CN1306197C - Vacuum valve without rubbish pollution - Google Patents

Abstract

The present invention belongs to the manufacture field of high-temperature alloy powder equipment production. The present invention relates to a powder transmission vacuum valve without rubbish pollution, which is especially suitable to be used in vacuum equipment systems. The vacuum valve without rubbish pollution is characterized in that each valve cover is provided with fastening screws; each valve cover is sealed with a transitional ring and an outer valve body; a stainless steel wire soft-net cylinder is arranged between the transitional rings on both ends of the outer valve body, a sealing ring and a powder transmission passage with a wedged surface are arranged on the contact surface of each transitional ring and the outer valve body, the upper end opening and the lower end opening of the stainless steel wire soft-net cylinder are tightly pressed, and the middle of one side of the stainless steel wire soft-net cylinder of the funnel-shaped powder transfusion passage is installed on a sliding block installed on the front end of a screw; an inner valve body is a cylinder with a thick cylinder wall, the middle on both symmetrical sides in the inner valve body is provided with a hole in which a pushing block is installed, and the front end of the hole is provided with a sliding block screw; both sides of the pushing block are provided with convex bar-shaped slide rails. The stainless steel wire soft-net cylinder is a cylinder formed by rolling 2 to 3 layers of stainless steel wire soft-nets with the hole diameters of 30 to 50 mu m. Compared with the prior art, the vacuum valve of the present invention has the characteristics of simple and reasonable structure design, easy and convenient preparation, easy and convenient operation, long service life of the valve, etc.; the present invention can effectively control organic rubbish pollution in powder.

Description

A kind of vacuum valve without rubbish pollution

Technical field

The invention belongs to the manufacturing field that produces superalloy powder equipment.Particularly suitable in the vacuum equipment system must use the vacuum valve of defeated powder with no rubbish pollution.

Background technique

Refractory alloy is industrial field key in application materials under high temperature complex load and hot environment such as Aeronautics and Astronautics, petrochemical industry.And the powder metallurgy superalloy material is to be mainly used in the refractory alloy that property requires, and this alloy material end has that crystal grain is tiny, even tissue, stretch-proof and anti-fatigue performance are good, is the preferred material that the aeroengine critical component is made.The preparation of superalloy powder is the basis of the powder metallurgy superalloy manufacturing and important link.Having an important problem in the manufacturing of superalloy powder, is exactly sonims.Because the existence of sonims will directly reduce the performance of alloy material, particularly reduce the low-cycle fatigue life of alloy material, having a strong impact on the working life of product, as the airborne period and the Security of aircraft motor.Mainly be divided into organic being mingled with and inorganic two classes that are mingled with for the sonims in the material, wherein inorganic being mingled with is to be left over by refractory material in the smelting process and slag etc. to form, organic being mingled with then is that extraneous contamination by in powder process, defeated powder and the storage powder system is formed, and wherein employed existing sphere or the plate valve door that has the organic substance part device is exactly main organic rubbish pollution source in the vacuum system of pulverizing process.In present superalloy powder production preparation process, the normal valve that uses has two kinds in the vacuum system of powder process and defeated powder, a kind of is spherical valve, as shown in Figure 6, in a cylinder valve that has a upper and lower covers, the Stainless Steel Ball that has through hole as a centre of critical piece, this valve ball is to link to each other with external handle, can rotate, lower peripheral surface contacts with pulverized coal feed pipe on it, and the end that contacts with sphere of pulverized coal feed pipe respectively is inlaid with a poly-tetrafluoro packing ring up and down, mainly is to be in contact with it face seal for valve ball with holes when rotating, during work, when the intermediate hole of valve ball forwards to when pulverized coal feed pipe is at same axis up and down, powder will be with the pulverized coal feed pipe of peak rate of flow by valve body, along with handle rotates, the intermediate hole axis of valve sphere gradually with the pulverized coal feed pipe axis runout, powder mass flow reduces gradually until closing at last.In valve ball rotation process with holes, intermediate hole knife-edge can contact cutting with the poly-tetrafluoro packing ring that seals, so that produce organic debris, form organic slag inclusion, simultaneously because the powder of flowing through is hard tiny, when rotating, steel ball is trapped in easily between valve ball face and the poly-tetrafluoro packing ring, poly-tetrafluoro packing ring is produced grinding, thereby cause the chip of poly-tetrafluoro to come off, even the rubbing action that embeds owing to powder causes valve ball to rotate difficulty or blow-by, cause valve body normally not use, reduce working life.And for another kind plate valve commonly used; its principle as shown in Figure 7; the work signal of this plate valve is to have the structural member of a disc to link to each other with a Joystick in an oblate column valve body; when duff pipe is middle about disk is positioned at; then powder is blocked; do not circulate; and when driving handle makes the disk turn-off; then the powder road is communicated with up and down; powder flows through, and what of powder mass flow are the distance that departs from disk axis and defeated powder passage axis control, in order to seal; on disk, be inlaid with the vacuum rubber circle; when the disk rotary seal is failed the powder passage up and down, rubber ring and the contact friction of duff pipe end, thus cause rubber scraps to come off; form organic being mingled with; powder particle does not directly wash away cushion rubber during owing to work, so the working life of plate valve is more longer than ball valve but by contrast; but have equally the powder of residue adhesion on the disk rubber ring can with the contact friction of duff pipe end, cause the rotation difficulty and the gas leakage of valve.Show that after deliberation 80% organic being mingled with all may be from the pollution of valve in the powder.In addition, because hard powder particle contact friction with softer organic component, after use a period of time, the organic substance component wear causes valve can not use shortening in working life with manufacturing mechanism.

