Pinch valve sleeve

Abstract

The invention provides a pinch valve sleeve for use within a pinch valve and comprising a flexible-walled, tubular sleeve body having a first end and a second end and an axial flow axis defined by a longitudinally directed bore extending through the sleeve body, wherein the bore has a circular cross section over the axial flow axis at the first and second ends; and a pinch area intermediate the first and second ends wherein the bore at the pinch area has an elliptical cross section over the axial flow axis; wherein the elliptical cross section of the bore at the pinch area has the same or a larger cross-sectional area than the circular cross sections of the bore at the opposite first and second ends.

Description

[0001] PINCH VALVE SLEEVE

[0002] INTRODUCTION

[0003] This invention relates to a pinch valve sleeve for coupling with fluid flow lines, which has a high temperature and pressure operating capacity, and a long service life. More particularly, this invention pertains to a pinch valve sleeve having a flexible-walled sleeve body wherein a pair of transverse bulges are provided to allow the sleeve to be pinched closed without substantial stretching of the sleeve wall.

[0004] BACKGROUND TO THE INVENTION

[0005] A pinch valve sleeve is a hollow tubular, internal, flexible component within a pinch valve that forms a full bore when open and is transversely "pinched" shut by external pressure to stop flow. Pinch valve sleeves are typically used in industries that handle abrasive, corrosive, sanitary, or sensitive media, such as mining, chemical processing, wastewater, food and beverage, and pharmaceutical sectors, to control the flow of liquids, solids, and slurries. Their primary advantage is that the only part of the valve that contacts the fluid is the flexible sleeve, which prevents contamination and clogging. The sleeve can be made from various materials like rubber, urethane, or specialized elastomers, depending on an application's needs for abrasion resistance, chemical compatibility, and temperature tolerance. Pinching or clamping can be done

[0006] APPLICANT: JOHANNES JACOBUS NAUDE via mechanical means or via externally actuated fluid or gas acting from within a chamber around the sleeve to pinch or collapse the sleeve to stop flow.

[0007] Pinch valves are often used in flow lines that handle abrasive impurities like sand, slag or the like, which erode the sleeves and are detrimental to the lifespan of the sleeves. During the pinching or clamping process, the shape of the sleeve is changed radically with varying levels of strain in different parts of the sleeve. Many known pinch valves simply employ a constant cross section, constant wall thickness, flexible tube through which the fluent medium passes. Repeated cyclic strain and bending and stretching of the sleeve material during pinching result in failure of the sleeves over time and is a major determining factor in the lifespan of the sleeves. More particularly, closing of such valves by pinching the sleeve between a seat and a piston or anvil leads to regions of high cracking stress being created at opposite sides of the sleeve and in the bore thereof, at the two folds which occur when such sleeves are pinched closed. These regions of high cracking stress not only reduce the service life of conventional sleeves, but also if such cracks do appear in the bore of such sleeves, they become traps for bacteria, which is totally unacceptable in applications where the sleeves must operate under aseptic conditions (such as the food and beverage, and pharmaceutical sectors).

[0008] Minimizing induced strain in a pinch valve sleeve during the pinching process is accordingly one of the primary objectives of sleeve design. Typical pinch valve sleeves may employ cross-ply reinforcing strips covered by rubber or other elastic material, as set out in prior art examples EP0175028A1 and US4132382A. Minimizing

[0009] APPLICANT: JOHANNES JACOBUS NAUDE strain in the elastic material around the reinforced strips is thus an important factor towards increasing sleeve life.

[0010] The following prior art patent specifications include modified sleeve shapes: EP0574128A2; US5207409A; EP1035360B1 ; GB1058273A; US4044990A;

[0011] W02006106485A2; W003069199A1 ; US3826461A; GB1388295A. In addition, prior art W00065263A1 includes a wear sensor embedded within the sleeve.

[0012] It is an object of the present invention to provide a sleeve for a pinch valve which can be flexed repeatedly and will withstand such flexing better than sleeves conventionally used in such valves, while also making it compatible with existing pinch sleeve housings to be a retrofit to existing systems. A further object of the invention is to provide a pinch valve sleeve that will withstand high internal pressures, without the flexible tube being ruptured, and that will be stressed only by a small amount in being flexed between the pinched and unpinched positions.

[0013] SUMMARY OF THE INVENTION

[0014] According to the invention there is provided a pinch valve sleeve suitable for use within a pinch valve, the sleeve comprising - a flexible-walled, tubular sleeve body having an axial flow axis defined by a longitudinally directed bore extending through the sleeve body, the sleeve body comprising a first end and an axially spaced opposite second end wherein the bore has a circular cross section over the axial flow axis at the first and second ends; and

[0015] APPLICANT: JOHANNES JACOBUS NAUDE a pinch area defined in the sleeve body intermediate the first and second ends wherein the bore at the pinch area has an elliptical cross section over the axial flow axis; wherein the elliptical cross section of the bore at the pinch area has the same or a larger cross-sectional area than the circular cross sections of the bore at the opposite first and second ends.

[0016] The sleeve body may comprise an interior wall and an exterior wall, and may terminate at one end thereof in a radially outwardly extending first flange of flange width W1 circumferentially bordering the first end of the sleeve body, and may terminate at an opposite end thereof in a radially outwardly extending second flange of flange width W1 circumferentially bordering the second end of the sleeve body, and wherein the bore has a circular cross section over the axial flow axis at the first and second ends formed by the interior wall of the sleeve body. The exterior wall of the sleeve body may also have a circular cross section over the axial flow axis at the first and second ends such that the exterior wall is complimentarily configured to the interior wall to define a constant wall thickness T. The sleeve body may include a constant circular bore radius R1 at the first and second ends such that the area of the circular cross section over the axial flow axis is defined as A1 = IT X R12at the first and second ends of the sleeve body.

