Low flow pressure check valve

Abstract

A check valve (106) includes a valve body (200) formed from an elastomeric material, the valve body having an inlet side (210) and an outlet side (212). The valve body includes a rim (202) forming an outer periphery of the valve body, and a hinge section (204) including an annular groove formed on an inlet side of the valve body radially inward of the rim and adjacent the rim. The valve body further includes a plurality of tabs (208) formed at a center of the valve body by one or more slits extending radially outward from the center of the valve body toward the hinge. In the closed position, the hinge section is coplanar with the plurality of tabs.

Description

Cross Reference to Related Applications

[0002] This application claims priority to U.S. Application No. 18 / 140,952, filed April 28, 2023. The disclosure of the prior application is considered part of the disclosure of this application and is incorporated by reference into the disclosure of this application. TECHNICAL FIELD

[0003] The present application relates to dispensing fluids. BACKGROUND

[0004] Fluid dispensing systems can include a fluid source and a valve to control the flow of fluid. For example, a fluid reservoir can be positioned above a valve, in which case the valve can be a check valve and provide check against pressure from the reservoir head. Alternatively, the reservoir can be positioned below the valve and the valve provides check against negative pressure. A variety of fluids with different thermophysical and transport properties can be dispensed through such systems.

[0005] A variety of valve geometries can be used in such systems, but each has undesirable effects. For example, a duckbill valve does not provide check pressure against forward flow pressure. There is no force acting on the duckbill valve tabs to keep them in face-to-face contact (resulting in the possibility of condensing fluid forming on the outside of the valve tabs). For umbrella and mushroom valves, the output fluid flow is radial with respect to the supply tube, which requires redirecting the fluid flow into the user’s receptacle. Such fluid flow redirecting components downstream of the valve have the potential to cause fluid to reside, resulting in condensation.

[0006] As another example, a cross valve uses a relatively thick disk of elastomeric material and the knife cross cut produces four valve tabs diverging from the axis that flex open under flow pressure. However, in such a valve it is not possible to have both low high flow pressure and high open check pressure. A dome valve is similar to a cross valve but has a central portion that is dome shaped with a cross cut to form the valve tabs. However, the valve does not work well for low viscosity fluids because the inversion of the dome is not always perfectly symmetrical, which causes the fluid jet to be radially ejected from the valve tabs both when the valve is open and when it is closed. Another problem with the dome valve is that if the volume of reverse flow is not precisely controlled, air can be drawn through the valve under the reverse flow condition when the valve is closed. This is generally undesirable because the entry of air through the valve can cause air-borne bacterial contamination and / or oxidation of the fluid.

[0007] There is a need for a valve for fluid dispensing systems that has improved flow characteristics. SUMMARY

[0008] The present disclosure describes systems and methods for dispensing fluids.

[0009] In one aspect, a check valve includes a valve body formed of an elastomeric material, the valve body having an inlet side and an outlet side, and including a rim forming an outer periphery of the valve body; a hinge section including an annular groove formed on the inlet side of the valve body radially inward of and adjacent to the rim; and a plurality of tabs formed at a center of the valve body by one or more slits extending radially outward from the center of the valve body toward the hinge, and the hinge section is coplanar with the plurality of tabs when in a closed position.

[0010] In one aspect, a dispensing system includes a reservoir; a pump including an inlet fluidly coupled to the reservoir and an outlet; a valve fluidly coupled to the outlet of the pump, the valve including: a valve body formed of an elastomeric material, the valve body having an inlet side and an outlet side, and including a rim forming an outer periphery of the valve body; a hinge section including an annular groove formed on the inlet side of the valve body radially inward of and adjacent to the rim; and a plurality of tabs formed at a center of the valve body by one or more slits extending radially outward from the center of the valve body toward the hinge, and at least from the center to a surface of the hinge is planar on the outlet side of the valve body.

[0011] In one aspect, a method for dispensing a fluid includes opening a valve by providing a fluid pressure to an inlet side of the valve, the fluid pressure being greater than a check pressure of the valve; dispensing the fluid through the valve; and closing the valve by providing a negative pressure to the inlet side of the valve.

