Patent Description:
Diaphragm-type fluid control valves can provide controlled fluid separation and flow along a pipe-line, manifold or other piping network. Generally, the diaphragm-type valve includes a flexible diaphragm element to control fluid flow between the inlet and the outlet of the valve body. More specifically, in known diaphragm-type valves, the flexible element engages a seat formed within the valve body to separate the interior chamber of the valve body into three parts: (i) the inlet chamber which can hold the supply fluid, (ii) and outlet chamber which receives fluid from the inlet chamber for discharge out the outlet and (iii) a diaphragm chamber which can hold a fluid under pressure to maintain the diaphragm element in the seated position. Upon release of fluid pressure from the diaphragm chamber, the diaphragm element can be displaced from the seated position by the pressure of fluid in the inlet chamber and fluid flow is permitted between the inlet and the outlet chambers.

To ensure the diaphragm seals properly, the above-described diaphragm-type valves require a bias force to urge the diaphragm towards the valve seat even when there is fluid pressure in the inlet chamber. This is because, in typical systems, the source of the fluid to the diaphragm chamber is the inlet of the valve itself. Thus, when the diaphragm chamber has fluid under pressure, the pressure in the diaphragm chamber is equal to the inlet. This means that, while releasing the fluid pressure in the diaphragm chamber opens the valve, when the pressure is restored to the diaphragm chamber, the forces on each side of the diaphragm will be balanced until the diaphragm actually seats. Accordingly, to ensure the diaphragm is forced to the valve seat, a bias is needed to urge the diaphragm to the closed position. To this end, International Patent Publication No. <CIT> discloses a diaphragm with an elastomeric ring element disposed near an outer circumference of the diaphragm to urge the diaphragm member to a closed position. Specifically, the outer angled surface of the elastomeric ring element engages and provides pressure contact with a portion of the interior surface of the valve body to assist in urging the diaphragm towards its sealing position to permit closure of the valve. The diaphragm can also include one or more rib members and an interior ring disposed in a central portion of the upper surface of the diaphragm to further urge the diaphragm to the seated position. Similarly, in <CIT>, the diaphragm is configured to include ribs and/or a ring that is attached to the diaphragm to bias the diaphragm towards the sealing position. Specifically, the upper face of the diaphragm has tangential ribs and radial ribs to urge the diaphragm towards the valve seat on the valve body. In addition, the diaphragm also includes a flexible ring element that is in pressure contact with the body of the valve to urge the diaphragm towards the seat to close the valve. However, the design and manufacturing process of the diaphragms will need to account for the ribs and or rings, which can produce added complexity and/or expense in manufacture.

In some known valves, springs and/or other biasing devices engage the diaphragm such that, when the pressure in the diaphragm chamber is restored and the forces balance, the spring (or another biasing device) can urge the diaphragm to the closed position. For example, in UK Patent Application No. <CIT>, a spring engages the diaphragm on an upper side of the diaphragm to force a lower side of the diaphragm to make contact with the valve seat. Once contact is made, the forces, due to the fluid pressures, are no longer balanced and the force on the upper side of the valve will be greater. However, to accommodate the spring, the upper cover of the valve must be made larger than needed and/or include features to receive the spring. In addition, at low rates, the biasing device can create vibrations that damage the diaphragm. Further, separate biasing devices such as springs can complicate the assembly of the valve and add extra costs to the valve assembly. Moreover, the closing force generated by the spring can produce an unacceptable pressure loss in the valve.

Moreover, in the above-discussed systems, the diaphragm is attached to the valve by disposing a portion of the diaphragm between the cover portion and body portion and clamping the cover portion to the body portion. For example, the valve assembly can be securely connected using bolts and/or threaded studs that clamp the cover portion to the body portion with the diaphragm disposed in the middle. However, in the typical system, the bolts and/or threaded studs also go through the diaphragm, which has corresponding holes to receive the bolts or threaded studs. Such an arrangement provides high stress concentrations on the diaphragm around the holes during the open/close cycles of the valve. The stress on the diaphragm can lead to damage and premature failure of the diaphragm. <CIT> appears to disclose a deformable membrane that is clamped between two flanges without bolts going through the membrane. However, only one of the flanges has a groove or channel to receive the outer edge of the deformable membrane while the other flange has a flat surface. Thus, one side of the deformable membrane is pressed against the flat surface of the flange when the valve is assembled. Because one of the flanges has a flat surface, the valve could be susceptible to leakage if there is a flaw or imperfection in either the flat surface of the flange or the deformable member.

