GB2173575A - Check valve - Google Patents

Abstract

A unitized check valve for use with corrosive fluid includes a generally cylindrical body (10). A valve seat (24) is disposed in the body around an aperture therethrough and a first set of angularly spaced apart arcuate flanges (46) depends from the outlet end. A valve disk (12) is coaxially associated with the seat and is adapted for axial movement to block and unblock the aperture in order to control the flow of fluid through the body. A valve retainer (16) has a second set of angularly spaced apart arcuate flanges (70). The flanges (70) of one of the sets extend generally radially inwardly and the flanges (46) of the other one of the sets extend generally radially outwardly. The flanges (70) of the second set are positionable between adjacent ones of the flanges (46) of the first set. A coil spring (14) bears against the valve disk (12) and the retainer and is responsive to flow fluctuations on the disk for thereby permitting movement of the disk. Alignment of the flanges (70) of the second set between the flanges (46) of the first set and rotation of the retainer (16) causes the flanges (70) of the second set to be engaged with the flanges (46) of the first set for thereby preventing axial displacement of the retainer so as to maintain the valve in assembled condition. <IMAGE>

Description

SPECIFICATION Check valve This invention relates to check valves and particularly, but not exclusively, to check valves for use with corrosive fluids or in corrosive environments. Check valves may be subjected to exposure by corrosive media when utilised as components of reciprocating pumps orwhen installed in-line in a piping system.

Other uses and insta I lations of check valves are well known and the present invention is not limited solely to use in corrosive media.

Stem-guided unitized check valves have been used in reciprocating pumps. Typically, in such a valve, a valve disk is guided by a stud and a sleeve. The sleeve is fastened to the valve seat and to a spring which biases the disk. Usually, the seat is webbed in orderto provide a base for the stud. Such check valves have been commercially successful but continue to suffer from several disadvantages. Firstly, the valve seat is retained in the fluid end ofthe pump in a tapered bore. The webbed seat varies in flexibility around its circumference so that there are tight and loose spots in the fit with the resu Itthat fluid washouts may occur.

Secondly, a webbed seat has a largerwetted perimeter that an open bore seat with the resultthatthe webbed seat has a greater pressure drop and therefore operates less efficientlythan an open bore seat.

Finally, the known valve assemblies of this type require threaded fastening. Threaded fastening is undesirable because the threads cannot tolerate much metal loss before their strength is compromised. Corrosion resistant th reads, on the other hand, are subjectto galling. Additionally, threads require machining operations and thereby added expense.

U.S. Patent No.2,649,277, of Blackford, discloses a check valve wherein a guard comprised of a resilient material is removably connected to the closure disk by the seating of pendent legs in a circumferential groove. The legs are angularly movableto permit foot projections thereof to be received within orto be removed from the groove. The guard is made from a resilient material which therefore may not be able to withstand the temperature extremes and fluctuations of the corrosive fluid. The patent disclosesthatthe valve components are threaded together, a feature which is undesirable with corrosive fluids and media.

There is no reference, in this U.S. Patent, to the disk being bottom guided. U.S. Patent 2,710,023, of Blackford et al, discloses another attempt to provide an interlocking between the components ofcheckvalve.

U.S. Patent 1,959,644 of Richardson, and U > S) Patent 2,904,065, of Butlin discloses valve assemblies wherein a retainer is made a snap-fit in the valve body. Such a snap-fit is undesirable, particularly when the valve is comprised of hard, inflexible materials.

It is an object of the present invention to provide an improved check valve which overcomes at leastsome ofthe problems and disadvantages of prior unitized check valves and which may be readily assembled and disassembled.

According to one aspect ofthe invention, there is provided a check valve or the like, comprising: a) an apertured generally cylindrical body including a fluid inlet and a fluid outlet including a valve seat; b) afirstsetofangularlyspaced apart arcuate flanges depending from said outlet; c) disk means coaxially associated with said seat adapted for axial movementto block and unblock said aperture andforthereby controlling theflowof fluid through said body; d) retainer means including asecondsetofangu- larly spaced apart arcuate flanges, the flanges of one of said sets extending generally radially inwardly and the flanges of the other one of said sets extending generally radially outwardly and the flanges of said second set being positionable between adjacent ones of the flanges of said first set; and, e) biasing means bearing against said disk means and said retainer means responsive to flowfluctuations on said diskforthereby permitting movement of said disk whereby alignment of the flanges of said second set between the flanges of said first set and rotation of said retainer means causes the flanges of said second set to become engaged with the flanges of said first setforthereby preventing axial displace mentofsaid retainer means and for maintaining the valve in operative condition.

