CN2249339Y

CN2249339Y - Corrugated pipe sealing device for valve

Info

Publication number: CN2249339Y
Application number: CN 95244692
Authority: CN
Inventors: 高伟鸿; 屠光辉; 沈永光
Original assignee: Shanghai Chemical Fiber Textile Tech Co Shanghai
Current assignee: Shanghai Chemical Fiber Textile Tech Co Shanghai
Priority date: 1995-09-11
Filing date: 1995-09-11
Publication date: 1997-03-12
Anticipated expiration: 2005-09-11

Abstract

The utility model relates to a corrugated pipe sealing device for a valve, which comprises an upper valve body and a valve rod. An upper end cover is sheathed on the upper part of the valve rod, and a lower end sleeve is sheathed on the lower part of the valve rod; the upper end cover is fixed on an upper valve body, and the lower end sleeve is welded on the valve rod; two to four corrugated pipes which are in series connection are welded between the upper end cover and the lower end sleeve, and guide sleeves are weld between the two to four corrugated pipes; the upper end cover, the corrugated pipes, the guide sleeves, and the lower end sleeve are welded into a sealing corrugated pipe assembly with a large offset. The utility model has the advantages of simple manufacturing technique, low cost, reliable sealing performance, and long service life, etc. The valve formed by the utility model is especially suitable for the control of virulent, valued, and easily volatile, and easily osmotic medium.

Description

The valve bellow seal

The utility model relates to the shaft sealer that a kind of valve is used, and specifically, is a kind of valve bellow seal.

In prior art, the shaft sealer that valve is used is divided into two big classes, one class is a packing seal formula structure, and it is to select appropriate filler for use according to the medium kind, operating temperature and the working pressure that circulate in the valve, as materials such as rubber, tetrafluoroethylene, asbestos braided fabrics.Regulate the stuffing box packing that is arranged in around the valve rod pretightening force by adjusting screw (passing through briquetting), reach and make the purpose that medium is isolated from the outside in the valve pipe, play the effect of sealing valve rod.This structure must regularly replace filler owing to the frequent valve rod that moves makes the filler wearing and tearing easily, and life cycle is short.Another kind of is bellows (metal) sealed construction, the bellows upper/lower terminal welds with upper end cap and lower end cap respectively, upper end cap, bellows and lower end cover are formed a bellows component that is enclosed within the valve rod outside, the upper end cap of bellows utilizes seal washer and upper valve body to fix, and the lower end cover of bellows is fixing with the valve rod welding.Because sealing part all adopts the mode of fixing seal, sealing is reliable.The displacement of valve rod makes bellows produce resiliently deformable, utilizes bellows to have the characteristics of resiliently deformable, and the valve medium is isolated from the outside, and does not have the filler wear problems.But there is following defective in the structure of a this bellows: because a lot (D of the large and small specification of bore of control valve _N=20～300mm).The D of different bores _NThe displacement amount of corresponding spool has 10,16,25,40,60 and many grades of requirements such as 100mm, and it is corresponding with the spool travel amount that the elastic deformation amount of bellows requires, so the requirement of the displacement amount of the resiliently deformable of bellows is very big.And the conventional bellows wave number of China's production at present is less, length is short, displacement amount is less.The wave number of the metal bellows of producing as Shanghai elastic element factory is between n=4～16, and the displacement amount of unit ripple can not satisfy the needs of big displacement quantity spool between 0.12～0.8mm.The big displacement quantity bellows technical merit of making the many wave numbers of over-long specification requires height, complex process, cost of production height.In addition, because the wave number of big displacement quantity bellows is many, the ratio of its length L and diameter D is big, easy unstability when displacement, the generation axis is crooked, shown in Fig. 2 (Fig. 2 is a bellows unstability schematic representation) bellows inwall (trough) is directly contacted with valve rod, produces wearing and tearing, cause bellows breakage and dielectric leakage, shorten the working life and the sealing reliability of bellows.