Goal of the invention and content

The objective of the invention is to propose a kind of structural design simply, rationally, preparation is easy, convenient with use, and can control the vacuum valve without rubbish pollution that the organic slag inclusion in the product powder pollutes effectively.

According to purpose of the present invention, the design route that we proposed is not use organic substance (as poly-tetrafluoro in the defeated powder access site of valve, vacuum is as glue etc.) as the control flow of powder, realize the parts of valve opening and closing, thereby do not produce organic rubbish pollution, and obtain a kind of organic vacuum valve that is mingled with existence of eliminating effectively or control, in the solution of the technology of the present invention, also propose in addition a kind of adopt anti-hard metal powder particle erosive wear, have a vacuum valve silk screen than the long life.In order to solve the problems of the technologies described above and realize to use for a long time and eliminate the purpose that organic slag inclusion pollutes, the overall structure of our the designed and vacuum valve without rubbish pollution that proposes is by on valve housing and the valve, lower cover, the middle transition ring, in, outer valve, the stainless (steel) wire tube, boss on the inner valve body and the slider part composition that joins, valve housing loam cake 1 and lower cover 13 in circle have into powder and powder delivery tubular shape passage, and each interface again respectively with the corresponding connection mutually of the vacuum system of powder process (or powder processing), it is characterized in that four clamping bolts and transition ring 2 are arranged respectively on each valve gap, 11 and outer valve 3 be the sealing join, the diameter dimension of outer valve 3 loam cakes 1 is less than the diameter dimension of lower cover 13, the soft net tube 7 of Stainless Steel Wire is installed between transition ring 2 on outer valve 3 two ends and following transition ring 11, on transition ring and outer valve 3 surface of contact, be provided with seal ring 17 and the defeated powder passage 18 that has wedge shape (taper) face, and with on the soft net tube 7 of Stainless Steel Wire installed, lower end mouth compresses, this outer valve 3 is a cylindrical shape, by last, following four clamping bolts partly are with loam cake 1, lower cover 13 and last transition ring 2, following 11 fastening joining of transition ring, be contained on the slide block 6 that the front end of screw rod 8 installs in the soft net tube of the Stainless Steel Wire 7 one side intermediate portions of the defeated powder passage of funnel shape, and by the soft net tube 7 of screw in compression Stainless Steel Wire, inner valve body 14 is a cylindrical shape that barrel is thicker, the bottom is for having the end cap of convex edge, four positions and size and last are set above, the bolt hole 16 that lower cover and outer valve bottom are identical, intermediate portion in inner valve body Cylindorical rod symmetry both sides has hole, and the control screw rod 8 that jacking block 4 and front end are equipped with slide block 6 is housed, jacking block 4 is cylindrical mosaic blocks of a hollow, be embedded on the inner valve body 14, a circular pressure pad 5 is equipped with on its top, and slide block 6 and screw rod 8 constitute to be opened, the drive mechanism of closing valve.It is that both sides have protruding bar shaped slide rail that other features in vacuum valve without rubbish pollution of the present invention also have slide block 6, an end sealing-in screw rod 8 front ends, the other end is open cylindrical shell shape, its inner hollow and have in the system screw thread.It is to be that the Stainless Steel Wire soft net volume of 30-50 μ m becomes cylindric shape by an aperture size that other features also have the soft net tube 7 of the defeated powder passage Stainless Steel Wire in this valve, and the overlapping number of plies of the soft net of the Stainless Steel Wire after being rolled into is a layer 2-3.Be wedge shape (taper) structure in the inner outside of the defeated powder passage of upper and lower transition ring, it mainly acts on is the two-port that can effectively compress the soft net of Stainless Steel Wire when this valve body of assembling.

