CA1056793A - Ball valve - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A ball valve having a valve body, a main flow passage therethrough, a lateral bore extending generally perpendicularly through the passage, and a unitary ball valve member received in the lateral bore. The ball valve member has a spherical ball portion with an aperture therethrough and a pair of circular sealing heads, one on each side of the ball portion. Each of the sealing heads carries a seal which is slidably and sealingly engageable with the walls of the lateral bore. The sealing heads are of substantially equal diameter so that pressure forces acting on the ball valve member which tend to move the latter axially within the bore are balanced. A seal body is insertable into a main flow passage of the valve body from one end thereof for sealingly engaging the ball portion after the ball valve member has been installed in the lateral bore.

Description

~.~35~793 BALL VALVE

Back round of the Invention g This inyention relates to a valve and m~re particularly to a combination valve and manifold assembly for a co~pressed air storage tank or the like.
Generally, it i~ desirable that a compressed air storage tank have as few openings as possible therein. However, it is often necessary to provide ports or a pressure gauge and for a safety relief valve as well as a main air outlet. Heretofore, manifold assemblies were known which provided a ma~n air outlet, a shutoff valve for the outlet, and other outlet ports for connection of a pressure gauge, a pressure relief valve, or the like. In one of these prior art manifold assemblies, such as shown in U.S.
patent 3,231,236, a slide valve is used to block the flow from the main outlet. This ~lide valve is, however, subject to wear and leakage and it severely restricts flow through the main outlet.
In the manifold assembly of the present invention, a ball valve is used as the flow shutoff valve. The advantages of ball valves ti.e., low pressure drop and high flow through the valve, and the fast opening aAd closing action of the valve) are well known. However, known ball valves, when subjected to fluid pressure often bind in their valve seats. It is also necessary that the ball valve membe~ be sealingly mated with its valve seat.

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In some ball valves, unequal pressure forces exerted on opposite sides of the ball valve member caused it to bind on its valve seat and to unevenly contact its seat thus resulting in leakage, and made the valve difficult to oper-ate. In some instances, these unbalanced pressure forces caused damage to the valve. Also, the seals and the con-struction of many ball valve designs are complicated.
Summary of the Invention Among the characteristics of the preferred embod-iment of this invention may be noted the provision of a ball valve which has a minimal number of parts and seals;
the provision of such a valve which does not stick or bind in its valve body when subjected to relatively high operat-ing pressures; the provision of such a valve in which its seals are not subject to damage upon turning of the valve;
the provision of such a valve which has a relatively low pressure drop therethrough and which enables high flow rates therethrough; the provision of such a valve which may be molded of synthetic resin material and which is not sub-ject to corrosion; the provision of such a valve which may be readily adjusted to infinitely vary the flow rate therethrough and which may be readily and reliably opened and closed; the provision of such a valve which is of light weight, inexpensive to manufacture, easy to install, and reliable in operation. Other object and features of this invention will be in part apparent and in part pointed out hereinafter.
Briefly, a valve of this invention comprises a valve body having a main flow passage therethrough and a bore of generally circular cross-section in the valve body extending generally perpendicularly through the passage, one n ~J 2 1~5~i793 end of the passage constituting an inlet and the other end of the passage constituting an outlet. A unitary ball valve member is received in the bore, this ball valve member being rotatable about the longitudinal axis of the bore between a closed position in which it blocks flow through the flow passage and an open posi-tion in which it permits flow through the flow passage.
The ball member comprises a generally spherical ball portion having an aperture therethrough constituting a portion of the flow passage when the ball valve member is in its open position, and a pair of circular sealing heads, one on each side of the ball portion. Each of the sealing heads carries a seal which -slidably, sealingly engages the walls of the bore so as to seal the ball valve member relative to the valve body and to permit rotation and axial movement of the ball valve member within the bore between its opened and closed positions.
The sealing heads are of substantially the same diam-eter so that pressure forces acting on the ball valve member which tend to move the latter axially within the bore are balanced. Means external to the valve body is provided at each end of the ball valve member for retaining the ball valve member in the bore and for permitting limited axial movement of the ball valve member in the bore by engagement with the valve body. The valve further includes seal means insertable into the ios67s3 flow passage from one en~ thereof, the seal means comprising a seal body having a longitudinal bore therethrough constituting a portion of the flow passage, and an end seal carried on the inner end of the seal body engageable with the ball portion. The retaining means permits limited axial movement of the ball valve member in the bore to a po~ition in which the end seal is sealingly seated on the spherical ball portion for preventing leakage around the ball portion to the outlet when the ball valve member is in its closed position.
Brief Description of the Drawings Fig. 1 is a plan view of a manifold assembly of this invention;
Fig. 2 is a longitudinal C~Qss-seCtiOn taken on line 2--2 of Fig.-l of the manifol~ assembly showing ..
a ball-type shutoff valve, the latter being shown in its closed posîtion blocking flow through the manifold assembly;
Fig. 3 is a vertical cross section of the manifold assembly taken on line 3--3 of Fig. l; and Fig. 4 is a bottom view of the manifold assembly shown in Fig. 1 with a portion of the manifold assembly shown in cross-section to illustrate details of an over~ressure safety relief valve.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