Further limitation and disadvantages of conventional, traditional, and proposed approaches to diaphragm-type valve configurations will become apparent to one skilled in the art, through comparison of such approaches with embodiments of the present invention as set forth in the remainder of the present disclosure with reference to the drawings.

<CIT> discloses a diaphragm-type valve including a cover portion with a first channel, a body portion with a second channel and, a diaphragm with a flexible member, a substantially smooth wall portion and a lip.

The invention provides a fluid control valve according to claim <NUM>. Preferred embodiments of the present invention, as disclosed in the dependent claims, provide for a more precise control of the fluid flow and/or pressure in diaphragm-type control valves by employing a diaphragm having a simple construction with minimal stress concentrations during operation. The cavity is configured to receive the lip member and engage with the lip member such that the cover portion and body portion pinch or squeeze the lip member to securely hold the diaphragm and seal the control valve when the cover portion and the body portion are securely connected. Preferably, by securing the lip member between the cover portion and the body portion, the lip member creates a tension force within the flexible member when the flexible member is in the inverted position due to the pressure on the lower surface of the flexible member. Preferably, the cover portion is securely connected to the body portion using, e.g., bolts and/or threaded studs. Preferably, the connecting means, e.g., the bolts and/or threaded studs do not go through the diaphragm. Preferably, the bolt or threaded stud pattern is disposed on the valve body such that the bolts and or threaded studs do not penetrate diaphragm. That is, the bolts and or threaded studs are disposed outside the outer perimeter of diaphragm.

Preferably, when the pressure in the diaphragm chamber is released, the flexible member has a natural-inverted or partially inverted position in which the flexible member is upturned inside-out due to the pressure on the lower surface of the diaphragm "Natural-inverted position" means the diaphragm shape in an inverted position corresponds to its natural full inverted state, for example, a hemisphere. When in the natural-inverted or partially inverted position, preferably, the upper surface conforms to a shape or profile of at least a portion of the inner surface of the cover to define a passageway that permits communication between the inlet and the outlet. "Conforms to" means that a surface of the flexible member generally follows the contour of an opposing surface and rests against at least a portion of the opposing surface. "Rests against" as used herein means that a contact between a surface of the flexible member and a second surface is such that the second surface aids in supporting the flexible member. Preferably, when inverted, the flexible member conforms to the inner surface of the cover. Preferably, at least a middle portion of the upper surface of the flexible member conforms to a profile of the inner surface of the cover portion when the flexible member is in the inverted position. In some embodiments, substantially the entire upper surface of the flexible member conforms to the profile of the inner surface of the cover portion. In some embodiments, the profile of the middle section of the inner surface of the cover portion can be a smooth concave surface. Preferably, the entire profile of the cover portion is a smooth concave surface. In other preferred embodiments, the profile can have other textures, shapes and/or contours.

The inner surface of the lower valve body can include one or more elongated seat members. Preferably, each elongated seat member is substantially aligned along the plane. Preferably, when in the non-inverted position (lower position), the flexible member conforms to and seals against each elongated seat member so as to prevent fluid communication between the inlet and the outlet Preferably, the lower surface of the flexible member and each elongated seat member have corresponding radius of curvatures such that the flexible member conforms to and seals against each elongated seat member when the flexible member is in the non-inverted position (lower position). "Corresponding radius of curvatures" means a radius of curvature of the lower surface of the flexible member is substantially equal to a radius of curvature of an elongated seat member and/or a radius of curvature of a support member, as appropriate. For example, the radius of curvature of the lower surface of the flexible member is within ± <NUM>% of the radius of curvature of an elongated seat member and or the radius of curvature of a support member, as appropriate. Preferably, the corresponding radius of curvatures are within ± <NUM>%, more preferably within ± <NUM> %, even more preferably within ± <NUM> %, and still even more preferably within ± <NUM>%. In some embodiments, the flexible member can include one or more elongated members protruding from the lower surface. Preferably, when the flexible member is in its natural non-inverted position (lower position), each protruding elongated member contacts an elongated seat member and seals against the seat member so as to prevent fluid communication between the inlet and the outlet Once the protruding elongated member makes contact with the elongated seat member, the force on the upper surface of the flexible member will be greater than the force on the lower surface and the flexible diaphragm will firmly seal.