For vacuum valve without rubbish pollution content of the present invention and principle are further described, we can be described in detail with reference to the accompanying drawings, and in accompanying drawing of the present invention: accompanying drawing 1 is the generalized section vertically of vacuum valve without rubbish pollution of the present invention; Accompanying drawing 2 is end view of valve body inner slide; Accompanying drawing 3 is looked schematic representation for the section of valve body inner slide; Accompanying drawing 4 is the schematic representation of valve body inner screw; Accompanying drawing 5 is the coiling schematic representation that stainless steel silk car produces the net tube in the valve body; Accompanying drawing 6 is system in the prior art, defeated powder vacuum ball valve; Accompanying drawing 7 is system in the prior art, defeated powder evacuated panel shape valve.Can find out that with reference to the accompanying drawings valve housing loam cake 1 and lower cover 13 circular in accompanying drawing 1 have into powder and powder delivery tubular shape passage, and respectively have interface to be connected with the vacuum system of powder process (or powder processing).Each cover have respectively four fastening screws link to each other with outer valve 3 with transition ring 2,11, fastening.Because the upper and lower diameter dimension difference of outer valve 3, so the diameter dimension of loam cake 1, lower cover 13 has any different, and lower cover 13 external diameters are big slightly.Transition ring is respectively transition ring 2 and following transition ring 11, on transition ring and outer valve 3 surface of contact, designed the defeated powder passage 18 that has wedge shape (taper) face, it mainly acts on is in order to install, compress the upper and lower port of the soft net tube 7 of stainless steel silk, this net tube 7 is had a fixation, have on the transition ring simultaneously seal ring 17 with guarantee and loam cake 1, lower cover 13 between sealing.Outer valve 3 is cylindrical shells, the end cap that has on top has determined the size of the main profile (diametric(al)) of valve, critical piece as valve, its each four bolt silk and loam cake 1, lower cover 13 and last transition ring 2, following transition ring 11 by upper and lower part links, on top funnel shaped defeated powder passage 19 is arranged so that be complementary with the wedge shape duff pipe of transition ring, one side intermediate portion is installed the boss 10 that having middle screw of screw rod in addition simultaneously, in order to link to each other with inner valve body 14, the base diameter size of outer valve 3 is big slightly, has a convex edge.The upper end cap of outer valve 3 has seal ring 17 so that play seal action when being connected with last transition ring 2.Inner valve body 14 also be one columnar structured, barrel is thicker, the bottom has end cap, and the convex edge is arranged, four positions screw 16 identical with upper and lower cover and outer valve bottom with size is set above so that be connected and fixed with outer valve 3 etc., intermediate portion in inner valve body Cylindorical rod symmetry both sides has hole, so that jacking block 4 and control screw rod 8 and slide block 6 are installed.Its bottom also is equipped with and is played seal action when seal ring 17 is connected with middle transition ring 11.Knuckle place, convex edge seal ring 12 is in order to seal with outer valve, jacking block 4 is cylindrical mosaic blocks of a hollow, be embedded on the inner valve body 14, circular cushion 5 of its top bonding, side top when jacking block is netted tube 7 closures as the stainless steel silk is soft, inlay motionlessly on the inner body, cushion 5 mainly is the effects playing buffering and prevent soft net tube 7 wearing and tearing of stainless steel silk.Slide block 6 and screw rod 8 have constituted the main drive mechanism of valve, as accompanying drawing 2, shown in the accompanying drawing 3, slide block 6 is bar shaped slide rails 21 that both sides have projection, the sealing of one end, one end is free and open, inner hollow, the cylindrical shell that has internal thread 32, the bar shaped slide rail gets on the right track with inner valve body and matches, be in order to guarantee that slide block is when screw rod 8 moves, can only slide forward or backward, and do not rotate, there is the groove 33 of a band screw in the sealed end center portion, can couple together with a sidewall intermediate portion and the slide block 6 of round head bolt, and screw rod 8 and slide block 6 inwalls are by being threaded, during the rotating screw bolt handle the soft net tube 7 of stainless steel silk, promote slide block 6 and move forward and backward, thereby realize opening of valve, cooperation is used.Design has boss on the screw rod 8, and as shown in Figure 4,41 1 effects of boss are that lock nut 8 prevents to move, and places seal ring 44 on the other hand on it, further plays seal action.Rotatable handles 43 when the flow of control powder when realizing left-handed moving screw rod 8, promotes slide block 6, closed stainless steel wire mesh tube 7, during dextrorotation, pulling slide block 6, the soft net tube 7 of stainless steel silk opens, and controls the flow of powder by the soft net tube 7 open distance sizes of stainless steel silk.The soft net tube 7 of stainless steel silk is that the Stainless Steel Cloth by a 30-50 μ m mesh is rolled into tubular, specifically as shown in Figure 5, play initial line 51 and last side 52, necessary some cross-coincidence, wall thickness is the overlapping number of plies of the Stainless Steel Cloth of layer 2-3, the intermediate portion of the district of crimping coincidence in the end place sidewall is passed sidewall with countersunk head screw 53 and is linked to each other with slide block 6 tops, so that pulling stainless steel soft net tube 7 pulverized coal feed pipes of silk opened when slide block 6 slided, close, during installation, on the net tube, the underpart is closely contacted with the funnel shape duff pipe 19 of outer valve by the defeated powder passage exterior edge face 18 of the wedge shape of transition ring, pressing, thereby the soft net tube 7 of stainless steel silk is played fixation, but the key technology point that an operation is arranged when installing: on should after control screw rod 8 promotes slide blocks 6 closed net tubes, will net with transition ring again tin, lower end and outer valve compress, so that stay enough movable distance for the folding of the soft net tube 7 of stainless steel silk.The nut of installing in outer valve boss 11 ends 9; Play the effect of support fixation control screw rod 8 on the other hand, further seal by 15 pairs of valve bodies of seal ring on the one hand.