[0017] The elliptical cross section bore at the pinch area may be defined in an interior wall of the sleeve body and may comprise a semi-major axis (i.e. , the longest radius) R2, and a semi-minor axis (i.e., the shortest radius) R3, wherein the area of the elliptical cross section over the axial flow axis is defined as A2 = IT x R2 x R3, and wherein A2 > A1 .

[0018] APPLICANT: JOHANNES JACOBUS NAUDE The exterior wall of the sleeve body at the pinch area may also have an elliptical cross section over the axial flow axis such that the exterior wall is complimentarily configured to the interior wall to define a constant wall thickness T which is the same as wall thickness T at the first and second ends. The elliptical bore may be characterised therein that R2 > R1 and R3 < R1.

[0019] The pinch area may include two opposing, substantially planar and parallel pinch location areas; and two opposing and radially outwardly projecting shoulder formations formed in the flexible sleeve body and transversely extending from opposite longitudinal ends of the pinch location areas such that the shoulder formations are 90° offset from the pinch location areas and 180° spaced from each other, and such that R3 of the elliptical bore extend to the pinch location areas while R2 of the elliptical bore extend into the shoulder formations. The shoulder formations may have an external transverse sleeve width W2 wherein W2 = W1 of the first and second flanges.

[0020] The pinch area may axially be bordered by two sets of axially spaced bulges formed in the flexible sleeve body at opposing sides of the pinch area, substantially parallel to the pinch location areas and 90° offset relative to the shoulder formations, with the first set of bulges being defined between the pinch area and the first end of the sleeve body, and the second set of bulges being defined between the pinch area and the second end of the sleeve body, such that the pinch area and associated shoulder formations are axially arranged intermediate the first set and the second set of bulges.

[0021] Each set of bulges may comprise two transverse bulges projecting radially outwardly from opposite sides of the sleeve body to define a bore between the bulges that has

[0022] APPLICANT: JOHANNES JACOBUS NAUDE an elliptical cross section over the axial flow axis, wherein the elliptical bore between the bulges is 90° offset to the elliptical bore of the pinch area. The elliptical bore between the bulges may be defined by an interior wall of the sleeve body and may comprise a semi-major axis (i.e., the longest radius) R4, and a semi-minor axis (i.e., the shortest radius) R5, wherein the surface of the elliptical cross section over the axial flow axis at the bulges is defined as A3 = IT x R4 x R5, and wherein A3 > A1 and A3 > A2. The exterior wall of the sleeve body at the bulges may also have an elliptical cross section over the axial flow axis such that the exterior wall is complimentarily configured to the interior wall to define a constant wall thickness T which is the same as wall thickness T at the first and second ends. The elliptical bore may be characterised therein that R4 > R1 and R5 > R1 . The bulges may have an external transverse width W3 wherein W3 < W1 of the first and second flanges. More particularly, the bulges may define a pre-operational displacement H relative to R3 such that (R3 + T + H) > (R1 + T), but (R3 + T + H) < (R1 + T + W1 ). During operation of the pinch valve sleeve, when a pinching action is performed on the pinch location areas to close the elliptical bore, the radial bulges are circumferentially deformed about the axial flow axis to absorb radial strain in the sleeve body, while R3 is reduced to 0 and R2 increases proportionally to the decrease in R3, and specifically such that the bulges radially extend past R3 by a maximum displacement H at the pinch location areas. In the closed sleeve W3 may be zero.

[0023] According to a second aspect of the invention there is provided a pinch valve sleeve suitable for use within a pinch valve, the sleeve comprising - a flexible-walled, tubular sleeve body having an axial flow axis defined by a longitudinally directed bore extending through the sleeve body, the sleeve body

[0024] APPLICANT: JOHANNES JACOBUS NAUDE comprising a first end and an axially spaced opposite second end wherein the bore has a circular cross section over the axial flow axis at the first and second ends; and a pinch area defined in the sleeve body intermediate the first and second ends wherein the bore at the pinch area has an elliptical cross section over the axial flow axis; wherein the pinch area includes two opposing, substantially parallel pinch location areas; and two opposing and radially outwardly projecting shoulder formations formed in the flexible sleeve body and transversely extending from opposite longitudinal ends of the pinch location areas such that the shoulder formations are 90° offset from the pinch location areas and 180° spaced from each other.

[0025] The sleeve body may terminate at one end thereof in a radially outwardly extending first flange of flange width W1 circumferentially bordering the first end of the sleeve body and may terminate at an opposite end thereof in a radially outwardly extending second flange of flange width W1 circumferentially bordering the second end of the sleeve body. The shoulder formations may have an external transverse sleeve width W2 wherein W2 = W1 of the first and second flanges.

[0026] The pinch area may axially be bordered by two sets of axially spaced bulges formed in the flexible sleeve body at opposing sides of the pinch area, substantially parallel to the pinch location areas and 90° offset relative to the shoulder formations, with the first set of bulges being defined between the pinch area and the first end of the sleeve body, and the second set of bulges being defined between the pinch area and the second end of the sleeve body, such that the pinch area and associated shoulder formations are axially arranged intermediate the first set and the second set of bulges.