10567~3 Description of a Preferred Embodiment Referring now to the drawings, a valve of this invention, generally indicated at 1, is shown to comprise a valve body 3 (also referred to as a manifold body) having a longitudinal bore 5 therethrough, portions of which constitute a main flow passage through the valve body, and a lateral bore 7 (see Fig. 2) of generally cir-cular cross-section extending generally perpendicularly through bore 5. One end of bore 5 (i.e., the left end as shown in Fig. 2) constitutes an inlet end and the other end thereof constitutes an outlet end. The inlet end of bore 5 is threaded, as indicated at 8, for being in-stalled on a male nipple (not shown) of an air compressor tank or the like (also not shown) whereby compressed air or other fluid enters the inlet end of the bore (as shown by the arrows in Fig. 2). As generally indicated at 9~ a unitary ball valve member is received within bore 7 for rotation between a closed position (as shown in Fig. 2) in which it blocks flow through bore 5 and an open po`sition (not shown) in which it permits flow through the bore. Thus, this ball valve constitutes a shutoff valve. Ball valve member 9 comprises a generally spheri-cal ball portion 11 having an aperture 13 therethrough.
This aperture is in alignment with bore 5 when the ball valve member is in its open position and thus constitutes a portion of the main flow passage through which air and other fluid may flow through valve 1 with minimal 1056~93 restriction by the ball valve. The ball valve member further includes a pair of circular heads 15a, 15b, one on each side of ball portion 11. Each of these heads carries an O-rlng seal 17 in a circumferential groove 18 with the O-ring slidably, sealingly engaging the wall of bore 7 so as to seal the ball valve member relative to the valve body and to permit rotation of the ball valve member about the longitudinal axis of bore 7 between its opened and closed positions. Sealing heads 15a, l5b are of substantially the same diameter (i.e., the diameter of bore 7) so that the pressure forces within valve body 3 acting on the ball valve mem-ber which tend to move the latter axially within bore 7 are balanced. This feature permits the ball valve member to readily be rotated when subjected to pressure without sticking or binding in bore 7 and it insures that the ball portion will remain seated on its seals.
As is indicated at 19, a fixed flange is provided at one end of valve member 9 on the outside of head 15a and a stem 23 of part-circular cross-section extends from ball portion 11 opposite flange 19. A re-tainer disk 21 having a part-circular opening 22 therein is keyed on stem 23 and is remova-bly secured in place on . the stem by a snap ring 25. Thus, flange 19 and disk 21 retain the ball valve member within bore 7, but the clear-ances between flange 19 and body 3 and between disk 21 and -the body permit limited axial movement of the ball valve member within the bore for purposes as will appear.