[0012] In one aspect, a valve includes a valve body formed of an elastomeric material, the valve body including an inlet side; an outlet side including a planar surface; a rim having a first thickness and forming an outer periphery of the valve body; a hinge section having a second thickness and positioned inward of and adjacent to the rim, the hinge section defining a pivot point arranged closer to the outlet side than to the inlet side; and a plurality of tabs having a third thickness greater than the second thickness, the plurality of tabs formed at a center of the valve body by one or more slits extending radially outward from the center of the valve body toward the hinge section.

[0013] Implementations of the aspects can include one or more of the following features.

[0014] In some applications, a surface extending at least from the center to the hinge and including the hinge is planar on the outlet side of the valve body.

[0015] In some applications, the annular groove comprises a triangle, a square, a pentagon, or a hexagon.

[0016] In some applications, the hinge segment has a thickness that is less than a thickness of the plurality of lipped tabs. In some cases, the annular groove defines a hinge point of the plurality of lipped tabs that is offset from a vertical center of the valve body toward the outlet side of the valve body.

[0017] In some applications, a check pressure of the check valve is determined by an offset distance between the hinge point of the plurality of lipped tabs and a midpoint of the thickness of the plurality of lipped tabs. In some cases, the offset distance is determined by a depth of the annular groove.

[0018] In some applications, these aspects include an annular sealing bead protruding from a rim on an inlet side of the valve body.

[0019] In some applications, these aspects include a closed position in which edges of the plurality of lipped tabs are coplanar with the valve body, thereby preventing fluid communication through the valve, and an open position in which the plurality of lipped tabs are hinged outward from the valve body, thereby allowing fluid communication from the inlet side to the outlet side, and a pressure that maintains the check valve in the open position is less than a check pressure of the check valve.

[0020] In some applications, these aspects further include a ring that defines a central opening in the ring, the ring being connected to an outlet of the pump, wherein the rim of the valve is held between the ring and the outlet of the pump.

[0021] In some applications, the valve provides a check pressure against forward flow that is greater than a hydrostatic pressure from fluid in the reservoir when the reservoir is full.

[0022] In some applications, the pump provides sufficient pressure to open the valve.

[0023] In some applications, these aspects include a closed position in which edges of the plurality of lipped tabs are coplanar with the valve body, thereby preventing fluid communication through the valve, and an open position in which the plurality of lipped tabs are hinged outward from the valve body, thereby allowing fluid communication from the inlet side to the outlet side, and edges of the plurality of lipped tabs on an inlet side of the valve body are compressed when transitioning from the closed position to the open position.

[0024] In some cases, the valve is configured to transition from the open position to the closed position in response to a negative pressure on the inlet side. In some cases, no air is entrained into the reservoir when the valve transitions from the open position to the closed position.

[0025] In some applications, the valve and the pump are integrated with the reservoir as a disposable item.

[0026] In some applications, the reverse check pressure of the valve is determined by an inner diameter of an outlet of the pump.

[0027] In some applications, these aspects further include a backing washer having an inner diameter that is smaller than an inner diameter of an outlet of the pump, the backing washer positioned between the outlet of the pump and the inlet side of the valve body, and the reverse check pressure of the valve determined by the inner diameter of the backing washer.

[0028] In some applications, closing the valve includes providing the negative pressure by reversing a flow direction of the fluid.

[0029] In some applications, dispensing the fluid includes a fluid flow pressure that is less than a check pressure of the valve.

[0030] In some applications, closing the valve does not introduce air through the valve.

[0031] In some applications, closing the valve includes closing the valve symmetrically.

[0032] In some applications, closing the valve includes closing the valve without dripping of the dispensed fluid.

[0033] In some applications, the third thickness increases from the hinge segment to a center of the valve body.

[0034] Particular applications of the subject matter described in this specification can be applied to realize one or more of the following advantages. The check valve can provide high check pressure and low flow pressure at high flow rates. The check valve can close without introducing air into a fluid reservoir, thereby reducing the risk of contaminating the reservoir fluid. The check valve can close in a drip-free manner, preventing buildup on the outlet side of the valve. The check valve can dispense fluids having a wide range of thermophysical and transport properties. The check valve can open and close in a symmetrical manner, preventing misfiring and spraying of the reservoir fluid during opening or closing. The check valve can have different opening and closing check pressures. The thick valve flange lip of the check valve can locally deform around a particle (e.g., a seed or a fiber) and still form a seal when in the closed position.