[0027] APPLICANT: JOHANNES JACOBUS NAUDE Each set of bulges may comprise two transverse bulges projecting radially outwardly from opposite sides of the sleeve body. The bulges may have an external transverse width W3 wherein W3 < W1 of the first and second flanges.

[0028] According to a third aspect of the invention there is provided a pinch valve sleeve suitable for use within a pinch valve, the sleeve comprising - a flexible-walled, tubular sleeve body having an axial flow axis defined by a longitudinally directed bore extending through the sleeve body, the sleeve body comprising a first end and an axially spaced opposite second end wherein the bore has a circular cross section over the axial flow axis at the first and second ends; and a pinch area defined in the sleeve body intermediate the first and second ends wherein the bore at the pinch area has an elliptical cross section over the axial flow axis; wherein the pinch area is axially bordered by two sets of axially spaced bulges formed in the flexible sleeve body at opposite sides of the pinch area, with each set of bulges comprising two transverse bulges projecting radially outwardly from opposite sides of the sleeve body.

[0029] The elliptical cross section bore at the pinch area may comprise a semi-major axis (i.e., the longest radius) R2, and a semi-minor axis (i.e., the shortest radius) R3, wherein the area of the elliptical cross section over the axial flow axis is defined as A2 = IT x R2 x R3. The first set of bulges may be defined between the pinch area and the first end of the sleeve body, and the second set of bulges may be defined between the pinch area and the second end of the sleeve body, such that the pinch area is axially arranged intermediate the first set and the second set of bulges.

[0030] APPLICANT: JOHANNES JACOBUS NAUDE Each set of bulges may comprise two transverse bulges projecting radially outwardly from opposite sides of the sleeve body to define a bore between the bulges that has an elliptical cross section over the axial flow axis, wherein the elliptical bore between the bulges is 90° offset to the elliptical bore of the pinch area. The elliptical bore between the bulges may be defined by an interior wall of the sleeve body and may comprise a semi-major axis (i.e., the longest radius) R4, and a semi-minor axis (i.e., the shortest radius) R5, wherein the surface of the elliptical cross section over the axial flow axis at the bulges is defined as A3 = IT x R4 x R5, and wherein A3 > A1 and A3 > A2. The exterior wall of the sleeve body at the bulges may also have an elliptical cross section over the axial flow axis such that the exterior wall is complimentarily configured to the interior wall to define a constant wall thickness T which is the same as wall thickness T at the first and second ends. The elliptical bore may be characterised therein that R4 > R1 and R5 > R1 .

[0031] The bulges may have an external transverse width W3 wherein W3 < W1 of the first and second flanges. More particularly, the bulges may define a pre-operational displacement H relative to R3 such that (R3 + T + H) > (R1 + T), but (R3 + T + H) < (R1 + T + W1 ). During operation of the pinch valve sleeve, when a pinching action is performed on the pinch location areas to close the elliptical bore, the radial bulges are circumferentially deformed about the axial flow axis to absorb radial strain in the sleeve body, while R3 is reduced to 0 and R2 increases proportionally to the decrease in R3.

[0032] APPLICANT: JOHANNES JACOBUS NAUDE BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Without wishing to be bound thereto, the invention will now further be described and exemplified with reference to the accompanying drawings in which -

[0034] FIGURE 1 is a perspective view of a pinch valve sleeve according to the invention at a first angle of rotation;

[0035] FIGURE 2 is a perspective view of the pinch valve sleeve of Figure 1 , rotated through 90°;

[0036] FIGURE 3 is a sectional view through C-C of the pinch valve sleeve of Figure 1 , sectioned on its longitudinal flow axis X-X, as illustrated in Figure 4;

[0037] FIGURE 4 is an end view of the pinch valve sleeve looking down the longitudinal flow axis;

[0038] FIGURE 5 is a sectional view through D-D of the pinch valve sleeve of Figure 2, rotated through 90° compared to Figures 3 and 4, sectioned on its longitudinal flow axis X-X, as illustrated in Figure 6;

[0039] FIGURE 6 is an end view of the pinch valve sleeve looking down the longitudinal flow axis and rotated through 90° compared to Figure 4;

[0040] FIGURE 7 is sectional view through E-E of the pinch valve sleeve of Figure 1 , sectioned transversely to its longitudinal flow axis X-X, as illustrated in Figure 8;

[0041] FIGURE 8 is a side view of the pinch valve sleeve of Figure 2;

[0042] FIGURE 9 is sectional view through F-F of the pinch valve sleeve of Figure 1 , sectioned transversely to its longitudinal flow axis X-X, as illustrated in Figure 10;

[0043] APPLICANT: JOHANNES JACOBUS NAUDE FIGURE 10 is a side view of the pinch valve sleeve of Figure 2;

[0044] FIGURE 11 is a perspective view of the pinch valve sleeve of Figures 1 and 2 in an open (un-pinched) condition;

[0045] FIGURE 12 is a perspective view of the pinch valve sleeve of Figure 11 in a closed (pinched) condition; and

[0046] FIGURES 13(a)-(c) are photographic side elevations of the pinch valve sleeve according to Figures 1 - 12, with Figure 13(b) rotated through 45° relative to Figure 13(a), and with Figure 13(c) rotated through 90° relative to Figure 13(a).