According to another aspect of the invention,there is provided a check valve for corrosive environments and fluids, comprising: a) a generally cylindrical body comprised of a corrosion resistant material, said body having an aper turetherethrough providing an inlet and an outlet; b) a valve seat positioned in said aperture intermediate said inlet and said outlet; c) a plurality of angularly spaced apart arcuate first lock flanges integral with said body depending from said outlet; d) disk means comprised of a corrosion resistant material coaxially associated with said seat, said disk means being adapted for axial movement for blocking and unblocking said aperture and forthereby controlling the flow of fluid through said aperture; e) retainer means of an inflexible corrosionresistant metal-containing composition removably mounted to said outlet;; f) a pluralityofangularlysapced apartarcuate second lock flanges integral with said retainer means, said first flanges extending generally radially in a direction opposite to the direction in which said second lock flanges extend and said second lock flanges being positionable between adjacent ones of said first lock flanges; and, g) biasing means disposed between and bearing against said disk means and said retainer means for permitting axial displacement of said disk means in response to fluid flow fluctuations on said disk means whereby positioning of said second lockflanges between said first lock flanges and subsequent rotation of said retainer means causes said second lock flangesto become engaged with said first lock flanges for thereby preventing displacement of said retainer means and for maintaining the valve in operative condition.

Embodiments of the invention are described below, byway of example, with reference to the accompanying drawings, wherein: Figure 7 is an exploded perspective assembly drawing ofa checkvalve embodying the invention; Figure 2 is a perspective view ofthe valve of Figure 1 in an assembled condition; Figure 3 is a cross-sectional viewtaken along the line 3-3 of Figure 2 and viewed in the direction ofthe arrows; and, Figure 4 is a cross-sectional view of another check valve embodying the invention.

Referring to Figures 1 to 3, a unitized checkvalveV, as best shown in Figures 1 and 2, includes a valve body10, a valve disk 12, a biasing spring 14and a valve retainer 16. These components are manufactured ofstainless steel orothersuitably hard nonresilient material which resists corrosion bythefluid being controlled and by the surrounding environment. Preferably, the body 10, the disk 12 and the retainer 16 are manufactured by the investmentcasting procedure in order to reduce the need for machining the parts and to avoid internal stresses.

As best shown in Figure 3, body 10 is generally of cylindrical shape and has a central longitudinal aperture 18 therethrough providing an inlet opening 10 and an outlet opening 22, as best shown in Figure 1.

Outlet opening 22 includes a circumferential angularly disposed portion 24 providing a valve seat. Valve disk 12 includes a corresponding angularly disposed portion 26 which seats with portion 24 and thereby seals outletopening 22 by blocking aperture 18.

As bestshown in Figure 3, valve disk12 has downwardly depending guide members 28 extending from the lower surface 30 thereof. Guide members 28 have a lower end 31 and a tapered side portion 32 permitting the members 28 to be easily positioned within the aperture 18 of body 10. It can be noted thatthe downwardly depending members 28 have a peripheral surface 34aligned with the wall ofthe body 10 provided by aperture 18 and thereby the valve disk 12 is guided during axial displacement by .

the engagement ofthe peripheral surfaces 34 with the wall of the aperture 18. In this way, axial movementof the valve disk 12 to block and unblock the outlet opening 22 can be accomplished withoutthevalve disk 12 becoming canted or otherwise so misaligned that the disk 12 will not seat on the portion 24 and thereby not seal the outlet opening 22. Use of guide members 28 provides a bottom guide for disk 12 which avoids the stem-guided problems of priorart valves and also eliminates the needfora sleeve. Preferably,four equiangularly disposed downwardly depending guide members 28 are provided forthe disk 1 2although those skilled in the art will appreciate that the number of guide members 28 will be à function of the size ofthe aperture 18.The tapered portions 32 facilitate the insertion ofthe guide members 28 into the aperture 18 during the initial assemblywnilethe peripheral surfaces 34 maintain proper alignment of the disk 12 in the aperture 18 during use ofthevalve.