The purpose of this utility model provides a kind of valve bellow seal of being made up of many bellowss, and it is simple that it has manufacturing process, characteristics such as cost of production is low, sealability is reliable, long service life.Effectively prevented the defective of upper and lower easy unstability and valve rod friction when mobile of big displacement quantity bellows.

The utility model is to realize like this, this valve that is used for valve seal is formed with bellow seal and is comprised upper valve body, there is valve rod at the upper valve body center, valve rod top is with upper end cap, upper end cap is the cylindrical ferrule that step is arranged, upper end cap and valve rod are movingly, and upper end cap is fixed on upper valve body by top cover, screw and the soft circle of filling out of upper and lower two sealings.Stem lower portion is with the lower end cover, the lower end is a cylindrical ferrule, welded bellows between upper end cap and the lower end cover, be characterized in that bellows is to be composed in series by 2～4 bellowss, there is guide sleeve to connect between two adjacent bellowss, guide sleeve is middle round-meshed lasso, is welded into a bellows component that is enclosed within the big displacement of valve rod outside between upper end cap, bellows, guide sleeve and the lower end cover, and the lower end cover is welded on the valve rod.Its working principle is: when the flow of valve regulated pipeline internal medium, valve rod produces displacement, the large displacement corrugated pipe that upper end cap, bellows, guide sleeve and lower end cover are welded into produces resiliently deformable, owing to connect guide sleeve between two adjacent bellowss, guide sleeve had both connected upper and lower bellows, relying on valve rod again is guiding, guaranteeing that bellows is upper and lower is difficult for unstability when mobile, effectively prevent a lengthy bellows easy unstability generation axis when displacement in the prior art crooked and with the defective of stem wear.Upper end cap, top cover, screw and two soft circles of filling out of sealing are fixed on upper valve body, guarantee flowing medium and valve body isolation in the valve.

Bellows the best of the present utility model is composed in series by 2 or 3 bellowss, according to different-diameter (the displacement of valve rod amount of 20～300mm) control valve need form best with 2 or 3 bellowss.

Weld by roll welding or argon arc welding between upper end cap of the present utility model, short corrugated pipe, guide sleeve and the lower end cover.Strong, the good airproof performance of fastness with roll welding or the welding of argon arc welding advanced technologies.

Liner stuffing box packing between top cover of the present utility model and the valve rod.The sealing filler is called secondary seal, and the bellows bursts of making provision against emergencies is cushioned by stuffing box packing, makes medium can not leak into the external world at once.

Bellows of the present utility model, guide sleeve, upper end cap and lower end cap are made up of stainless steel material.Have anti-corrosion, compression resistance, advantage such as not easy to wear.

Top cover of the present utility model is other to connect pressure gauge, and manometric joint communicates with the bellows inner chamber.Just in case bellows bursts on the one hand, is cushioned by above-mentioned stuffing box packing, on the other hand, pressure gauge is reported to the police at once, allows operator go if having time to adopt an effective measure, and guarantees the safety of equipment.

With the valve that the utility model is formed, be applicable to severe toxicity, valuable, the volatile and control of easily oozing medium, be specially adapted to not allow under the operating mode of medium external leakage and use.

The utility model compared with the prior art, the following tangible advantage of tool: one, the bellows component that is composed in series by 2～4 bellowss, because the guide sleeve between the adjacent bellows had both played the effect that connects upper and lower bellows, play relying on valve rod to be guiding again, guarantee the upper and lower effect that the crooked phenomenon of axis does not take place when mobile of bellows component.Effectively prevent the trough of bellows and the friction loss between the valve rod, improved the sealing reliability and the working life of product greatly.Two, adopt the bellows of regular size to be combined into the big displacement quantity bellows component, simplified manufacturing process, cost of production reduces.Three, because upper end cap, bellows, guide sleeve and roll welding is applied mechanically in the lower end or argon arc welding is welded into the large displacement corrugated pipe assembly, the welding fastness is strong, and overall tightness is good.Four, the production of bellows commonly used is beneficial to the standardization effort of bellows.Overcome in the prior art and made Sealing with a lengthy bellows, when displacement is big, the crooked defective with the valve rod friction wear of the easy unstability generation of bellows axis.Also overcome lengthy bellows and made processed complex, the higher defective of cost of production.