[0047] SPECIFIC EMBODIMENT OF THE INVENTION

[0048] Unless otherwise defined, all the technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. The term “pinch valve sleeve” should be interpreted to include its synonyms used in the industry, including rubber sleeve, pinch valve liner, hose, tube, rubber membrane, bladder, pinch tube, air sleeve, wetted part, and flexible rubber sleeve, where these terms all refer to a flexible, internal component of a pinch valve that is compressed to control flow. The terms “first,” “second,” etc., which are used in the present application for disclosure, are not intended to indicate any sequence, amount or importance, but only distinguish various components. Also, the terms such as “a,” “an,” etc., are not intended to limit the amount, but indicate the existence of at least one. The terms “comprise,” “comprising,” “include,” “including,” etc., are intended to specify that the elements or the objects stated before these terms encompass the elements or the objects and equivalents thereof listed after these

[0049] APPLICANT: JOHANNES JACOBUS NAUDE terms, but do not preclude the other elements or objects. The phrases “connect”, “connected”, “connecting”, etc., are not intended only to define a physical connection or mechanical connection, but may include an electrical connection, directly or indirectly. “On,” “under,” “right,” “left”, “atop”, and the like are only used to indicate relative position relationship, and when the position of the object which is described is changed, the relative position relationship may be changed accordingly.

[0050] A pinch valve sleeve according to the invention is generally designated by reference numeral (10) and comprises a flexible-walled, tubular sleeve body (12) having an axial flow axis (X-X) defined by a longitudinally directed bore (14) extending through the sleeve body (12). The sleeve body (12) comprises a first end (16) and an opposite, axially spaced second end (18) wherein the bore (14) has a circular cross section over the axial flow axis (X-X) at the first and second ends (16; 18).

[0051] The sleeve body (12) further comprises a pinch area (20) defined in the sleeve body (12) intermediate the first and second ends (16; 18) wherein the bore (14) at the pinch area (20) has an elliptical cross section over the axial flow axis (X-X) to define an elliptical bore (14.1 ) (refer Figure 7); and wherein the elliptical cross section at the pinch area (20) has the same or larger cross sectional area than the circular cross sections at the opposite ends (16; 18).

[0052] The sleeve body (12) comprises an interior wall (12.1 ) and an exterior wall (12.2), and terminates at one end thereof in a radially outwardly extending first flange (22) of flange width W1 circumferentially bordering the first end (16) of the sleeve body (12), and terminates at an opposite end thereof in a radially outwardly extending second

[0053] APPLICANT: JOHANNES JACOBUS NAUDE flange (24) of flange width W1 circumferentially bordering the second end (18) of the sleeve body (12), and wherein the bore (14) has a circular cross section over the axial flow axis (X-X) at the first and second ends (16; 18) formed by the interior wall (12.1 ) of the sleeve body (12). In an assembled pinch valve (not shown) the first and second flanges (22; 24) are axially clamped in a pinch valve housing (not shown) to secure and connect the pinch valve sleeve (10) within the pinch valve, as is common practice in commercial pinch valve design.

[0054] The exterior wall (12.2) of the sleeve body (12) also has a circular cross section over the axial flow axis (X-X) at the first and second ends (18) such that the exterior wall (12.2) is complimentarily configured to the interior wall (12.1 ) to define a constant wall thickness T. The sleeve body (12) includes a constant circular bore radius R1 at the first and second ends (18) such that the area of the circular cross section over the axial flow axis (X-X) is defined as A1 = IT X R12at the first and second ends (16; 18) of the sleeve body (12).

[0055] The elliptical cross section bore (14.1 ) at the pinch area (20) is defined by the interior wall (12.1 ) of the sleeve body (12) and comprises a semi-major axis (i.e., the longest radius) R2, and a semi-minor axis (i.e., the shortest radius) R3, wherein the area of the elliptical cross section over the axial flow axis (X-X) is defined as A2 = IT x R3 x R2, and wherein A2 > A1 . The exterior wall (12.2) of the sleeve body (12) at the pinch area (20) also has an elliptical cross section over the axial flow axis (X-X) such that the exterior wall (12.2) is complimentarily configured to the interior wall (12.1 ) to define a constant wall thickness T which is the same as wall thickness T at the first and

[0056] APPLICANT: JOHANNES JACOBUS NAUDE second ends (16; 18). The elliptical bore (14.1 ) is characterised therein that R2 > R1 , R3 < R2, and R3 < R1.

[0057] The pinch area (20) includes two opposing, substantially planar pinch location areas (21 ); and two opposing and radially outwardly projecting shoulder formations (26) formed in the flexible sleeve body and transversely extending from opposite longitudinal ends of the pinch location areas (21 ) such that the shoulder formations (26) are 90° offset from the pinch location areas (21 ) and 180° spaced from each other, and such that R3 of the elliptical bore (14.1 ) extend to the pinch location areas (21 ), while R2 of the elliptical bore (14.1 ) extend into the shoulder formations (26). The shoulder formations (26) have an external transverse width W2 wherein W2 = W1 of the first and second flanges (22; 24), such that at its broadest transverse width, the shoulder formations substantially align with the circumference of the flanges (22; 24).

[0058] The pinch area (20) is axially bordered by two sets of axially spaced bulges (28) formed in the flexible sleeve body at opposite sides of the pinch area (20), arranged substantially parallel to the planar pinch location areas (21 ), and 90° offset relative to the shoulder formations (26), with the first set of bulges (28) being defined between the pinch area (20) and the first end (16) of the sleeve body (12), and the second set of bulges (28) being defined between the pinch area (20) and the second end (18) of the sleeve body (12). The pinch location areas (21 ) and associated shoulder formations (26) are axially arranged intermediate the first set and the second set of bulges (28).