~OS6793 A seal member, as generally indicated at 26, is insertable (i.e., threadable) into bore 5 from one end thereof (e.g., the right or outlet end of bore 5 as shown in Fig. 2). Seal member or body 26 has an axial bore 27 therethrough constituting a portion of the main flow passage, and it has an 0-ring seal 29 carried in annular groove 30 on its inner end surrounding bore 27.
As indicated at 31, the inner end of seal body 26 sur-rounding bore 27 is tapered to accommodate a portion ~f spherical ball portion 11 and to protect O-ring seal 29 from damage (i.e., from being cut or pinched) as the ball valve member is opened and closed to move aperture 13 over the O-ring. Seal body 26 further has a circum-ferential packing O-ring seal 32 received in a groove 33 on the outer surface of the seal member adjacent its inner end. Seal member 26 is threaded into bore 5 after installation of ball valve member 9 in lateral bore 7 so that seal 29 sealingly engages the spherical surface of ball portion 11 thereby to prevent leakage around the ball portion to the outlet end of passage 5 when the ball valve member is in its closed position. Packing seal 32 seal-ingly engages the valve body downstream from bore 7 so as to prevent leakage between seal member 26 and the valve body.
As previously mentioned, ball valve member 9 is permitted to move axially in bore 7 through a limited distance by re-taining flange 19 and retaining disk 21. This permits the valve member to move axially within bore 7 to a position in which the ball portion 11 is uniformly sealingly seated on end 0-ring seal 29. Because the pressure forces on the ball valve member are balanced, there is little tendency for the seal to leak. It will be noted that only one seal engageable with the ball portion 11 is required to seal the ball valve member relative to the main flow pass-age. Thus, either end of bore S could constitute an inlet.
As indicated at ~, ball valve member 9 has a handle for facilitating manual turning of the ball valve member between its closed and opened positions, Pref-erably, valve body 3, ball valve member 9, disk 21, and seal member 26 are molded of suitable synthetic resin material. The outlet end of bore 5 in valve body 3 is internally,threaded as indicated at 34, and seal body 26 has external threads 35 thereon threadably engageable with threads 34. As indicated at 36, bore 27 in seal member 26 is of hexagonal cross-section so as to receive a driv-ing wrench for threading the seal member into the outlet end of bore S and valve body 3. After seal body 26 has been properly positioned in bore 5 with its inner end seal 29 seated on ball portion 11 of ball valve memher 9, a screw 37 is threaded into the seal body through valve body 3 thereby to fixedly hold the seal body in the valve body. Disk 21 has two spaced stops 38a, 38b (see rig. 4) positioned on opposite sides of a portion of valve body 3 for engaging the above-mentioned portion of the valve body as the valve member is turned between ~056793 its open and closed pOSitions. Thus, these stops permit limited rotation (e.g., approximately 90) of the valve member so as to insure that the valve member may not be rotated past its opened and closed positions.
Valve body 3 carries indicia, as indicated at I, for indicating the position of the ball valve member (see Fig. 1). With valve 1 molded of synthetic resin mate-rial, corrosion of the valve is substantially eliminated and sealing tape or other sealant is not required for insuring leaktight connections of the valve.
Further in accordance with this invention, valve 1 is shown to be a part of a manifold assembly for an air compressor storage tank (not shown) or the like.
Valve or manifold body 3 is shown to have two outlet nipples 39 and 41 in communication with bore 5 within the valve body intermediate lateral bore 7 and the inlet end of bore 5. As indicated at 43, these nipples have external screw threads thereon for connection thereto of a pressure gauge, a pressure actuated switch for con-trolling operation of an air compressor, or the like.
Each of these nipples has a respective tubular metal stiffener 45, 47 (see Fig. 3) pressed into the bore of each nipple to provide additional strength for the nipples to enable them to resist bending and shock loadin~.