[0035] Details of one or more applications of the subject matter described in this specification are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figures 1A-1B An example fluid dispensing system is shown.

[0037] Figures 2A-2B An example valve for dispensing fluid is shown in a closed position.

[0038] Figures 3A-3B An example valve for dispensing fluid is shown in an open position.

[0039] Figure 4 A cross-sectional view of an example valve installed in a fluid dispensing system is shown.

[0040] Figures 5A-5B A cross-sectional view of an example valve installed in a fluid dispensing system using an alternative installation configuration is shown.

[0041] Figure 6 An example variation of the valve of Figure 1 including a different profile of the lip is shown.

[0042] Figure 7 An example variation of the valve of Figure 1 including a different annular groove shape is shown.

[0043] Figures 8A-8C An example variation of the valve of Figure 1 including a different annular groove shape is shown.

[0044] Figure 8D An example variation of the valve of Figure 1 including a lip with increased thickness is shown.

[0045] Figure 9 A flowchart of an example method of dispensing fluid using any of the example valves disclosed herein is shown.

[0046] Like reference numbers in the various drawings indicate like elements. DETAILED DESCRIPTION

[0047] Figures 1A-1BAn exemplary system 100 for dispensing a fluid is shown. The system includes a fluid reservoir 102, a pump 104, and a valve 106. The fluid dispensing system can be used to dispense a fluid into individual containers. For example, the fluid dispensing system can be used in a supermarket where consumers can refill smaller fluid product containers (e.g., condiments, beverages, soap, laundry detergent, etc.) from larger bulk containers. The system can be oriented in any direction. For example, the fluid reservoir 102 can be positioned above, below, or to the side of the valve 106. The valve 106 can provide a back pressure that is greater than the hydrostatic pressure of the fluid from the fluid reservoir 102. The pump 104 can be, for example, a rotary pump. In addition, the pump 104 can provide a pressure that is great enough to overcome the back pressure and open the valve 106 to dispense fluid from the reservoir 102, and a vacuum pressure that is great enough to close the valve 106.

[0048] The pump 104 can control the dispensing of the fluid. For example, the pump 104 can dispense a specific volume of fluid. The pump 104 is connected to a motor 108 by a drive shaft 110. The pump 104 has an inlet 112 and an outlet 114. The inlet 112 of the pump can be fluidly coupled to the fluid reservoir 102, for example, by a bag gland 118. The outlet 114 of the pump is fluidly coupled to the valve 106. The valve 106 can be held at the outlet 114 of the pump by a retaining ring 120. The retaining ring 120 includes a circular opening and an annular rim that allows fluid to pass through the valve 106 and be dispensed through the center of the retaining ring 120. The forward direction of fluid flow 122 is from the fluid reservoir to the inlet 112 of the pump 104, from the inlet 112 through the pump 104 to the outlet 114, and from the outlet 114 through the valve 106. In some cases, the pump 104 can pump fluid in the opposite direction, for example, by reversing rotation. In some cases, a pipe, tube, or hose can be used to fluidly couple the pump outlet 114 to the valve 106.

[0049] In some applications, the fluid dispensing system 100 can be provided as a single-use disposable item that includes the reservoir 102, the pump 104, and the valve 106. The fluid dispensing system 100 can include an identifier, such as a bar code, a QR code, or an RFID tag, for example, to identify the type of fluid contained in the reservoir 102. The fluid dispensing system 100 can be inserted into a receptacle that identifies the system based on the identifier and activates preconfigured dispensing parameters based on the identified fluid dispensing system 100.

[0050] In some applications, the fluid dispensing system 100 can be a squeeze bottle, and the valve 106 can be installed in the cap of the squeeze bottle. By installing the valve 106, the squeeze bottle can form a "dropless" container. For example, when the squeeze bottle is squeezed or compressed, the valve 106 can open symmetrically without forming any spray or droplets. When the squeeze bottle is released, a negative pressure is formed on the inlet side of the valve 106, and the valve 106 closes symmetrically without forming a false fluid jet, spray, or droplets. The counter blow pressure of the valve can also prevent air from being drawn into the squeeze bottle when the vacuum pressure applied by the squeeze bottle is lower than the counter blow pressure of the valve.

