the presence of a gap between the seal, the sealing and restrictive surfaces of the flanges. In this case, insufficient elasticity of the power system of the connection and resistance to deformation of the seal on the restrictive surfaces of the flanges can lead to a decrease in stresses on the sealing surfaces and the occurrence of a leak in the process of high-temperature thermal cycling.

The utility model [A.E. Vyazovetskova, V.V. Vyazovetskov, Patent for utility model No. 169119, "Ultra-high vacuum sealing joint"]. It has the design of a standard connection [Vacuum equipment. Flange connections for ultrahigh vacuum systems. GOST 26526-85] is supplemented with an elastic power system and a rigid centering ring. The increased extent of the elastic effect of the power system of the tie elements on the plastic sealant increases the reliability of the sealing of the joint, helping to maintain the force interaction of the contacts of the sealing surfaces. The presence of longer and more rigid steel centering surfaces reduces the effect on the sealing surfaces of the connection of external influences applied to the vacuum line, makes it easier to align the vacuum line, and also increases the ease of mounting the connection.

The described compound is operable at room temperature and a low heating temperature (up to 100-150°C). However, carrying out degassing warm-ups at high warm-up temperatures (250°C or more) will lead to leakage after several temperature cycles due to a sharp decrease in the yield strength and creep of the sealant. The sealing surfaces are introduced into the seal with a decrease in contact stresses on them. The displacement of the seal from the highly loaded sealing area is facilitated by the presence of free adjacent surface areas near the loaded sealing surfaces of the seal.

Utility Model Disclosure

The technical problem to be solved by the claimed utility model is to increase the reliability of multiple thermal cycling of the joint by counteracting the creep of the sealant material from the sealing area by increasing the compressive stresses in the deformable part of the sealant located in the vicinity of the sealing area, and maintaining a small stress difference between adjacent areas of the deformable parts of the plastic seal.

The technical result of the claimed utility model is to prevent the displacement of the seal material from the most stressed local sealing surface of the carrier ring by creating a continuous force contact of the seal with the sealing and restrictive surfaces.

The technical result of the claimed utility model is achieved by the fact that an ultra-high-vacuum heated connection is proposed, containing bearing ring elements with local sealing and restrictive surfaces, a deformable sealant installed with force contact with local sealing and restrictive surfaces, an elastic loading system for a deformable sealant, while the deformable sealant is located with continuous force contact with local sealing surfaces and restrictive surfaces of bearing ring elements.

The combination of the above essential features leads to the fact that:

the reliability of maintaining the vacuum density of the ultra-high vacuum connection is significantly increased during repeated high-temperature heating of the connection in comparison with the prototype;

the high filling of the space between the sealing and restrictive surfaces by the stressed sealant, as well as the elastic pressure on the deformable sealant is created in such a way that operational thermomechanical cyclic stresses cannot significantly increase the stress difference on the sealant between the sealing and adjacent sections of the deformable sealant. Such an operating state of the heated ultra-high vacuum detachable joint creates a stagnant zone in the area of the joint sealing against the leakage of the sealant material.

Brief description of the drawings

In FIG. 1 and 2 show sections of a detachable connection, where the numbers indicate:

1 - power ring;

2 - sealing protrusion;

3 - sealing surface of the protrusion 2;

4 - guide surface;

5 - mounting surface

6 - reciprocal power ring

7 - sealing protrusion of the reciprocal power ring

8 - sealing surface of the reciprocal power ring

9 - centering surface

10 - Rigid centering ring

11 - guide surface of the rigid centering ring 10

12 - centering surface of the rigid centering ring 10

13 - mounting surface of the rigid centering ring 10

14 - seal

15 - elastic power ring

16 - tie elements in the form of studs

17 - coupling elements in the form of washers

18 - coupling elements in the form of nuts

In FIG. 3 shows the dependence of the leakage flow Q on the value of the applied sealing force F with the output of the graph of the dependence on the operating point G of the plateau of the CGH curve

Implementation and implementation examples

Below is an example of a specific implementation of the device, which does not limit the options for its implementation.

An increase in stress on the restrictive surfaces of the seal located next to the sealing surfaces is achieved by repeatedly deforming the seal after a certain period of time sufficient for stress relaxation in the seal. In contrast to the method [7], in this case, the seal is molded at its workplace, it is possible to tighten the joint after preheating. The repeated tightening is due to the use of a power system with a reduced sealing force, designed only for the introduction of sealing protrusions into the seal [1].

Installing a rigid centering ring around the periphery of the seal, similarly to the prototype, reduces the volume of the deformable part of the seal and peripheral gaps.