~1)5~;793 As generally indicated at 49 in Figs. 2 and 3, a safety pressure relief valve is provided in the manifold assembly of this invention for relieving pres-sure from within longitudinal bore 5 of valve body 3 up-stream from bore 7. It will be understood that with valve body 1 installed on an air compressor storage tank or the like, safety pressure relief valve 49 will auto-matically relieve pressure from within the tank upon the pressure exceeding a predetermined pressure level. As indicated at 51, a boss is formed on valve body 5 hav-ing a blind chamber 53 therein. This chamber has a base 55 having a port 57 therein in communication with bore 5 upstream (i.e., toward the inlet end of bore 5) from bore 7. An annular raised seat 59 surrounds this port.
A poppet valve 61 is housed in chamber 53 and is movable toward and away from the valve seat 59 between a closed position in which it sealingly engages the valve seat and an open position in which it is clear of the valve seat. The poppet member is of generally polygonal (i.e., square) cross-section (see Fig. 4) and has rounded cor-ners 63 which slidably engage the inner walls of the chamber for guiding the valve 61 within the chamber as it moves toward and away from the valve seat 59 between its open and closed positions. The valve also has flat wall portions or sides 65 spaced from the inner walls of the chamber thereby to provide channels or passages 66 for exhausting fluid (e.g., air) from port 57 when the poppet valve is clear of valve seat 59. As indicated at 67, a resilient pad of suitable elastomeric material or the like is carried on the bottom face of the poppet valve mem-ber and is sealingly engageable with seat 59 thereby to B lo ~056793 seal the valve member relative to the seat when the valve member is closed. A plug nut 69 is threaded into the open end of chamber 53 and a compression coil spring 71 is interposed between poppet valve member 61 and the plug nut so as to bias the former toward its closed position in which it is seatea on valve seat 59 to bloc~ flow from port 57. Upon pressure in bore 5 increasing above the predetermined level, a pressure force is exerted on the poppet valve member sufficient to overcome the bias of spring 71 and to open the poppet valve member (i.e., move it clear of valve seat 59) thereby to permit air to be vented from port 57. Plug nut 69 has a vent port 73 through which air vented from 57 is exhausted to the atmosphere. It will be understood that plug nut 69 and boss 51 are so structured that the plug nut cannot be threaded into chamber 53 so as to fully compress the coils of the spring 71 to rigidly hold the poppet valve member in its closed position against valve seat 59. As indicated at 75, poppet valve me~ber 61 has lugs at each of its corners 63 ~hich extend end~ise from the Po2pet valve member toward tne plug nut. Lugs 75 are of such length as to engage the inner end face of plug nut 69 as the poppet valve member is moved from its seat 59 so as to prevent the coils of spring 71 from being fully compressed and to prevent the poppet valve member from sealingly engaging the inner end of the plug nut. This insures that upon the pressure in ~ S~ 3~
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bore 5 exceeding the above-mentioned predetermined pressure level, the poppet valve member will open and air will be vented t~rough port 57 to flow around the flat sides 65 of the poppet valve member, between lugs S 75, through the coils of spring 71, and out vent port 73 in plug nut 69.
Plug nut 69 may be adjustably threaded into and out of chamber 53 thereby to vary the compression or preload of spring 71. By selectively varying the preload on the spring, the-pressure level in bore 5 which effects opening of poppet valve member 61 may be adjusted or calibrated. A stop nut 77 is threaded on plug nut 6~. With the plug nut in a desired position, stop nut 77 may be threaded down to engage the outer end of boss 51 thereby to lock the plug nut in position.
It will be understood that relief valve 49 may be calibrated at the factory to relieve pressure at a specified level.
-In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.
As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter con-tained in the above description or sllown in the accom-panying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims (12)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A valve comprising a valve body having a main flow passage therethrough and a bore of generally circular cross-section in said valve body extending generally perpendicularly through said passage, one end of said passage constituting an inlet and the other end of said passage constituting an outlet, a unitary ball valve member received in said bore, said ball valve member being rotatable about the longitudinal axis of said bore between a closed position in which it blocks flow through said flow passage and an open position in which it permits flow through said flow passage, said ball valve member comprising a generally spherical ball portion having an aperture therethrough constituting a portion of said flow passage when said ball valve member is in its open position, and a pair of circular sealing heads, one on each side of said ball portion, each of said sealing heads carrying a seal which slidably, sealingly engages the walls of said bore so as to seal said ball valve member relative to said valve body and to per-mit rotational and axial movement of said ball valve mem-ber within said bore, said sealing heads being of substan-tially the same diameter so that pressure forces acting on said ball valve member which tend to move the latter axially within said bore are balanced, means external to said valve body at each end of said ball valve member for retaining said ball valve member in said bore and for permitting limited axial movement of said ball valve member in said bore by engagement with said valve body, and seal means (claim 1 continued) insertable in said flow passage from one end thereof, said seal means comprising a body having a longitudinal bore therethrough constituting a portion of said flow passage, and an end seal carried on the inner end of said seal body engageable with said ball portion, said retaining means permitting limited axial movement of said ball valve member in said bore to a position in which said end seal is sealingly seated on said spherical ball portion for prevent-ing leakage around said ball portion to said outlet when said ball valve member is in its closed position.