Disk 12 furthermore includes an upwardly extending circular support member36 coaxial with the longitudinal axis of aperture 18. Outwardly extending flange 38 of disk 12 cooperates with supportmember 36to provide annular groove 40 which receives one end ofthecoil spring 14. The coil spring 14hasan internal diameter at least corresponding to the diameter ofthe support so thatthe end of spring 14 is seated in the groove 40. The other end ofthe coil spring 14 bears againstthe retainer 6 and thereby substantialforce is exerted on the disk 12 for urging the-disk 12 2 to blocktheoutletopening 22. Naturally, the spring force of spring 14 will be selected with regard to the pressure being controlled.

As best shown in Figure 1, circumferential flange or shoulder 42 extends outwardly from the outerwall 44 of body 10. Flange 42 is axially spaced from outlet opening 22, forreasonsto be explained. First locking flanges 46 are, preferably, equiangulariydisposed about outlet opening 22 and extend radially outwardlyfrom axially extending wall portion 48. Lock flanges 46 have a bottom surface 50 which is spaced a pre- selected distance above the uppersurface 52 of flange 42; for reasons to be explained. The flanges46 are arcuate in-shape and each flange 46 subtends a preselected portion of a circle. Theflanges 46 have a peripheral arcuate surface 54 which is spaced radially inwardlyfromthe peripheral surface 55 of flange 42.

Although three lockflanges 46 are shown in Figure 1, those skilled in the art will realizethata greater or fewer numberofflanges 46 may be used to practice the invention depending upon the diameter ofthe body 10.

As best shown in Figure 1, retainer 16 resembles a basket or a cage and has a lower generally circular rim member 56 connected to upper support 58 by legs 60.

Itcan be noted in Figure 1 that upper support 58 includes hexagonal recess 62which is centrally located and adapted for receipt therein of an Allen wrench orthe like. The aperture 64 permits fluid to drain from recess 62. Aperture 64 has a diameter less than recess 62 in order to preventthe wrench from extending too far into the valve V. The legs 60 are, preferably, equiangularly disposed about rim 56 and a substantial open area 65 extends between adjacent legs 60 thatfluid issuing from outlet opening 22 may leave the valve Vto be collected or otherwise disposed of and thereby prevent hindrance in the operation ofthe valve V.

Rim 56 has an outer peripheral surface 66 and an inner surface 68 radially inwardly spaced a constant distance from outer surface 66. Second lockflanges 70 extend radially inwardlyfrom inner surface 68.

Second lock flanges 70 are equiangularly disposed about inner surface 68 and a lockflange 70 is provided for each oflockflanges46. Each ofthesecond lock flanges 70 has a first end 71 provided by the axially extending wall 74 of the associated leg 60. It can be noted that legs 60 have an inner wall 75 aligned with innersurface 77 of flanges 70 in order to provide strength for retainer 16. Stop members 76 extend radially inwardly from innerwall 68 and provide a second end 78for each of the second lockflanges 70.

The arcuate portion of the second lock flanges 70 between the ends 72 and 78 subtends a portion of a circle corresponding to the portion subtended byfirst lockflanges 46. In this way, each ofthefirst lock flanges 46 may be-received between the ends 72 and 78 of lockflanges 70 so that retainer 16 maybe seated on upper surface 52 of shoulder 42. The shoulder 42 thereby prevents the retainer 16 from being axially spaced too great a distance from lock flanges 46.

The arcuate area 80 provided byinnersurface77 between the stop members 76 and the wall 82 ofthe legs 60 is of sufficient size to permit a first lockflange 46to be positioned therein. The wall member 82 of the legs 60 is parallel to the wall member 74 and provides a stop or alignment mechanism when the retainer 16 is being aligned on the body 10. It can be noted in Figure3thatinnerwall member 75 is aligned with wall portion 48 of body 10 and thereby maintains positive positioning of the retainer 16 on the body 10.