Preferably, the diaphragm member includes a reinforced fabric embedded in a rubber matrix. Because the reinforced fabric does not stretch as much as the rubber, a tension force is mostly concentrated in the reinforced fabric when the flexible member is forced to the inverted position. In some embodiments, the diaphragm is constructed such that, when the diaphragm is in the inverted position, a tension force within the diaphragm is such that it exclusively biases the flexible member to the lower position. "Exclusively biases" means that additional diaphragm structures such as, e.g., ribs and rings and biasing devices such as springs are not used to urge the flexible member to the lower position to seal against the elongated seat member.

According to the invention, the flexible member has an upper surface having a substantially smooth wall portion. For example, the upper surface can have a constant radius of curvature and can be, e.g., bowl-shaped. The substantially smooth wall portion circumscribes a substantially smooth central portion that, preferably, has an infinite radius of curvature. The central portion is a flat surface. The lower surface of the flexible member can have any texture. In some embodiments, the lower surface has a substantially smooth surface except for at least one elongated member disposed on the lower surface. "Substantially smooth" as used herein means a continuous level surface that has a constant radius of curvature or a slightly varying radius of curvature that approximates a constant radius of curvature without significant convex portions, or an infinite radius of curvature or a substantially infinite radius of curvature approximating a flat surface that is within manufacturing tolerances based the method of manufacture and the properties of the materials used for the diaphragm. For example, a diaphragm with a substantially smooth surface can include non-functional features and structures such as, e.g., seams, minor imperfections, and minor variations in radius. In contrast, known diaphragms have ribs and/or other support structures, which means that the surface of the known diaphragms have numerous structures with varying radius of curvatures.

The flexible member of the preferred control valve, preferably, axially separates two sub-chambers from one another. Preferably adjacent each of the two axially separated sub-chambers is a diaphragm chamber for controlled operation of the diaphragm, i.e., controlled operation of the flexible member between the inverted and lower positions. The preferred orientation of the diaphragm chamber relative to the axially spaced chambers provides that the diaphragm chamber can seal the axially spaced sub-chambers from one another with a diaphragm fluid pressure that is at the inlet sub-chamber pressure. Moreover, the preferred control valve, the diaphragm, and orientation of the sub-chambers provide for a controlled seal between the axially spaced sub-chambers that can compensate for fluctuations and surges in the fluid pressure in either of one of the two axially separated chambers. In one aspect, the preferred control valve can be installed in piping systems, such as for example, preaction fire protection systems that are known in the art. Thus, the preferred control valve can provide for a single and preferably substantially constant pressure between the control valve and, e.g., a network of sprinklers. In some embodiments, the preferred control valve includes an intermediate chamber in between the two sub-chambers. The intermediate chamber of the preferred control valve fills with pressurized fluid when the control valve is operated or the valve seal is improper. Preferably, the intermediate chamber is connected to an alarm. In some embodiments, the intermediate chamber provides for a drain to atmosphere.

In some embodiments, the inner surface of the body portion preferably includes a bridge element substantially aligned along the plane and preferably including a least two elongated seat members and a groove disposed between the elongated seat members. A portion of the body portion further preferably defines a port in communication with the groove. Preferably, the lower surface of the flexible member includes a pair of spaced apart elongated members defining a channel therebetween. The elongated members of the flexible member preferably are in sealed engagement with the a least two elongated seat members when in the non-inverted position such that the channel is in communication with the groove and the port.