Adopt vacuum valve without rubbish pollution of the present invention to have structural design compared with prior art simply, rationally, preparation is easy, convenient with use, and can control the characteristics such as organic slag inclusion pollution in the powder-product effectively.Also having pulverized coal feed pipe in the valve body in the present invention in addition is to adopt fine and closely woven, a pliable and tough resilient Stainless Steel Cloth of mesh to be rolled into tubular and form, because the Stainless Steel Cloth tube is continuously whole, powder only contacts with this net tube inwall, does not produce friction with other any organic substance parts.Require: the wall thickness layer 2-3 net of (1) volume back Stainless Steel Cloth tube, because the juxtaposition of mesh, therefore at present the powder of the conventional 40-500 μ m particle size of using can not leak into outside the net tube, even micro-seepage is arranged, the proper functioning of valve is not exerted an influence yet.Be no more than 3 layers of net simultaneously owing to the Stainless Steel Cloth barrel is thick, therefore still keep its pliability and elasticity, if powder particle is trapped on barrel when the Stainless Steel Cloth tube is closed simultaneously, then be partly embedded in the mesh owing to it, barrel and this net tube only produced squeezing action when the Stainless Steel Cloth tube was closed, do not produce friction, nor it is tight to cause the Stainless Steel Cloth tube to close, so working life is very long; (2) diameter dimension behind the Stainless Steel Cloth tube volume requires between 18-22mm, and diameter is excessive, and envelope is not tight when then closed, and diameter is too small, causes the flow of powder too small on the one hand, reduces working efficiency, is unfavorable on the other hand installing.Need to prove, select the Stainless Steel Cloth of 30-50 μ m mesh to make this net tube, mainly based on following 3 reasons: (1) our employed particle size is about 40-500 μ m interval, if, then need select for use the Stainless Steel Cloth of 30 μ m meshes to make the Stainless Steel Cloth tube for the powder (20-600 μ m) of thin size; The Stainless Steel Cloth of the following mesh of (2) 50 μ m has good pliability and elasticity; (3) the anti-alloy powder particle of Stainless Steel Cloth wash away with abrasiveness good.The another one characteristics are that the vacuum seal of valve body does not realize by the pulverized coal feed pipe in the control valve, blocking effect when the Stainless Steel Cloth tube is closed just flows at metallic dust, do not play sealed valve body, the sealing of valve body then adds that vacuum seal is covered and realizes by the seal ring of region of interest on the valve and in (going out) the tube cell end of advancing that loam cake (or lower cover) links to each other with vacuum system.Be that at last main valve body except that upper and lower cover is not an integral body in the vacuum valve without rubbish pollution of the present invention, but form, so that realize the designing requirement of net tube folding by outer valve and inner valve body suit.Therefore adopt vacuum valve without rubbish pollution of the present invention to compare than the spherical valve or the plate valve of prior art as can be seen, it is obvious to have the rubbish pollution of elimination effect, characteristics such as the long service life of vacuum valve and good reliability.