As best shown in Figure 3, rim 56 has an upper surface 86 and a lower parallel surface 88 disposed adjacent upper surface 52 of body 10. Lockflange46 has a lower surface 50 which is spaced from upper surface 52 a distance at least equal to the distance separating surfaces 86 and 88. In this way, the stop members 76 will pass undertheflanges46 upon rotation of retainer 16 during assembly and dis assembly ofthe valve V. The retainer 16 maythere fore be attached to the body 10 by aligning the open ings 80 with the flanges 46 and by depressing and rotating the retainer 16 so thattheflanges 46 are positioned in locking engagement underneath the second lock flanges 70.

It will be appreciated that first flanges 46 and second flanges 70 form part of a bayonet connection between the body 10 and retainer 16. The bayonet connection facilitates assembly and disassembly of the valve because the retainer is removably con nected to the body by merely pushing the retainer axially and rotating the retainer so that the flanges of the retainer engage the flanges extending from the body. The valve is thus easily and quickly assembled and disassembled with the mere turn of a wrench which is advantageous where the valve is used in tightly confined spaces.

As best shown in Figure 3, retainer 16 has a central tapered spring mount 92. The spring mount 92 main tains proper positioning ofthe coil spring 14 around the axis of retainer 16 and thereby cooperates with the support 36 for assuring only axial displacement of disk12.

The valve shown in Figure 4 is similar in many respects to the valve V of Figures 1-3. The valve of Figure4 is an in-line valve and includes avalve body which includes co-axial inlet and outlet branches 96 and 98 (shown only in part) which in use are con nected with aligned parts of a fluid supply lineto form, in the complete installation, parts ofthe supply line. The valve body further includes a generally cylin drical valve body portion 94 which extends atan oblique angle from the fluid supply line of which branches 96 and 98 form part.

Body portion 94 has bottom closure plate 104 separating a valve chamber 102 within body portion 94from fluid supply line 96. An aperture 106 isformed in plate 104 and in the open condition of the valve fluid can flow from inlet branch 96 through aperture 106 into chamber 102 and thence, through an open ing 100, into the outlet branch 98. Associated with aperture 106 is a valve disk 108 which issimilarto disk 12 ofthevalve of Figures 1 to 3. Avalyeseat 110 is positioned downstream of plate 104 and seat 110 has a sealing surface 112 which is engaged by a corres ponding sealing surface 114 of disk 108. Disk 108 has a plurality of guide members 116 extending from the bottom surface 1 18thereof adapted for bearing againstthewail of aperture 106 during longitudinal axial displacement of disk 108.The valve disk 108 is urged against seat 110 buy a coil spring 124.

Disk 108 has support member 120 extending from the upper surface 122 thereof. Support member 120 has a diameter less than the diameter of uppersurface 122. The diameter of support member 120 corresponds to the internal diameter of coil spring 124 and thereby support member 120 extends into and is aligned by coil spring 124.

Body 94 includes an aperture 126 therein connecting chamber 102 with secondary chamber 128.

Spring l24extendsthroughaperture 126 into cham- ber 128 and is seated by a support member 130 of a retainer 132. In this way, spring tension is maintained on the valve disk 108 so thatthe disk 108 is axially moved in responseto pressure fluctuations in feed line 96. The support members 120 and 130 maintain proper alignment of spring 124 and thereby prevent dislocation of the disk 108 during displacement of the disk 108.

A plurality of lockflanges 134 are equiangularly disposed about body 94 at the upper end thereof.

Although only one of the flanges 134 is shown in Figure4,the plurlity oflockflanges 134 are similarto the flanges 46 of the body 10 with the exception that the lock flanges 134 extend generally radially inwardly.The lock flanges 134 are arcuate in plan and each of the lock flanges 134 subtends a preselected segment of a circle. Each of the lock flanges 134 has a recess 136 therein adapted for receiving second lock flange 138 extending generally radially outwardly from retainer 132. As previously described for the valve V of Figures 1 to3,thereisalockflange 138extending from the retainer 132foreach ofthe lockfianges 134.

The flanges 138 subtend a segmentof a circle substantially equal to the segment subtended by the lock flanges 134 so thatthe flanges 138 may be engaged with the flanges 134to prevent unintended axial displacement of the retainer 132. As described forvalve V and retainer 16, the space between adjacent lock flanges 138 is open, as is the space between adjacent flanges 134 and the opening 140 between adjacent flanges 138 is sufficient to permit the openings 140to receive a lockflange 134. In this way, the openings 140 maybe aligned with the lockflanges 134during assembly. The retainer 132 is then pressed downwardly and rotated, until the flanges 138 are secured by the flanges 134.