Accordingly, the various preferred embodiments of the preferably hydraulically operated control valve, its diaphragm and method of operating can provide one or more of the following features: a design that employs a minimum number of moving components to reduce wear, a simplified flexible diaphragm configuration, a valve construction that facilitates easy assembly and serviceability, and reliable performance. In claim <NUM>, the The invention also provides a method of operating a fluid control valve having a cover portion with a first channel, a body portion having a second channel, and a diaphragm having a flexible member that has an upper surface and a lower surface and a lip member circumscribing the flexible member.

Exemplary embodiments of the present invention are directed to a diaphragm-type control valve with a simplified diaphragm configuration. Shown in <FIG> is an exploded view of the preferred valve <NUM> showing the internal components of the valve <NUM>. The valve <NUM> includes a valve body <NUM> through which fluid can flow in a controlled manner. The control valve <NUM> is preferably configured for installation in a piping manifold or other piping assembly to separate and control fluid flow between a first fluid volume and a second fluid volume. For example, in a fire system type application, the control valve <NUM> provides a diaphragm-type hydraulic control valve for preferably controlling the release and mixture of a first fluid volume having a first fluid pressure, such as for example a water main, with a second fluid volume at a second fluid pressure, such as for example, compressed gas contained in a network of pipes. Accordingly, the control valve <NUM> can provide fluid control between fluids or various media including liquids, gasses or combinations thereof.

The control valve <NUM> includes a valve body <NUM> preferably constructed in two parts: (i) a cover portion 12a and (ii) a body portion 12b. "Body portion" is used herein as a matter of reference to a lower portion of the valve body <NUM> that is coupled to the cover portion 12a when the control valve is fully assembled. Preferably, the valve body <NUM> and more specifically, the body portion 12b includes an inlet <NUM> and outlet <NUM>. Each of the inlet and outlet <NUM>, <NUM> of the valve body <NUM> includes an appropriate end fitting for coupling to a manifold. For example, inlet <NUM> preferably includes a coupling to a first fluid supply line, such as for example a water main, and the outlet <NUM> also preferably includes a coupling to another pipe fitting such as, for example, a discharge pipe coupled to a network of interconnected pipes. The control valve <NUM> can be installed in either a horizontal orientation such that fluid entering the inlet <NUM> at one elevation is discharged from the outlet <NUM> at the same elevation, or alternatively, the control valve <NUM> can be installed in a vertical orientation such that fluid entering the inlet at one elevation is discharged from the outlet at a different elevation.

The inlet <NUM>, outlet <NUM> and valve body <NUM> can be sized so as to provide a range of valve sizes for coupling to corresponding nominal pipe sizes. Preferably, the inlet <NUM>, outlet <NUM> and valve body <NUM> define valve sizes of <NUM> (<NUM> inch) (<NUM> DN) and larger and more specifically valve sizes of <NUM> (<NUM> inch) (<NUM> DN), <NUM> (<NUM>-<NUM>/<NUM> inch) (<NUM> DN), <NUM> (<NUM> inch) (<NUM> DN), <NUM> (<NUM> inch) (<NUM> DN), <NUM> (<NUM> inch) (<NUM> DN), <NUM> (<NUM> inch) (<NUM> DN), <NUM> (<NUM> inch) (<NUM> DN), <NUM> (<NUM> inch) (<NUM> DN), and <NUM> (<NUM> inch) (<NUM> DN), which respectively accommodate nominal pipe sizes of <NUM> (<NUM> inch) (<NUM> DN), <NUM> (<NUM>-<NUM>/<NUM> inch) (<NUM> DN), <NUM> (<NUM> inch) (<NUM> DN), <NUM> (<NUM> inch) (<NUM> DN), <NUM> (<NUM> inch) (<NUM> DN), <NUM> (<NUM> inch) (<NUM> DN), <NUM> (<NUM> inch) (<NUM> DN), <NUM> (<NUM> inch) (<NUM> DN), and <NUM> (<NUM> inch) (<NUM> DN). However, other valve sizes that accommodate other nominal pipe sizes can be provided. Preferably, in constructing the valve body <NUM>, the cover portion 12a and the body portion 12b are separately cast and machined to provide the preferred openings and surface treatments such as threaded openings. However, other processes for construction and manufacturing can be used. The valve body <NUM> is preferably cast from ductile iron however other materials may be used provided they are suitable for a given fluid flow application. Preferably, a pressure rating of the valve <NUM> is about <NUM> MPa (<NUM> psi).