[0059] APPLICANT: JOHANNES JACOBUS NAUDE Each set of bulges (28) comprises two transverse bulges (28) projecting radially outwardly from opposite sides of the sleeve body (12) to define a bore (14) between the bulges (28) that has an elliptical cross section over the axial flow axis (X-X), wherein the elliptical bore (14) between the bulges (28) is 90° offset to the elliptical bore (14.1 ) of the pinch area (20). The elliptical bore (14) between the bulges (28) is defined by an interior wall (12.1 ) of the sleeve body (12) and comprises a semi-major axis (i.e. , the longest radius) R4, and a semi-minor axis (i.e., the shortest radius) R5, wherein the area of the elliptical cross section over the axial flow axis (X-X) at the bulges (28) is defined as A3 = IT x R4 x R5, and wherein A3 > A1 and A3 > A2. The exterior wall (12.2) of the sleeve body (12) at the bulges (28) also has an elliptical cross section over the axial flow axis (X-X) such that the exterior wall (12.2) is complimentarily configured to the interior wall (12.1 ) to define a constant wall thickness T which is the same as wall thickness T at the first and second ends (18). The elliptical bore (14) is characterised therein that R4 > R1 and R5 > R1. The bulges (28) have an external transverse width W3 wherein W3 < W1 of the first and second flanges (22; 24) such that at its broadest transverse width, the bulges are narrower than the circumference of the flanges (22; 24).

[0060] During operation of pinch valve sleeve (10), a pinching action is performed on the pinch location areas (21 ) in the direction and location of opposing arrows (30) to push together the narrow part of internal bore (14.1 ) to close the pinch valve sleeve (10), as can be seen in Figure 7. The pinch location areas (21 ) coincide with smaller radius R3, and the shoulder formations (26) coincide with the larger radius R2. The radial bulges (28) are circumferentially deformed about the axial flow axis (X-X) such that

[0061] APPLICANT: JOHANNES JACOBUS NAUDE the bulges (28) radially extend past R3 by a maximum displacement H at the pinch location areas (21 ).

[0062] When the pinch valve sleeve (10) in the open position (as illustrated in Figures 7 and 11 ) is closed, a typical mechanical force is applied in the direction of arrows (30) and R3 will start to decrease. As R3 decreases and minimal strain in the pinch valve sleeve (10) is assumed, radial bulges (28) will be flattened to account for the decrease in R3 displacement.

[0063] The values of all parameters in the pinch valve sleeve (10) may be such that when the pinch valve sleeve (10) is closed (R3=0) the radial bulges (28) are also flattened substantially while R2 have increased. The values of all parameters in the pinch valve sleeve (10) may also be such that during operation of the pinch valve sleeve (10), when a pinching action is performed on the pinch location areas (21 ) to close the elliptical bore (14.1 ), the radial bulges (28) are circumferentially deformed about the axial flow axis (X-X) to absorb radial strain within the sleeve body (12), while R3 is reduced to 0 and R2 increases proportionally to the decrease in R3 and specifically such that the bulges (28) may radially extend past R3 by a maximum displacement H at the pinch location areas (21 ). In the closed pinch valve sleeve (10), W3 may be zero.

[0064] Due to the elliptical cross section over the axial flow axis (X-X) of elliptical bore (14.1 ) strain in this area is less than the strain in closing / flattening a circular structure. It is to be appreciated that all parameters of the pinch valve sleeve (10) may be optimized / sized to result in minimal strain when the pinch valve sleeve (10) is closed.

[0065] APPLICANT: JOHANNES JACOBUS NAUDE The pinch valve sleeve (10) of the invention may include a wear sensor (not shown) and may be actuated mechanically, or by means of fluid or gas acting from within a chamber around the pinch valve sleeve (10) to pinch or collapse the sleeve to stop flow. It will be appreciated that the present design permits maintaining, or lowering, flow speed of fluent medium through the sleeve (10) despite a change in the cross- sectional dimensions over the axial flow axis (X-X) of the internal bore (14).

[0066] Tags or loops may be included on an outside of pinch valve sleeve (10) to hook around a mechanical pinching mechanism to enable the mechanical pinching mechanism to both pinch the pinch valve sleeve (10) when closing, as well as pull the pinch valve sleeve (10) open, for example in cases where the pinch valve sleeve (10) is subject to a vacuum within the pipe line in which it is installed.

[0067] The pinch valve sleeve (10) may be manufactured by alternately layering different materials to form the sleeve body (12), which may include layering internal reinforcing material between the layers. It is conceivable that the interior wall (12.1 ) may be of a different kind of material than the exterior wall (12.2) of the sleeve body (12) (for example a different type of rubber) with reinforcing material sandwiched in between.

[0068] It is common practice in pinch valve sleeve practice to separate fluid being transported (e.g., in the event of a fluid type change) by a plug that fits snugly in the pipeline and that travels with the flow in the pipeline. It is to be appreciated that such a plug, with a typical radius R1 will pass through the pinch valve sleeve (10) by simply deforming the internal elliptical bore (14.1 ) to a circular bore as the plug is passed through the bore.

[0069] APPLICANT: JOHANNES JACOBUS NAUDE The pinch valve sleeve (10) is further characterized therein that under conditions of extreme internal fluid pressure, when the mechanical pinching mechanism that acts on the pinch location areas (21 ) is released, the internal elliptical bore (14.1 ) may deform to a substantially circular bore such that the circular cross section over the axial flow axis (X-X) at the pinch area (20) is larger than A3. More specifically, the internal elliptical bore (14.1 ) at the pinch area (20) and the bore (14) at the bulges (28) may jointly deform to a maximum deformation where the entire axial bore (14) of the sleeve body (12) is temporarily deformed into a substantially cylindrical bore (14) with a circular cross section over the axial flow axis (X-X) which is > A1 .