The essence of the design of the proposed useful model of a detachable connection in working condition is illustrated by figures 1, 2, 3. The ultra-high vacuum heated connection contains a power ring 1, on which there is a sealing protrusion 2 with a sealing surface 3, a guide surface 4 and an installation surface 5. On the reciprocal power ring 6 there is a sealing protrusion 7 with a sealing surface 8, a centering surface 9. A rigid centering ring 10 has a guide surface 11, a centering surface 12 and an installation surface 13. The seal 14 is installed on the centering surface 12 of the rigid ring 10 between the sealing surfaces 3 and 8. Elastic power ring 15 is installed on the flange - the reciprocal power ring 6. Coupling elements in the form of studs 16, washers 17 and nuts 18 are fixed on the elastic ring 15 and power ring 1, and some of the studs are threaded evenly along the diameter of the holes connected to the corresponding threaded holes mi hard ring 10.

The figure 1 shows a section of a detachable connection passing through the pin 16. It is freely inserted into the hole of the power ring 1, into the threaded hole of the rigid centering ring 10 and the hole of the power ring 6. The diameter of the hole in the power ring 6 exceeds the diameter of the threaded hole in the rigid centering ring 10 This embodiment is designed to install a forcing bolt into the threaded hole of the rigid power ring 10 after removing the pin during the disassembly of the connection.

At all stages of deformation of the seal, elastic deformation of one or more rings 15 is always carried out, maintaining the force contact interaction of the sealing surfaces 3 and 7 with the seal 14. The value of the residual plastic deformation of the ring 15 should be insignificant. The number and thickness of the rings 15 depends on the geometry of the flanges, the deformation sealing scheme of the joint, and the material of the seal.

To open the heated detachable connections, forcing bolts are used, which are installed in the holes for the studs. For M 8 studs in power ring 6, M 10 threads are cut in holes with a diameter of 8.4 mm. The number of threaded holes is a multiple of four. They are evenly distributed between all the threaded holes for the studs in the rigid centering ring 10. Since such an implementation is possible with a different number of holes, it is therefore not shown in FIG. one.

The main structural material of the joint is steel 12X18H10T (GOST 5632-72). For high temperature warm-ups, nuts and studs should be provided with a coating that prevents the threaded surfaces from seizing (eg sulphurized). Depending on the temperature conditions of operation, the material of the seal can be aluminum or copper alloys.

To exclude the transfer of possible force effects from the vacuum line to the deformation zone of the seal, an elastic connection of one of the flanges with the vacuum line should be provided.

The process of preparing an ultra-high vacuum heated detachable joint for thermal cycling is carried out in 3 stages:

- pre-assembly;

- the stage of setting up the connection for the initial sealing;

- transfer of the connection to the working state for operation in the conditions of thermal cycling of the vacuum system.

The description of the stages of preparing the connection for work is illustrated by figures 1-3.

At the stage of pre-assembly of the connection, the studs of the tie elements 16 are installed in the evenly spaced threaded holes of the centering ring 10, and the sealant 14 is inserted on the guide surface 12 of the centering ring 10. Then the centering ring 10 is brought into contact with the guide surface 4 of the power ring 1 by the guide surface 11. Further the movement of the rigid ring 10 along the guide surface 4 of the force ring 1 leads to the interaction of the mounting surfaces 5 and 13 (see Fig. 2) and the translation of the rigid ring 10 into a position with an emphasis on the force ring 1. In this state, the rigid ring 10 and the force ring 1 are fixed by screwing nuts 18 on the left ends of the studs 16, pre-installed in the rigid ring 10. After that, the force ring 6 with the elastic force ring 15 is moved to the rigid ring 10 with the seal 14, followed by their alignment along the centering surfaces 9 and 12 until contact with the seal 14 sealing ledges 2 and 7. Holding in this state the power rings 1, 6 and the elastic power ring 15 by their outer surfaces, the remaining studs 16 are inserted, washers 17 and nuts 18 are installed on them. termination of the free displacement of all elements of the connection.

The stage of setting up the initial sealing of the connection is carried out by tightening the power rings 1 and 6 by uniformly tightening all nuts 18 with a manometric wrench with a given initial torque. In this case, the sealing surfaces 3 and 8 of the seal 14 are compressed with the obligatory achievement of the vacuum tightness of the joint corresponding to this design. In this case, the seal 14 performs force interaction with the restrictive surfaces formed by the centering surface 12 of the rigid ring 10 and sections of the sealing surfaces 3 and 8 located relative to the sealing protrusions in the peripheral areas. After a certain period of time (depending on the type of the deformation scheme and the material of the seal), the creep of the seal 14 leads to some increase in the area of its contact with the restrictive surfaces and a decrease in the tightening torque of the elements 16-18. The subsequent compression of the power rings 1 and 6 by all the tightening elements 16-18 with a given allowable torque value of the torque wrench leads to the sealing of the connection.