Description of drawings

Accompanying drawing in specification of the present invention is respectively: accompanying drawing 1 is the generalized section vertically of vacuum valve without rubbish pollution of the present invention; Accompanying drawing 2 is end view of valve body inner slide; Accompanying drawing 3 is looked schematic representation for the section of valve body inner slide; Accompanying drawing 4 is the schematic representation of valve body inner screw; Accompanying drawing 5 is the coiling schematic representation of stainless steel wire mesh tube in the valve body; Accompanying drawing 6 is system in the prior art, defeated powder vacuum ball valve; Accompanying drawing 7 is system in the prior art, defeated powder evacuated panel shape valve.Sequence number in above accompanying drawing is respectively: 1, loam cake; 2, go up transition ring; 3, outer valve; 4, jacking block; 5, cushion; 6, slide block; 7, the soft net tube of Stainless Steel Wire; 8, control screw rod; 9, sealing nut; 10, outer valve boss; 11, following transition ring; 12, seal ring; 13, lower cover; 14, inner valve body; 15, seal ring; 16, bolt hole; 17, seal ring; 18, wedge duff pipe end; 19, funnel shape duff pipe end; 21, bar shaped slide rail; 32 internal threads; 33, screw hole; 41, screw rod boss; 42, screw thread; 43 handles; , 44, the screw rod seal ring; 51, the initial sideline of stainless steel silk screen; 52, the stainless steel silk screen stops the sideline; 53, the sidewall of stainless steel silk screen and slide block tie point; 61, poly-tetrafluoro packing ring; 62, go up duff pipe; 63, steel ball valve; 64, handle; 65, valve mesopore; 66, following duff pipe; 71, disk; 72, rubber ring; 73, upward defeated powder passage; 74, following defeated powder passage; 75, handle.

Specific embodiments

Powder adopts nickel base superalloy powder (chemical composition: wt%, C:0.065%, Cr:12.87%, Co:7.54%, (Al+Ti): 6.00%, Ni is surplus), the granularity of powder is divided into two kinds: powder degree before the screening: 40-500 μ m, screening back powder degree: 50-150 μ m.In the vacuum system of powder process and powder-processed, adopt ball valve, plate valve and no organic valve (having the soft net tube of 50 μ m mesh diameters and the soft net tube of 30 μ m mesh diameters) that is mingled with to compare research, the project of test comprises that working life and organic substance are mingled with quantity, wherein working life with total accumulative total to the valve of flow (20Kg/h) of per hour handling 20 kilograms of powder damage service time (hour, h) calculate, and organic The amount of inclusions uses behind the certain hour with continuous that organic quantity that is mingled with is standard in the detected per kilogram powder.

1, the test in working life.The concrete condition of contrast test is as shown in table 1, logical state test result and show, use traditional ball valve, handle screening back powder and (be about the 700Kg powder) in the time of nearly 35 hours, valve rotates difficulty, can't proper functioning, and use no organic valve that is mingled with of the present invention, when the processing powder reaches 150 hours (being about the 3000Kg powder), still working properly, the damage sign is not arranged.Also show simultaneously, when handled particle size is 40-500 μ m, adopt the soft net tube of 50 μ m mesh diameters and soft no organic valve effect that is mingled with of netting tube of 30 μ m mesh diameters not to have difference.Though in addition the working life of plate valve longer than ball valve, therefore the cost price of plate valve is higher more than 3 times than ball valve, takes all factors into consideration not have competitive ability.