[0051] Figure 2A A cross-sectional view of an example valve 106 is shown, Figure 2B A plan view of an example valve 106 is shown. The valve 106 includes a valve body 200 defining a rim 202, a hinge section 204, and a center portion 206. A plurality of valve lobes 208 are formed in the center portion 206. The valve body 200 is made of an elastomeric material. Examples of elastomeric materials include silicone rubber, polyurethane, rubber-modified polypropylene, natural rubber, synthetic rubber (such as EPDM). Desired properties are low creep, high elongation, high resilience, inertness to check-valve fluid. The valve body includes an inlet side 210 and an outlet side 212. The outlet side 212 can be planar. The hinge section 204 and the valve lobes 208 can be coplanar when the valve is in a closed position. For example, while the thickness of the valve lobes 208 can extend beyond the plane common to the hinge section 204, in some applications at least a portion of the valve lobes 208 in the radial direction is coplanar with the hinge section 208. However, when the valve 106 is open, as shown, the edge portions of the valve lobes extend beyond the plane containing the hinge section 208. Figure 3A

[0052] In some applications, the outlet side 212 can be slightly concave or slightly convex. The valve body 200 can have a circular shape in plan view. In some applications, the outlet side 212 is planar from the center 214 to the hinge section 204. The rim 220, the hinge section 204, and the center portion 206 have respective thicknesses 216, 228, and 224 measured between the inlet side 210 and the outlet side 212. The thickness 228 of the hinge section 204 is less than the thicknesses 216 and 224 of the rim 220 and the center portion 206. In some examples, as shown, Figure 2A

[0053] ​​The rim 202 forms an outer periphery of the valve body 200. The rim 202 has a thickness 216. The hinge section 204 is radially inward from and adjacent to the rim 202. The hinge section 204 is defined by an annular groove 218. The annular groove 218 forms a pivot point 226 between a bottom of the annular groove 218 and the outlet side 212 of the valve 106 in a thin portion 228 of the valve body 200. The annular groove 218 is formed in the inlet side 210 of the valve body 200 such that there is an offset 220 between a midpoint 222 of the thickness 224 of the central portion 206 and the pivot point 226. The rim is supported by the thin hinge section 204 for the thick central portion 206. The location of the pivot point 226 can be adjusted by adjusting the depth of the annular groove 218.

[0054] The central portion 206 includes a plurality of lobes 208 defined by slits 230 and 232. In this example, the slits 230 and 232 have the same length. The slits 230 and 232 can be formed by, for example, a knife cross cut. The slits 230 and 232 run through the entire valve body 200 from the inlet side 210 to the outlet side 212. In this example, four valve lobes 208 are defined by the slits 230 and 232. The slits 230 and 232 extend radially outward from the center 214 toward the hinge section 204. In various examples, the valve 106 can have more or fewer valve lobes 208.

[0055] The valve body has a closed position and an open position. In the closed position (as shown in FIG. 1), the valve 106 is closed and fluid flow is blocked. In the open position (as shown in FIG. 2), the valve 106 is open and fluid flow is allowed. Figures 2A-2BIn the closed position, the valve tab 208 is aligned in the plane of the valve body 200 and the edges of the valve tab 208 formed at the slits 230 and 232 contact, preventing fluid from passing through the valve. In the open position, the valve tab 208 is bent outward at the hinge segment 204, forming an opening through which fluid can flow. As the valve 106 transitions from the closed position to the open position, the inlet side 210 of the valve tab 208 must compress due to the offset 220 between the midpoint 222 and the pivot point 226. The point of the valve tab 208 travels along the path shown by lines 234 and 236. The distance 238 between lines 234 and 236 represents the amount the valve tab 208 must compress as it transitions from the closed position to the open position. The force required to compress the valve tab 208 determines the check pressure of the valve. The check pressure can be adjusted by adjusting the thickness 224 of the valve tab, by adjusting the diameter of the annular groove 218, by adjusting the depth of the annular groove 218, by adjusting the length of the slits 230 and 232, and / or by adjusting the stiffness of the resilient material of the valve body 200. The valve tab 208 is not compressed in either the open or closed positions. The valve tab 208 passes through the compression point during the transition from the closed position to the open position and during the transition from the open position to the closed position. In some examples, the consistency of the shape of the valve tab 208 and the dimensions of the slits 230, 232 allows the valve to open and close symmetrically (e.g., the valve tab 208 opens and closes simultaneously).