The achievement of the vacuum tightness of the connection is controlled by certified and proven leak detection means and fixes the end of the second stage - primary sealing. Transferring the connection to this stage allows you to maintain the vacuum tightness of the connection in the case of operating the vacuum system at room temperature. The area of the local area of contact between the sealing surfaces 3 and 8 and the seal 14 does not increase significantly in the future after the joint is sealed.

In the absence of the usually achievable degree of tightness (permissible leakage flow through this connection), the connection is disassembled and the reasons preventing the achievement of vacuum tightness and the elimination of assembly defects (presence of dust, scratches on the sealing surfaces) are clarified.

The third stage of the process of sealing the ultra-high-vacuum heated joint is necessarily carried out before its first thermal cycling. To do this, additional tightening of fasteners 16-18 is carried out with a manometric wrench with an acceptable torque value. For flanges with a relatively low sealing force, the connection will be put into working condition by a repeated number of tightening of the fasteners. The amount of weakening of the tightening torque after a certain period of time is an indicator of the filling of the space between the sealing surfaces 3 and 8 and the restrictive surface in the form of a centering surface 12 of a rigid centering ring 10 with a stressed seal 14.

Absolutely complete filling of the gaps is not mandatory, it is important to bring the connection into the operating state of thermal cycling with the formation of a stagnant zone in the sealing area near the sealing protrusions 2 and 7. For this, the stress state of the seal 14 and the force of the elastic power system for compressing the elements 16-18 must be such that that some possible weakening of the applied sealing force, occurring due to the relaxation of high stresses, did not lead to a noticeable decrease in the stress difference between the local sealing area (near the sealing protrusions 2 and 7) and nearby restrictive surfaces (centering surface 12 of the rigid ring 10 and peripheral areas of the sealing surfaces 3 and 8).

The filling of the space between the sealing and restrictive surfaces of the flanges by the sealant, the number and dimensions of the fasteners, as well as the tightening torque of the fasteners in the working state of the joint are selected in such a way that the stressed state of the seal does not allow thermomechanical loads to change the conditions of the stressed interaction of the sealing surfaces sufficient to maintain vacuum tightness connections.

The exit to the working state of the connection can occur in a different number of tightening fasteners, depending on the deformation scheme, the material of the seal, the applied forces. It is possible to tighten fasteners 18-18 after warming up. It is important to transfer the deformable seal to a state of stagnation in the sealing area, in which some change in stresses in any adjacent areas of the seal during force contact of the entire deformable part of the seal with sealing and restrictive surfaces is not significant.

Figure 3 qualitatively shows the dependence of the leakage flow Q on the value of the applied sealing force F with the output of the graph of the dependence on the operating point G of the CGH plateau of the curve (the slope of the graph is close to zero). Curve ABCGH - the direction of the curve of the graph when sealing the connection, curve HGCDE - the direction of the curve of the graph with a decrease in the applied forces to the detachable connection. Q _min - the smallest value of the leakage flow passing through the connection. Zone I - the area of active filling of the gas-conducting channels between the sealing surfaces 3, 8 and the seal 14 at the 1st and 2nd stages of the connection assembly. Zone II corresponds to 2 stages of assembly of the connection with the continuation of the near-surface deformation of the seal, accompanied by an increase in the vacuum density of the connection, and the volumetric filling of the seal 14 with the entire installation space between the sealing 3.8 and the restrictive surface 12. In zone III, the deformation of the seal 14 is reduced to creating a more uniform distribution of stresses next to the sealing lugs 2.7. Characteristic is the inability to further effectively overlap the gas-conducting channels (grooves of roughness of the solid sealing surface) and the presence of the working area of the applied forces CGH, in which some change (increase or decrease) in the applied forces does not lead to a significant change in the leakage flow Q _min .

Disassembly of the connection is carried out in the reverse order of Fig. 12.

First, the compression force of the power rings 1 and 6 is weakened by unscrewing all the nuts 18 of the power system from the side of the power ring 6 and the free studs 16, not fixed in the rigid centering ring 10, are removed. After that, the elastic power ring 15 is removed and the studs installed in the through threaded holes are unscrewed rigid centering ring 10. In this case, the seal 14 after warming up usually remains in contact with the sealing surfaces 3, 8 due to the action of molecular forces. Further, through the passage holes in the power ring 6, the forcing bolts are screwed into the threaded holes of the rigid centering ring 10. By slowly gradually screwing in all the forcing bolts, the rigid centering ring 10 is pressed out from the power ring 1 with the separation of the seal 14 from the sealing surface 3 or the sealing surface 8. In this case, the atmosphere can be admitted into the vacuum system. Then the movement of the rigid ring 6 relative to the power ring 1 is carried out along their mounting surfaces 5 and 13, and then along the guide surfaces 4 and 11.