[0070] It will be appreciated that alternative embodiments of the invention would be possible without departing from the spirit and scope of the invention as set out in the claims. So, for example, it will be appreciated that the wall thickness (T) of the sleeve body (12) may vary along its bore (14). In one embodiment of the invention the pinch valve sleeve (10) may include a thicker wall thickness (T+) approximate either one, or both of, the first and second ends (16; 18) of the sleeve body (12) which may reduce R1 so that the bore (14) at either one, or both of, the first and second ends (16; 18) act as a flow restrictor, as is required in some commercial applications.

[0071] APPLICANT: JOHANNES JACOBUS NAUDE

Claims

CLAIMS1. A pinch valve sleeve (10) suitable for use within a pinch valve, the sleeve comprising- a flexible-walled, tubular sleeve body (12) having an axial flow axis (X-X) defined by a longitudinally directed bore (14) extending through the sleeve body (12), the sleeve body (12) comprising a first end (16) and an axially spaced opposite second end (18) wherein the bore (14) has a circular cross section over the axial flow axis (X-X) at the first and second ends (16; 18); and a pinch area (20) defined in the sleeve body (12) intermediate the first and second ends (16; 18) wherein the bore (14) at the pinch area (20) has an elliptical cross section over the axial flow axis (X-X); wherein the elliptical cross section of the bore (14.1 ) at the pinch area (20) has the same or a larger cross-sectional area than the circular cross sections of the bore (14) at the opposite first and second ends (16; 18).

2. The pinch valve sleeve (10) according to claim 1 wherein the sleeve body (12) comprises an interior wall (12.1 ) and an exterior wall (12.2), and terminates at one end thereof in a radially outwardly extending first flange (22) of flange width W1 circumferentially bordering the first end (16) of the sleeve body (12), and terminates at an opposite end thereof in a radially outwardly extending second flange (24) of flange width W1 circumferentially bordering the second end (18) of the sleeve body (12), and wherein the bore (14) has a circular cross section over the axial flow axis (X-X) with a constant circular bore (14) radius R1 at the first and second ends (16; 18) formed by the interior wall (12.1 ) of the sleeve bodyAPPLICANT: JOHANNES JACOBUS NAUDE(12) such that the area of the circular cross section over the axial flow axis (X-X) is defined as A1 = IT X R12at the first and second ends (16; 18) of the sleeve body (12).

3. The pinch valve sleeve (10) according to claim 2 wherein the exterior wall (12.2) of the sleeve body (12) also has a circular cross section over the axial flow axis (X-X) at the first and second ends (16; 18) such that the exterior wall (12.2) is complimentarily configured to the interior wall (12.1 ) to define a constant wall thickness T.

4. The pinch valve sleeve (10) according to claim 3 wherein the elliptical cross section bore (14.1 ) at the pinch area (20) is defined by an interior wall (12.1 ) of the sleeve body (12) and comprises a semi-major axis (i.e., the longest radius) R2, and a semi-minor axis (i.e., the shortest radius) R3, wherein the area of the elliptical cross section over the axial flow axis (X-X) is defined as A2 = IT x R3 x R2, and wherein A2 > A1 .

5. The pinch valve sleeve (10) according to claim 4 wherein the elliptical bore (14.1 ) is characterised therein that R2 > R1 and R3 < R1.

6. The pinch valve sleeve (10) according to claim 5 wherein the exterior wall (12.2) of the sleeve body (12) at the pinch area (20) also has an elliptical cross section over the axial flow axis (X-X) such that the exterior wall (12.2) is complimentarily configured to the interior wall (12.1 ) to define a constant wall thickness T which is the same as wall thickness T at the first and second ends (16; 18).APPLICANT: JOHANNES JACOBUS NAUDE7. The pinch valve sleeve (10) according to claim 6 wherein the pinch area (20) includes two opposing, substantially planar and parallel pinch location areas (21 ); and two opposing and radially outwardly projecting shoulder formations (26) formed in the flexible sleeve body (12) and transversely extending from opposite longitudinal ends of the pinch location areas (21 ) such that the shoulder formations (26) are 90° offset from the pinch location areas (21 ) and 180° spaced from each other, and such that R3 of the elliptical bore (14.1 ) extends to the pinch location areas (21 ) while R2 of the elliptical bore (14.1 ) extends into the shoulder formations (26).

8. The pinch valve sleeve (10) according to claim 7 wherein the shoulder formations (26) have an external transverse width W2 wherein W2 = W1 of the first and second flanges (22; 24), such that at its broadest transverse width, the shoulder formations substantially align with the circumference of the flanges (22; 24).

9. The pinch valve sleeve (10) according to claim 8 wherein the pinch area (20) is axially bordered by two sets of axially spaced bulges (28) formed in the flexible sleeve body (12) at opposing sides of the pinch area (20) and 90° offset relative to the shoulder formations (26), with the first set of bulges (28) being defined between the pinch area (20) and the first end (16) of the sleeve body (12), and the second set of bulges (28) being defined between the pinch area (20) and the second end (18) of the sleeve body (12), such that the pinch area (20) and associated shoulder formations (26) are axially arranged intermediate the first set and the second set of bulges (28).APPLICANT: JOHANNES JACOBUS NAUDE10. The pinch valve sleeve (10) according to claim 9 wherein each set of bulges (28) comprises two transverse bulges (28) projecting radially outwardly from opposite sides of the sleeve body (12) to define a bore (14) between the bulges (28) that has an elliptical cross section over the axial flow axis (X-X), wherein the elliptical bore (14) between the bulges (28) is 90° offset to the elliptical bore (14.1 ) of the pinch area (20).11 . The pinch valve sleeve (10) according to claim 10 wherein the elliptical bore (14) between the bulges (28) is defined by an interior wall (12.1 ) of the sleeve body (12) and comprises a semi-major axis (i.e., the longest radius) R4, and a semiminor axis (i.e., the shortest radius) R5, wherein the surface of the elliptical cross section over the axial flow axis (X-X) at the bulges (28) is defined as A3 = IT x R4 x R5, and wherein A3 > A1 and A3 > A2.