[0056] After the point of the valve tab 208 passes the pivot point 226, the resilient material of the valve tab 208 can relax. The valve 106 can further open due to the flow pressure of the fluid being dispensed, the flexibility of the hinge segment 204, and / or the deformation of the valve tab 208. In the open position, a pressure less than the check pressure can hold the valve 106 in the open position. For example, the valve 106 can have a forward check pressure between 6-7 psi to transition from the closed position to the open position, and a full flow forward flow pressure of 2-3 psi can hold the valve in the open position. In the open position, the valve 106 allows a high flow rate with a low flow pressure and a low fluid velocity. In other examples, the valve 106 can have a forward check pressure of about 1.5 psi or greater and a full flow forward flow pressure of about 0.6 psi. The full flow forward flow pressure can be affected by, for example, the viscosity of the fluid flowing through the valve. In some cases, the full flow forward flow pressure of the fluid can be greater than the pressure that holds the valve in the open position and the check pressure of the valve.

[0057] The valve 106 can be used with fluids having a wide range of thermal physical and transport properties. For example, the valve can be used with high and low viscosity liquids (e.g., having a viscosity in the range of 1 cP to 10,000 cP). The valve can also be used with high and low surface tension liquids. The symmetrical opening and closing behavior of the valve can prevent spitting or dripping during opening or closing, regardless of the properties of the liquid.

[0058] In the closed position, the thickness 224 of the valve lobe 208 allows the valve lobe 208 to locally deform around particles (e.g., seeds and fibers) suspended in the fluid that can stick to the valve lobe 208. The valve lobe 208 can form a fluid seal and provide a back pressure due to the local deformation in the presence of the particles.

[0059] Figures 3A-3B An example valve 106 is shown in an open position. The tip 300 of the valve lobe 208 is bent outward in the direction of the outlet side 212, forming an opening 302 through the central portion 206 of the valve 106. The hinge section 204 allows the valve lobe 208 to move. In the open position, the rim 202 can remain undeformed. The valve 106 can be held in the open position by fluid flow through the opening 302. The valve 106 can be transitioned from the open position to the closed position by reducing the flow pressure below the pressure required to keep the valve lobe 208 open. For example, the pressure can be reduced by reducing the flow rate of the fluid flowing through the opening 308. A negative pressure or suction pressure can also be provided at the inlet side of the valve to transition the valve from the open position to the closed position. For example, reversing the flow direction of the fluid can provide a suction pressure to close the valve 106. In some applications, the pump of the fluid dispensing system can quickly reverse the flow direction to close the valve. In some applications, the retraction of the sidewall of a squeeze bottle can provide a suction pressure to close the valve 106. This dynamic closing behavior can allow the valve 106 to close in a drip-free manner.

[0060] In some applications, the rim 202 includes a sealing bead 304 located on the inlet side 210 of the valve body 200. The sealing bead 304 can provide a seal between the pump outlet (e.g., 114) and the valve 106 at low deformation of the valve 106. An elastomeric material can behave like a hydraulic fluid (e.g., compression of the elastomer at one place can cause the elastomer to expand elsewhere). A narrow sealing bead has a small volume, but has a local high compression force to form a seal. In this way, the deformation of the valve can be limited while forming a fluid tight seal. The deformation of the valve 106 can also be limited by a retaining ring (e.g., retaining ring 120). The retaining ring can provide geometric stability to the valve 106. If the geometric stability of the valve 106 is not maintained (e.g., the valve deforms), the contact surface 308 of the valve lobe 208 can be affected, thereby reducing the performance of the valve 106.