In the process of pressing the rigid centering ring 10 from the force ring 1, the force ring 6 remains in contact with its guide surface 9 with the guide surface 12 of the centering ring 10. After that, all the forcing bolts are removed from the rigid centering ring 10. Next, the force ring 6 is moved in the axial direction to the right with the withdrawal of its guide surface 9 from the guide surface 12 of the ring 10. Then the force ring 6 with a part of the vacuum line is removed from the force ring 1 to the side, completely opening the vacuum line. Next, the rigid centering ring 10 moves to the right with the studs installed on it, followed by removal from the power ring 1. The seal 14 is carefully removed from the power ring 1 or power ring 6, using the gaps between them. Sealing surfaces are inspected and possible foreign particles (particles of copper oxide, dust) are removed. The disassembly of the connection ends with the blocking of the inlets of the power rings 1 and 6 immediately after opening the connection with plugs or clean calico in order to prevent dust from entering the vacuum system in compliance with the rules of vacuum hygiene.

In the process of cyclic heating of large joints, a decrease in the yield strength of the material of the seal 14 and radial loosening stresses between the seal 14 and the sealing surfaces 3, 7 occur. seal 14, sufficient to prevent the movement of the seal material near the sealing protrusions 2 and 7.

The technical and economic efficiency of the proposed design solutions for the ultra-high vacuum heated connection in comparison with the devices used is to reduce the material and time costs that occur when leakage occurs during thermal cycling of the ultra-high vacuum system. The advantage of the proposed utility model is to increase the reliability of sealing the connection with the implementation of a greater amount of its thermal cycling due to the creation of a stagnant area in the area of sealing. Important is the greater convenience and reliability of the centering of the connection flanges in comparison with the standard device.

Sources of information:

1. Vacuum equipment. Flange connections for ultrahigh vacuum systems. GOST 26526-85.

2. V.V. Anashin, A.A. Krasnov, A.M. Semenov, S.R. Sharafeev "Vacuum-tight connections for obtaining ultrahigh vacuum in vacuum systems of accelerators with wide-aperture chambers", PTE. 2019 No. 5, 134-135.

3. L.A. Filatovsky, A.S. Shuvalov, O.K. Kurbatov, S.D. Vasilchenko "New small-sized ultra-high-vacuum flange connections", Electronic engineering, Series TOPO, 1982, no. 3 (112), p. 62-64.

4. A.S. Shuvalov "Connecting elements of ultra-high vacuum systems". Vacuum technique and technology, 1994, vol. 4, no. 4, p. 2-25

5. O.K. Kurbatov "Physico-technical foundations of optimized high-vacuum magnetic discharge pumps, sealing elements and devices for vacuum technological and analytical equipment of electronic technology", Abstract of the dissertation for the degree of Doctor of Technical Sciences, Moscow, 2006.

6. "Handbook of vacuum technology and technology", ed. D. Hoffman, B. Singh, J. Thomas III. Translation from English, edited by V.A. Romanko, S.B. Nesterov. M. "TECHNOSPHERE", 2011, -736 p.

7. V.G. Danchenko, F.P. Savin, V.I. Kosinsky Author's certificate of the USSR SU 1043411 A. F16L 19/00, F16L 23/00. "Method of sealing detachable connection of cryogenic pipelines". Published 03/23/83 Bull. No. 35.

8. Rene Bernard, USSR Patent No. 291493, F 16 j 15/08, "Gasket for sealing fixed joints." Published January 6, 1971 Bulletin No. 3.

9. D.B. Zworykin "Issues of calculation and design of all-metal high-vacuum systems and their elements". Dissertation for the degree of candidate of technical sciences. NII MRTP, 1955.

10. A.V. Nesterov. USSR Invention No. 1760227, F16L 23/16, "Ultra-high vacuum connection", Publ. 07.09.92 Bull. No. 33.

11. A.S. Shuvalov, A.T. Alexandrova, I.F. Lobanov, B.G. Lvov, V.F. Zakrevsky, USSR Author's certificate SU No. 1180634 A, F16L 23/02, "Ultra-high vacuum detachable connection". Published 09/23/85 Bull. No. 35.

12. A.E. Vyazovetskova, V.V. Vyazovetskov, Utility model patent No. 169119, F16L 23/02, "Ultra-high vacuum sealing joint". Published 03/03/2017.

Claims (1)

Ultra-high-vacuum heated connection containing bearing ring elements with local sealing and restrictive surfaces, a deformable seal installed with the possibility of force contact with local sealing and restrictive surfaces, an elastic loading system of a deformable seal, characterized in that the deformable seal is located in continuous force contact with local sealing surfaces and restrictive surfaces of the bearing ring elements.

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