The secondary chamber 128 has a smooth cylindrical wall co-axial with the valve disc and valve seat and the portion of retainer 132 within chamber 128 includes a cylindrical portion which fits closely within this cylindrical wall and is divided by a circumferential groove into two axially spaced flanges 142 and 144. Disposed in this groove between flanges 142 and 144 is a seal 146, preferably in the form of an '0' ring.

0being 146 prevents fluid from leaking part retainer 132 and ensures that fluid exits from chamber 102 only through outlet branch.

A hexagonal recess 148 is provided in retainer 132 to permit the retainer 132 to be rotated by the insertion of an Allen wrench, orothersuitable member.

The spring 124 may be selected to permit the retainer 132 to be rotated by hand pressure alone. Should the line pressure of the supply line 96 be large, then the spring 124 may have sufficienttension to require the use of a wrench. Consequently,the retainer 132 may be inserted or removed even when the valve of Figure 4 is in a confined area. This is also true for the valve V and thereby use of either valves is appropriate in those installations wherein space is limited.

In each of the embodiments described, a unitized Check valve is provided which may be easily and quickly assembled and disassembled and isthmus advantageous for those situations wherein the valve is subject to corrosive media. The components of.the check vaive in each case are comprised of stain less steel or other similar hard inflexible corrosion .

- -resistant materials able to with stand the severe tem perature fluctuations normal for such environments.

The valves described do not use screw threads and -thus avoid the problems of galling and/or metal loss, noiido they utilise press fit connections.

Each of the unitized check valves describedwith reference to the drawings is comprised of metallic parts which may be repeatedly assembled and dis assembled with minimum effort.

As illustrated by the valves of Figures 1 to 3 and 4, the invention may be embodied in-a unitized check valve which is adapted for terminal end operation or in a--unitized valve adapted for in-line operation,

Claims (26)

1. Acheck valve or the like, comprising: a) an apertured generally cylindrical body-in.ctuding a fluid inlet and a fluid outlet including a valve seat; b) a firstset of angularly spaced apart arcuate flanges depending from said outlet; c) disk means coaxially associated with said seat a-dapted-for axial movementto block-and unblock said aperture and forthereby controlling the flqw of - fluid through said body; d) retainer means including a second set of angu larly spaced apart arcuateflanges, the flanges pf one of said sets extending generally radially inwardly and -theflanges ofthe other one ofsaid sets extending generally radially outwardly and the flanges of said second set being position able between adjacent ones óftheflanges of said first set; and e) biasing means bearing against said disk means and said retainer means responsive to flow fluctua tions on said diskforthereby permitting movement of said disk whereby alignment of the flanges of said second set between the flanges of said first setand rotation of said retainer means causes the flanges of said second setto become engaged with the flanges of said first set for thereby preventing axial displace ment of said retainer means and for maintaining the valve in operative condition.

2. A check valve as claimed in claim 1, wherein at least a first disk guide extends from said disk means aligned with said aperture for guiding said disk means during displacement thereof.

3. Acheck valve as claimed in claim 1 or claim 7, wherein: a) said disk means includes an upper and a lower surface; and, b) a plurality of guide members extend from said lower surface and are aligned with said aperture for guiding said disk means during displacement thereof.

4. Avalve as claimed in claim 3, wherein: a) said valve seat has an angularly disposed cir cumferential portion; and b) said lower surface has an angularly disposed peripheral portion aligned with said circumferential portion and adapted for sealing engagement there with whereby said disk means blocks said aperture.

5. A check valve as claimed in claim 3 or claim 4, wherein positioning means extend from said upper surface and are engaged with said biasing means for maintaining alignment of said biasing with said disk means.

6. A ckeck valve as claimed in claim 5, wherein: a) said biasing means includes a coil spring; and, b) said positioning means includes a generally cir cular member having a diameter substantially equal to the internal diameter of said coil spring for seating said coil and thereby positioning and aligning said coil spring.

7. A check valve as claimed in claim 1, wherein the flanges of said second set extend generally radially inwardly and the flanges of said first set extend gen erally radially outwardly.