[0061] Figure 4A cross-sectional view of an exemplary outlet 400 of a fluid dispensing system (e.g., 100) is shown. The outlet 400 includes a housing 402, a valve 404, and a retaining ring 406. The outlet 400 can be, for example, an outlet of a pump, and the housing 402 can be a pump housing. Other examples of the housing 402 include a pipe, a hose, a tube, a reservoir housing, or a cap of a squeezable bottle. The inlet side 408 of the valve 404 is pressed against the housing 402 by the retaining ring 406 to form a seal around the rim 410 of the valve 404. The housing 402 can include a sealing bead 412. Alternatively, the rim 410 can include a sealing bead (e.g., the sealing bead 304); in either case, the sealing bead 412 creates a locally high interference pressure between the valve 404 and the housing 402 to act as a seal against flow pressure, such that fluid flows out through the valve lobes 414. The circular opening 415 in the retaining ring 406 has a diameter similar to the inner diameter 416 of the rim of the valve.

[0062] The compression force that seals the valve rim 410 to the housing 402 can transmit a force that causes the valve lobes 414 to deform. This can cause the valve 404 to leak in the closed position, and / or the valve lobes 414 can close asymmetrically under dynamic conditions, with one lobe riding on an adjacent lobe. In some applications, deformation of the valve lobes 414 is prevented by providing the valve 404 with an outer diameter 417 that is sized to match the inner diameter 418 of the housing 402, and a rib 420 formed on the housing 402 that is sized to match the inner diameter 416 of the rim 410, so the resilient rim 410 is dimensionally constrained by the rigid housing 402 and rib 420. The valve 404 can transition symmetrically from the open position to the closed position without introducing or entraining air through the valve in the opposite direction.

[0063] The valve 404 can have a lower opening pressure (e.g., reverse check pressure) under reverse flow conditions than under forward flow conditions. The lower reverse check pressure results from the location of the hinge point 430 relative to the outlet side 432 of the valve lobes 414. In some applications, it can be desirable to have a higher opening pressure under reverse flow conditions, for example in the case of a cleaning fluid being injected under pressure into a downstream tube near the outlet side 432 of the valve 404 to clean the downstream tube. If the cleaning fluid passes through the valve 404, the cleaning fluid can contaminate the fluid in the reservoir. The length of the rib 420 in the housing 402 can partially prevent the valve from opening in the opposite direction. To further increase the reverse check pressure, a small inner diameter upstream orifice or backing washer can be inserted adjacent the inlet side 408 of the valve 404, overlapping the exterior of the valve lobes 208. The orifice or backing washer can support the valve lobes 414. A smaller orifice in the washer results in a higher reverse flow check pressure.

[0064] Figure 5AA cross-sectional view of an exemplary outlet 500 of a fluid dispensing system (e.g., 100) is shown. The outlet 500 includes a housing 502 with an outlet orifice 504, a valve 506 adjacent to the outlet orifice 504, and an annular ring 508 that holds the valve 506 in a fluid tight seal over the outlet orifice 504. The diameter of the outlet orifice 504 is smaller than the diameter of the valve lobe 512. In this configuration, the outlet orifice 504 supports the inlet side 514 of the valve lobe 512, increasing the reverse check pressure to open the valve 506 under reverse flow conditions. The diameter of the outlet orifice 504 inversely affects the reverse check pressure. For example, decreasing the diameter of the outlet orifice 504 will increase the reverse check flow pressure, while increasing the diameter will decrease the reverse check pressure.

[0065] Figure 5B A cross-sectional view of an exemplary outlet 550 of a fluid dispensing system is shown, where a backing washer 552 is inserted between the outlet orifice 504 of the housing 556 and the inlet side 558 of the valve 560. The use of a backing washer 552 can allow for customization of the reverse check pressure depending on the specific application and fluid being dispensed. Like the diameter of the outlet orifice, the inner diameter of the backing washer 552 has an inverse relationship with the reverse check pressure.

[0066] Figure 6 A plan view of an exemplary valve 600 including six valve lobes 602 is shown. The annular rim 604 and hinge section 606 of the valve body 608 can maintain similar geometry as the other exemplary valves previously described. In this example, the six valve lobes 602 are defined by three intersecting cuts or slits 610. In some applications, the valve can have more than six valve lobes. In some cases, the valve can have an odd number of valve lobes. An advantage of increasing the number of valve lobes is having a larger open aperture when the valve is in the open position. There can be a tradeoff between having a larger open aperture and the valve maintaining symmetrical closing behavior, as more and smaller tips of the valve lobes 602 can increase the likelihood of the valve lobes overlapping with adjacent valve lobes during closing.