12. The pinch valve sleeve (10) according to claim 11 wherein the elliptical bore (14) is characterised therein that R4 > R1 and R5 > R1 .

13. The pinch valve sleeve (10) according to claim 12 wherein the exterior wall (12.2) of the sleeve body (12) at the bulges (28) also has an elliptical cross section over the axial flow axis (X-X) such that the exterior wall (12.2) is complimentarily configured to the interior wall (12.1 ) to define a constant wall thickness T which is the same as wall thickness T at the first and second ends (16; 18).APPLICANT: JOHANNES JACOBUS NAUDE14. The pinch valve sleeve (10) according to claim 13 wherein the bulges (28) have an external transverse width W3 wherein W3 < W1 of the first and second flanges (22; 24) such that at its broadest transverse width, the bulges are narrower than the circumference of the flanges (22; 24).

15. The pinch valve sleeve (10) according to claim 14 wherein the bulges (28) define a pre-operational displacement H relative to R3 such that (R3 + T + H) > (R1 + T), but (R3 + T + H) < (R1 + T + W1 ).

16. The pinch valve sleeve (10) according to claim 15 wherein during operation of the pinch valve sleeve (10), when a pinching action is performed on the pinch location areas (21 ) to close the elliptical bore (14.1 ), the radial bulges (28) are circumferentially deformed about the axial flow axis (X-X) to absorb radial strain within the sleeve body (12), while R3 is reduced to 0 and R2 increases proportionally to the decrease in R3, and specifically such that the bulges (28) radially extend past R3 by a maximum displacement H at the pinch location areas (21 ).

17. A pinch valve sleeve (10) suitable for use within a pinch valve, the sleeve comprising- a flexible-walled, tubular sleeve body (12) having an axial flow axis (X-X) defined by a longitudinally directed bore (14) extending through the sleeve body (12), the sleeve body (12) comprising a first end (16) and an axially spaced opposite second end (18) wherein the bore (14) has a circular cross section over the axial flow axis (X-X) at the first and second ends (16; 18); andAPPLICANT: JOHANNES JACOBUS NAUDEa pinch area (20) defined in the sleeve body (12) intermediate the first and second ends (16; 18) wherein the bore (14.1 ) at the pinch area (20) has an elliptical cross section over the axial flow axis (X-X); wherein the pinch area (20) includes two opposing, substantially parallel pinch location areas (21 ); and two opposing and radially outwardly projecting shoulder formations (26) formed in the flexible sleeve body (12) and transversely extending from opposite longitudinal ends of the pinch location areas (21 ) such that the shoulder formations (26) are 90° offset from the pinch location areas (21 ) and 180° spaced from each other.

18. The pinch valve sleeve (10) according to claim 17 wherein the sleeve body (12) terminates at one end thereof in a radially outwardly extending first flange (22) of flange width W1 circumferentially bordering the first end (16) of the sleeve body (12) and terminates at an opposite end thereof in a radially outwardly extending second flange (24) of flange width W1 circumferentially bordering the second end (18) of the sleeve body (12); and wherein the shoulder formations (26) have an external sleeve width W2 wherein W2 = W1 of the first and second flanges (22;24) such that at its broadest transverse width, the shoulder formations substantially align with the circumference of the flanges (22; 24).

19. The pinch valve sleeve (10) according to claim 18 wherein the pinch area (20) is axially bordered by two sets of axially spaced bulges (28) formed in the flexible sleeve body (12) at opposite sides of the pinch area (20) and 90° offset relative to the shoulder formations (26), with the first set of bulges (28) being defined between the pinch area (20) and the first end (16) of the sleeve body (12), andAPPLICANT: JOHANNES JACOBUS NAUDEthe second set of bulges (28) being defined between the pinch area (20) and the second end (18) of the sleeve body (12), such that the pinch area (20) and associated shoulder formations (26) are axially arranged intermediate the first set and the second set of bulges (28).

20. The pinch valve sleeve (10) according to claim 19 wherein each set of bulges (28) comprises two transverse bulges (28) projecting radially outwardly from opposite sides of the sleeve body (12), wherein the bulges (28) have an external width W3 wherein W3 < W1 of the first and second flanges (22; 24) such that at its broadest transverse width, the bulges are narrower than the circumference of the flanges (22; 24).

21. A pinch valve sleeve (10) suitable for use within a pinch valve, the sleeve comprising- a flexible-walled, tubular sleeve body (12) having an axial flow axis (X-X) defined by a longitudinally directed bore (14) extending through the sleeve body (12), the sleeve body (12) comprising a first end (16) and an axially spaced opposite second end (18) wherein the bore (14) has a circular cross section over the axial flow axis (X-X) at the first and second ends (16; 18); and a pinch area (20) defined in the sleeve body (12) intermediate the first and second ends (16; 18) wherein the bore (14) at the pinch area (20) has an elliptical cross section over the axial flow axis (X-X); wherein the pinch area (20) is axially bordered by two sets of axially spaced bulges(28) formed in the flexible sleeve body (12) at opposing sides of the pinch areaAPPLICANT: JOHANNES JACOBUS NAUDE(20), with each set of bulges (28) comprising two transverse bulges (28) projecting radially outwardly from opposite sides of the sleeve body (12).