Now in conjunction with the accompanying drawings an embodiment of the present utility model is specified.

Fig. 1 is a structural drawing of the present utility model.

Number in the figure is represented: 1-valve rod, 2-stuffing box packing, 3-top cover, 4-screw, soft circle, 6-upper end cap, 7-upper valve body, 8-bellows, 9-guide sleeve, 10-lower end cover, the 11-pressure gauge filled out of 5-sealing.

Be a most preferred embodiment of the present utility model (referring to accompanying drawing) below.

A kind of valve bellow seal, form and comprise that there is valve rod [1] at upper valve body [7] center, valve rod [1] top is with upper end cap [6], upper end cap [6] is by top cover [3], on screw [4] reaches, following two soft circles [5] of filling out of sealing are fixed on upper valve body [7], valve rod [1] bottom is with lower end cover [10], welded bellows [8] between upper end cap [6] and the lower end cover [10], bellows [8] is to be that 25 bellows [8] is composed in series by 2 wave numbers, there is guide sleeve [9] to connect between two bellowss [8], upper end cap [6], bellows [8], be welded into a large displacement corrugated pipe assembly that is enclosed within valve rod [1] outside by argon arc welding between guide sleeve [9] and the lower end cover [10], lower end cover [10] is welded on the valve rod [1].Liner stuffing box packing between top cover [3] and the valve rod [1].Bellows [8], guide sleeve [9], upper end cover [6], lower end cover [10] are made up of stainless steel material.Top cover [3] is other to connect pressure gauge [11], and the joint of pressure gauge [11] and bellows [8] inner chamber communicate.

Claims

1, a kind of valve bellow seal with the dryvalve sealing, form and comprise upper valve body (7), there is valve rod (1) at upper valve body (7) center, the top of valve rod (1) is with upper end cap (6), upper end cap (6) is the cylindrical ferrule that step is arranged, upper end cap (6) is movingly with valve rod (1), upper end cap (6) is by top cover (3), on screw (4) reaches, following two soft circles (5) of filling out of sealing are fixed on upper valve body (7), valve rod (1) bottom is with lower end cover (10), lower end cover (10) is a cylindrical ferrule, welded bellows (8) between upper end cap (6) and the lower end cover (10), it is characterized in that: bellows (8) is to be composed in series by 2～4 bellowss (8), there is guide sleeve (9) to connect between two adjacent bellowss (8), guide sleeve (9) is middle round-meshed lasso, upper end cap (6), bellows (8), be welded into a large displacement corrugated pipe assembly that is enclosed within valve rod (1) outside between guide sleeve (9) and the lower end cover (10), lower end cover (10) is welded on the valve rod (1).

2, valve bellow seal as claimed in claim 1 is characterized in that bellows (8) is best to be composed in series by 2 or 3 bellowss (8).

3, valve bellow seal as claimed in claim 1 is characterized in that between upper end cap (6), bellows (8), guide sleeve (9) and the lower end cover (10) by roll welding or argon arc welding welding.

4, as claim 1,2 or 3 described valve bellow seal, it is characterized in that liner stuffing box packing between top cover (3) and the valve rod (1).

5,, it is characterized in that bellows (8), guide sleeve (9), upper end cap (6) and lower end cover (10) is made up of stainless steel material as claim 1,2 or 3 described valve bellow seal.

6, as claim 1,2 or 3 described valve bellow seal, it is characterized in that top cover (3) side connects pressure gauge (11), the joint of pressure gauge (11) and bellows (8) inner chamber communicate.