[0067] Figure 7 A plan view of an exemplary valve 700 is shown, including six valve lobes 702 and a hexagonal annular groove 704 located in the hinge section 706. The valve body 708 in this example is still circular. As shown by the hexagonal annular groove 704, an advantage of having straight sections 710 of the annular groove is more precise control of the articulation of the valve lobes 702 when opening the valve. The straight sections 710 can be used with any number of valve lobes. In some applications, the thickness of the resilient material in the hinge section 706 can be adjusted to change the flow pressure required to hold the valve 700 in the open state. To mitigate valve warping and deformation, as discussed with respect to Figure 4 the outlet housing can be provided with a circular outer diameter and hexagonal ribs to match the geometry of the valve 700.

[0068] Figures 8A-8C Example valve configurations with different numbers of valve lobes are shown. Figure 8A An example valve 800 is shown with a circular valve body 802 and three valve lobes 804 and an annular groove 806 with three straight segments 808 having a triangular shape. Figure 8B An example valve 810 is shown with four valve lobes 804 and four straight segments 808 defining a square annular groove 806. Figure 8C An example valve 820 is shown with a circular valve body 802 and five valve lobes 804. Five straight segments 808 define a pentagonal annular groove 806.

[0069] Figure 8D A cross-section of an example valve 830 is shown. In this example, the plurality of valve lobes 832 have a first thickness 834 near the hinge segment 836. The thickness of the plurality of valve lobes 832 increases from the hinge segment 836 to the center 838 of the valve 830. The center 838 of the valve has a second thickness 840 that is greater than the first thickness 834.

[0070] Figure 9 is a flowchart of an example method 900 for dispensing a fluid. The valve is opened by providing a fluid pressure to the inlet side of the valve (step 905). The fluid pressure is greater than the check pressure of the valve so as to open the valve. The fluid pressure can be provided, for example, by a pump of a dispensing system. In some applications, the fluid pressure can be provided by increasing the pressure in a fluid reservoir, for example, by squeezing the reservoir. The fluid is dispensed through the valve (step 910). In some applications, the flow pressure that keeps the valve open can be less than the check pressure of the valve. A high flow rate can be maintained during the dispensing step. The valve is closed by providing a suction pressure to the inlet side of the valve (step 915). The suction pressure can be created by reducing the flow pressure below that required to keep the valve in an open position. The suction pressure can be created by reversing the flow direction. The valve can close in a symmetrical manner, preventing unwanted spraying or spattering. In some applications, the valve closes without dripping the dispensed fluid. In some cases, the valve can close without introducing air through the valve in the reverse flow direction.

[0071] A number of applications of the systems and methods have been described. Nevertheless, it will be understood that various modifications can be made without departing from the scope of the disclosure. Accordingly, other embodiments are within the scope of the following claims.

Claims

1. A check valve, comprising: a valve body formed of a resilient material, the valve body having an inlet side and an outlet side, and comprising: a rim forming an outer perimeter of the valve body; a hinge section comprising an annular groove formed on the inlet side of the valve body radially inward of and adjacent to the rim; and a plurality of tabs formed at a center of the valve body by one or more slits extending radially outward from the center of the valve body toward the hinge, and wherein, in a closed position, the hinge section is coplanar with the plurality of tabs.

2. The check valve of claim 1, wherein, a surface extending at least from the center to the hinge and including the hinge is planar on the outlet side of the valve body.

3. The check valve of claim 1, wherein, the annular groove comprises a triangle, a square, a pentagon, or a hexagon.

4. The check valve of claim 1, wherein, a thickness of the hinge section is less than a thickness of the plurality of tabs.

5. The check valve of claim 4, wherein, the annular groove defines a hinge point of the plurality of tabs, the hinge point offset from a vertical center of the valve body toward the outlet side of the valve body.

6. The check valve of claim 1, wherein, a check pressure of the check valve is determined by an offset distance between the hinge point of the plurality of tabs and a midpoint of the thickness of the plurality of tabs.