The comparing result table in working life of table 1 embodiment of the invention and prior art valve

Numbering	Title	Valve working life, hour h		Remarks
					Powder before the screening	Screening back powder
		1	Ball valve				25.5	34.5	Damage
2	Plate valve			47.5	60	Damage
		3	Do not have and be mingled with valve (50 μ m net tube)				120	150	Do not damage still and using
4	Do not have and be mingled with valve (30 μ m net tube)			120	150	Do not damage still and using

2, the contrast of testing about organic The amount of inclusions in the embodiment of the invention and the prior art.The test comparison situation is shown in Table 2, and shows by test result, no matter after adopting the metallic dust of which kind of granularity and continuously using the long period, vacuum valve of the present invention all not have to produce because of the wearing and tearing of equipment unit etc. increasing of organic slag inclusion.

Table 2 is compared with the prior art the detection of organic The amount of inclusions for the embodiment of the invention

Numbering	Title	Organic The amount of inclusions, individual/Kg						Remarks
									Powder before the screening			Screening back powder
		5h	10h	20h	5h	10h	20h
									1	Ball valve	7	15	24	5		12	22	Exceed standard
2	Plate valve	5	13	22	4	12	18	Exceed standard
									3	Do not have and be mingled with valve (50 μ m net tube)	0	1	1	0	0	0
4	Do not have and be mingled with valve (30 μ m net tube)	0	0	0	0	0	0

Claims (4)

1, a kind of vacuum valve without rubbish pollution, the overall structure of this vacuum valve is by on valve housing and the valve, lower cover, on, following transition ring, in, outer valve, the soft net tube of Stainless Steel Wire, boss structure on the inner valve body and the slider part composition that joins, circular valve housing loam cake (1) and lower cover (13) have into powder and powder delivery tubular shape passage, and interface and the mutual corresponding connection of the vacuum system of powder process are arranged respectively, it is characterized in that four clamping bolts and last are arranged respectively on each valve gap, following transition ring (2,11) and outer valve (3) be the sealing join, the diameter dimension of the loam cake (1) of outer valve (3) is less than the diameter dimension of lower cover (13), the soft net tube of Stainless Steel Wire (7) is installed between the last transition ring (2) at outer valve (3) two ends and following transition ring (11), last, following transition ring (2,11) be provided with seal ring (17) with outer valve (3) surface of contact and have the defeated powder passage (18) of sphenoid surface, and with on the soft net tube of Stainless Steel Wire (7) installed, lower end mouth compresses, this outer valve (3) is a cylindrical shape, by last, following four bolts partly are with loam cake (1), lower cover (13) and last transition ring (2), fastening joining of following transition ring (11), be contained on the slide block (6) that the front end of control screw rod (8) installs in the soft net tube of Stainless Steel Wire (7) the one side intermediate portions of the defeated powder passage of funnel shape, and by the soft net tube of screw in compression Stainless Steel Wire (7), inner valve body (14) is a cylindrical shape that barrel is thicker, the bottom is for having the end cap of convex edge, four positions and size and last are set above, the bolt hole (16) that lower cover and outer valve bottom are identical, intermediate portion in inner valve body Cylindorical rod symmetry both sides has hole, and the described control screw rod (8) that jacking block (4) and front end are equipped with slide block (6) is housed, jacking block (4) is the cylindrical mosaic block of a hollow, be embedded on the inner valve body (14), a circular pressure pad (5) is equipped with on its top, and slide block (6) and described control screw rod (8) constitute to be opened, the drive mechanism of closing valve.

2, according to the described vacuum valve without rubbish pollution of claim 1, its feature is that also the slide block (6) in this vacuum valve is that both sides have protruding bar shaped slide rail, one end sealing-in is at the front end of described control screw rod (8), the other end is open cylindrical shell shape, its inner hollow and have in the system screw thread.

3, according to the described vacuum valve without rubbish pollution of claim 1, it is to be that the Stainless Steel Wire soft net volume of 30-50 μ m becomes cylindric shape by an aperture size that its feature also has the soft net tube of the defeated powder passage Stainless Steel Wire in this valve (7), and the overlapping number of plies of the soft net of the Stainless Steel Wire after being rolled into is a layer 2-3.

4,, it is characterized in that the inner outside of the defeated powder passage of upper and lower transition ring in this valve is wedge-shaped structure according to the described vacuum valve without rubbish pollution of claim 1.

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