2. A valve as set forth in claim 1 wherein each of said sealing heads has a circumferential groove there-around and an O-ring received in said groove constituting said seal carried by said sealing head.

3. A valve as set forth in claim 1 further comprising means for fixedly securing said seal body relative to said valve body.

4. A valve as set forth in claim 3 where in said securing means comprises a screw threaded through a portion of said valve body for engagement with said seal body.

5. A valve as set forth in claim 1 wherein said ball valve member further includes a handle at one end thereof, and a stem portion extending endwise from the other end of said ball valve member for extending out beyond said valve body when said ball valve member is received (claim 5 continued) within said bore, and wherein said retaining means com-prises a flange at said one end of said ball valve member adjacent said handle engageable with said valve body so as to limit inward movement of the ball valve member into the bore and a removable flange releasably secured to said stem portion when said ball valve member is received in said bore and engageable with said ball valve body to prevent removal of said ball valve member from said bore.

6. A valve as set forth in claim 5 wherein said removable flange includes means for limiting the rotation of said ball valve member substantially between its open and closed positions.

7. A valve as set forth in claim 1 further having pressure relief means disposed between the inlet end of said passage and said ball valve member for relieving pressure from the inlet in the event the pres-sure level in the inlet exceeds a predetermined pressure level.

8. A valve as set forth in claim 7 having a packing seal carried on the side of the said seal body sealingly engageable with said valve body so as to pre-vent leakage between said valve body and said seal body.

9. A valve as set forth in claim 7 wherein said valve body includes a chamber, a port in said valve body intermediate said inlet end and said ball valve member for communication between said flow passage and said chamber, a valve seat surrounding said port, and wherein said pressure safety relief means comprises a relief valve member engageable with said valve seat and movable toward and away from said valve seat between a closed position in which said relief valve member seal-ingly engages said seat and an open position in which the relief valve member is clear of said seat, compres-sion coil spring means biasing said relief valve member toward said seat, and closure means for said chamber comprising a nut threadably inserted into said chamber for engagement with said compression coil spring, said nut having a port therein for venting air from within said chamber.

10. A valve as set forth in claim 9 wherein said relief valve member is of generally polygonal cross-section and has a plurality of rounded corners slidably engageable with the walls of said chamber for guiding the valve member within the chamber as it moves toward and away from said valve seat between its opened and closed positions, said relief valve mem-ber having peripheral wall portions spaced from the walls of said chamber to provide a passage for the flow of air from said port around said relief valve member when the latter is in its open position.

11. A valve as set forth in claim 10 wherein said relief valve member has a plurality of lugs spaced from one another and engageable with said nut so as to prevent said valve member from sealingly engaging said nut so as to prevent sealing of said vent port in said nut from communication with said valve port.

12. A valve as set forth in claim 11 wherein said chamber, said nut, and said spring means are so structured relative to one another that with said nut threaded into said chamber a maximum distance, the adja-cent coils of said compression coil spring means remain spaced from one another thereby to permit said relief valve member to resiliently move from its closed posi-tion and to thus permit pressure to be relieved from said passage.