7. The check valve of claim 6, wherein, the offset distance is determined by a depth of the annular groove.

8. The check valve of claim 1, further comprising an annular sealing bead protruding from the rim on the inlet side of the valve body.

9. The check valve of claim 1, further comprising: an open position, wherein the plurality of tabs are hinged outward from the valve body, thereby allowing fluid communication from the inlet side to the outlet side, wherein a pressure to maintain the check valve in the open position is less than a check pressure of the check valve.

10. A dispensing system, comprising: a reservoir; a pump comprising an inlet and an outlet, the inlet fluidly coupled to the reservoir; a valve fluidly coupled to the outlet of the pump, the valve comprising: a valve body formed of a resilient material, the valve body having an inlet side and an outlet side, and comprising: a rim forming an outer perimeter of the valve body; a hinge section comprising an annular groove formed on the inlet side of the valve body radially inward of and adjacent to the rim; and a plurality of tabs formed at a center of the valve body by one or more slits extending radially outward from the center of the valve body toward the hinge, and wherein a surface extending at least from the center to the hinge and including the hinge is planar on the outlet side of the valve body.

11. The system of claim 10, further comprising a ring defining a central opening therein, the ring connected to an outlet of the pump, wherein, the rim of the valve is held between the annulus and the outlet of the pump.

12. The system of claim 10, wherein, the valve provides a check pressure against forward flow, the check pressure being greater than a hydrostatic pressure from fluid in the reservoir when the reservoir is full.

13. The system of claim 10, wherein, the pump provides sufficient pressure to open the valve.

14. The system of claim 10, wherein, the valve comprises: a closed position, wherein edges of the plurality of tabs are coplanar with the valve body, thereby preventing fluid communication through the valve; and an open position, wherein the plurality of tabs are hinged outward from the valve body, thereby allowing fluid communication from the inlet side to the outlet side. an open position in which the plurality of tabs articulate outwardly from the valve body, thereby allowing fluid communication from the inlet side to the outlet side, and wherein edges of the plurality of tabs on the inlet side of the valve body are compressed when transitioning from the closed position to the open position.

15. The system of claim 14, wherein, the valve is configured to transition from the open position to the closed position in response to negative pressure at the inlet side.

16. The system of claim 15, wherein, no air is entrapped into the reservoir when the valve transitions from the open position to the closed position.

17. The system of claim 10, wherein, the valve and the pump are integrated with the reservoir as a disposable item.

18. The system of claim 10, wherein, a reverse check pressure of the valve is determined by an inner diameter of an outlet of the pump.

19. The system of claim 10, further comprising: a backing washer having an inner diameter that is smaller than an inner diameter of an outlet of the pump, the backing washer positioned between the outlet of the pump and the inlet side of the valve body, wherein a reverse check pressure of the valve is determined by the inner diameter of the backing washer.

20. A method for dispensing a fluid, comprising: opening a valve by providing fluid pressure to an inlet side of the valve, the fluid pressure being greater than a check pressure of the valve; dispensing the fluid through the valve; and closing the valve by providing negative pressure to the inlet side of the valve.

21. The method of claim 20, wherein, closing the valve includes providing the negative pressure by reversing a flow direction of the fluid.

22. The method of claim 20, wherein, dispensing the fluid includes a fluid flow pressure that is less than the check pressure of the valve.

23. The method of claim 20, wherein, closing the valve does not introduce air through the valve.

24. The method of claim 20, wherein, closing the valve includes closing the valve symmetrically.

25. The method of claim 20, wherein, closing the valve includes closing the valve without dripping the dispensed fluid.

26. A valve, comprising: a valve body formed of an elastomeric material, the valve body including: an inlet side; an outlet side including a flat surface; a rim having a first thickness and forming an outer perimeter of the valve body; a hinge section having a second thickness and positioned inward of the rim and adjacent to the rim, the hinge section defining a pivot point arranged closer to the outlet side than to the inlet side; and a plurality of tabs having a third thickness that is greater than the second thickness, the plurality of tabs formed at a center of the valve body by one or more slits extending radially outward from the center of the valve body toward the hinge section.

27. The valve of claim 26, wherein, the third thickness increases from the hinge section to the center of the valve body. the third thickness increases from the hinge section to the center of the valve body.

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