22. The pinch valve sleeve (10) according to claim 21 wherein the first set of bulges (28) are defined between the pinch area (20) and the first end (16) of the sleeve body (12), and the second set of bulges (28) are defined between the pinch area (20) and the second end (18) of the sleeve body (12), such that the pinch area (20) is axially arranged intermediate the first set and the second set of bulges (28); and wherein each set of bulges (28) comprises two transverse bulges (28) projecting radially outwardly from opposite sides of the sleeve body (12) to define a bore (14) between the bulges (28) that has an elliptical cross section over the axial flow axis (X-X), wherein the elliptical bore (14) between the bulges (28) is 90° offset to the elliptical bore (14.1 ) of the pinch area (20).

23. The pinch valve sleeve (10) according to claim 22 wherein the bore (14) has a circular cross section over the axial flow axis (X-X) with a constant circular bore (14) radius R1 at the first and second ends (16; 18) of the sleeve body (12) such that the area of the circular cross section over the axial flow axis (X-X) is defined as A1 = TT X R12; and wherein the elliptical cross section bore (14.1 ) at the pinch area (20) comprises a semi-major axis (i.e. , the longest radius) R2, and a semiminor axis (i.e., the shortest radius) R3, wherein the area of the elliptical cross section over the axial flow axis (X-X) is defined as A2 = IT x R3 x R2; and the elliptical bore (14) between the bulges (28) comprises a semi-major axis (i.e., the longest radius) R4, and a semi-minor axis (i.e., the shortest radius) R5, whereinAPPLICANT: JOHANNES JACOBUS NAUDEthe area of the elliptical cross section over the axial flow axis (X-X) at the bulges(28) is defined as A3 = IT X R4 X R5, and wherein A3 > A2 and A3 > A1 .

24. The pinch valve sleeve (10) according to claim 23 wherein the elliptical bore (14) between the bulges (28) is characterised therein that R4 > R1 and R5 > R1 .

25. The pinch valve sleeve (10) according to claim 24 wherein the exterior wall (12.2) of the sleeve body (12) at the bulges (28) also has an elliptical cross section over the axial flow axis (X-X) such that the exterior wall (12.2) is complimentarily configured to the interior wall (12.1 ) to define a constant wall thickness T which is the same as wall thickness T at the first and second ends (16; 18).

26. The pinch valve sleeve (10) according to claim 25 wherein the sleeve body (12) terminates at one end thereof in a radially outwardly extending first flange (22) of flange width W1 circumferentially bordering the first end (16) of the sleeve body (12), and terminates at an opposite end thereof in a radially outwardly extending second flange (24) of flange width W1 circumferentially bordering the second end (18) of the sleeve body (12), and wherein the bulges (28) have an external width W3 wherein W3 < W1 of the first and second flanges (22; 24) such that at its broadest transverse width, the bulges are narrower than the circumference of the flanges (22; 24)..

27. The pinch valve sleeve (10) according to claim 26 wherein the bulges (28) define a pre-operational displacement H relative to R3 such that (R3 + T + H) > (R1 + T), but (R3 + T + H) < (R1 + T + W1 ).APPLICANT: JOHANNES JACOBUS NAUDE28. The pinch valve sleeve (10) according to claim 27 wherein during operation of the pinch valve sleeve (10), when a pinching action is performed on the pinch location areas (21 ) to close the elliptical bore (14.1 ), the radial bulges (28) are circumferentially deformed about the axial flow axis (X-X) to absorb radial strain within the sleeve body (12), while R3 is reduced to 0 and R2 increases proportionally to the decrease in R3 and specifically such that the bulges (28) radially extend past R3 by a maximum displacement H at the pinch location areas (21 ).

29. The pinch valve sleeve (10) according to anyone of claims 1 to 28 wherein the pinch valve sleeve (10) includes a thicker wall thickness (T+) approximate either one, or both of, the first and second ends (16; 18) of the sleeve body (12) which reduces R1 so that the bore (14) at either one, or both of, the first and second ends (16; 18) acts as a flow restrictor.

30. The pinch valve sleeve (10) according to anyone of claims 1 to 28 wherein the pinch valve sleeve (10) is characterized therein that under conditions of extreme internal fluid pressure, when the mechanical pinching mechanism that acts on the pinch location areas (21 ) is released, the internal elliptical bore (14.1 ) is deformed to a substantially circular bore such that the circular cross section over the axial flow axis (X-X) at the pinch area (20) is larger than A3.

31. The pinch valve sleeve (10) according to claim 30 wherein the internal elliptical bore (14.1 ) at the pinch area (20) and the bore (14) at the bulges (28) are jointly deformed to a maximum deformation where the entire axial bore (14) of theAPPLICANT: JOHANNES JACOBUS NAUDEsleeve body (12) is temporarily deformed into a substantially cylindrical bore (14) with a circular cross section over the axial flow axis (X-X) which is > A1 .

32. A pinch valve sleeve (10) according to anyone of claims 1 to 31 substantially as herein illustrated and exemplified with reference to the accompanying Figures 1 to 13.APPLICANT: JOHANNES JACOBUS NAUDE

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