8. A check valve as claimed in claim 7, wherein: a) a circumferential flange member extends around the exterior of said body; and, b) said flange member is axially spaced from the flanges of said first set by a distance substantially equal to the thickness of the flanges of said second set for permitting the flanges of said second set to be aligned with the flanges of said first set during rota tion of said retainer means.

9. A check valve as claimed in claim 8, wherein: a) said retainer means includes a cage having an outer wall surface and an inner wall surface; and, b) the flanges of said second set extend from said inner wall surface.

10. A check valve as claimed in claim 9, wherein a plurality of stop means extend from said inner wall surface for preventing excessive rotation of said re tainer means and for therefore facilitating alignment of the flanges of said second set with the flanges of said first set.

11. A check valve as claimed in claim 1, wherein the flanges of said first and second sets are equiangu larly disposed about said retainer means.

12. A check valve as claimed in claim 1, wherein the flanges of said first set extend generally radially inwardly and the flanges of said second set extend generally radially outwardly.

13. A check valve as claimed in claim 12, wherein at least a first guide means extends from said disk means for guiding said disk means during displace ment thereof.

14. A check valve as claimed in claim 12, wherein: a) said disk means includes an upper and alower surface; and, b) a plurality ofleg members extend from said lower surface and are aligned with said aperture for guiding said disk means during displacement thereof.

15. Acheckvalve as claimed in claim 14,wherein positioning means extend upwardly from said upper surface and are engaged with said biasing means for aligning said biasing means on said disk means.

16. Acheckvalve as claimed in claim 15,wherein: (a) said biasing means includes a coil spring; and, b) said positioning means includes an upwardly extending generally circular member having a diameter less than the diameter of said spring means for seating said spring means.

17. Acheckvalve as claimed in any preceding claim, wherein said retainer is of an inflexible corrosion-resistant metal-containing composition.

18. A check valve for corrosive enviornments and fluids, comprising: a) a generally cylindrical body comprised of a corrosion resistant material, said body having an aperture therethrough providing an inlet and an outlet; b) a valve seat positioned in said aperture intermediate said inlet and said outlet; c) a plurality of angularly spaced apart arcuate first lock flanges integral with said body depending from said outlet; d) disk means comprised of a corrosion resistant material coaxially associated with said seat, said disk means being adapted for axial movement for block- ing and unblocking said aperture and forthereby controlling the flow of fluid through said aperture; e) retainer means of an inflexible corrosionresistant metal-containing composition removably mounted to said outlet;; f) a plurality ofangularlyspaced apartarcuate second lock flanges integral with said retainer means, said first flanges extending generally radially in a direction opposite to the direction in which said second lock flanges extend and said second lock flanges being positionable between adjacent ones of said first lock flanges; and, g) biasing means disposed between and bearing against said disk means and said retainer means for permitting axial displacement of said disk means in response to fluid flow fluctuations on said disk means whereby positioning of said second lockflanges between said first lock flanges and subsequent rotation of said retainer means causes said second lock flanges to become engaged with said first lock flangesforthereby preventing displacement of said retainer means and for maintaining the valve in operative condition.

19. Acheckvalve as claimed in claim 18,wherein said first lock flanges extend generally radially outwardly and said second lockflanges extend generally radially inwardly.

20. A check valve as claimed in claim 19, wherein a circumferential shou Ider extends around said body and is axially spaced from said first lock flanges for providing a seatforsaid retainer means.

21. Acheckvalve as claimed in claim 18,wherein at least a first guide member extends from said disk means into said aperture for guiding said disk means during- displacement thereof.

22. Acheckvalve as claimed in claim 20,wherein: a) said disk means includes an axially extending support; and b) said biasing means includes a coil spring having a first end engaged with said support and a second end engaged with said retainer means.

23. Acheckvalve as claimed in claim 19, wherein said first lock flanges extend generally radially inwardly and said second lock flanges extend generally radially outwardly.

24. Acheckvalve substantially as herein described with reference to, and as shown in, Figures 1 to 3 of the accompanying drawings.

25. A check valve substantially as herein described with reference to, and as shown in, Figure 4 of the accompanying drawings.

26. Any novei feature or combination offeatures disclosed herein.