In some embodiments, the valve body <NUM> can include a port <NUM> (see, e.g., <FIG>) in the valve body <NUM> to provide means for an alarm system monitoring the valve for any undesired fluid communication from and/or between the inlet <NUM> and the outlet <NUM>. For example, the port <NUM> can be used for providing an alarm port to the valve <NUM> so that individuals can be alerted as to any gas or liquid leak from the valve body <NUM>. More specifically, the port <NUM> can be coupled to a flow meter and alarm arrangement to detect the fluid or gas leak in the valve body. In addition, the port <NUM> is preferably open to atmosphere and, as discussed below, in communication with an intermediate chamber disposed between the inlet <NUM> and the outlet <NUM>. The port <NUM> can include an appropriately threaded opening or other mechanical fastening member for coupling an appropriate pipe fitting or nipple to the given orifice.

As shown in <FIG>, disposed between the cover portion 12a and the body portion 12b is a diaphragm <NUM>. The diaphragm <NUM> includes a flexible preferably elastomeric member 100a, a lip member 100b that circumscribes the flexible member 100a, and a tab 100c that is used to align the diaphragm <NUM> in the control valve <NUM>. The cover portion 12a and the body portion 12b each include an inner surface such that when the cover portion 12a and body portion 12b are joined together, the inner surfaces further define a chamber <NUM>. As seen in <FIG>, the body portion 12b preferably includes a notch <NUM> for receiving the tab 100c and properly aligning the diaphragm <NUM> within the chamber <NUM>. In some exemplary embodiments, diaphragm <NUM> can have two or more tabs and the body portion 12b can have two or more corresponding notches for alignment purposes. In addition, because the bolts do not go through the diaphragm <NUM> to provide support, preferably pins (not shown), e.g., in the tabs or another location, can be used to hold the diaphragm <NUM> in place until the cover portion 12a is attached when the valve <NUM> is mounted vertically. The chamber <NUM>, being in communication with the inlet <NUM> and the outlet <NUM>, further defines a passageway through which a fluid, such as water, can flow. Disposed within the chamber <NUM> is the flexible member 100a for controlling the flow of fluid through the valve body <NUM>. The flexible member 100a provides selective communication between the inlet <NUM> and the outlet <NUM>.

The diaphragm <NUM> has at least two positions within the chamber <NUM>: a lower most fully closed or sealing position (see, e.g., <FIG>) and an upper most or fully open position (see, e.g., <FIG>). As the diaphragm <NUM> moves to the upper most or fully open position, the diaphragm <NUM> and body portion 12b define a passageway that permits communication between the inlet <NUM> and the outlet <NUM>. Preferably, at some point between the fully closed position and the fully open position, a cross-sectional area of the passageway is such that there is sufficient flow through the control valve <NUM> and the pressure drop in the control valve <NUM> is minimized. Preferably, the diaphragm <NUM> is constructed so as to move to the natural-inverted position. In the natural-inverted position, as seen for example in <FIG>, the flexible member 100a conforms to at least the profile of the central section <NUM> (see FIG. SA) of the first inner surface <NUM> of cover portion 12a. In the lower most closed or sealing position, as seen for example in <FIG>, the diaphragm <NUM> engages a seat member <NUM> on bridge element <NUM> as seen in <FIG>, which is constructed or formed as an internal rib or middle flange within the inner surface of the valve body <NUM>, thereby sealing off communication between the inlet <NUM> and the outlet <NUM>. With the diaphragm <NUM> in the closed position (see <FIG>), the diaphragm <NUM> preferably dissects the chamber <NUM> into at least three regions or sub-chambers 24a, 24b and 24c. More specifically, formed with the diaphragm <NUM> in the closed position is a first fluid supply or inlet sub-chamber 24a in communication with the inlet <NUM>, a second fluid supply or outlet sub-chamber 24b in communication with the outlet <NUM> and a diaphragm sub-chamber 24c. The cover portion 12a preferably includes a central opening <NUM> for introducing an equalizing fluid into the diaphragm sub-chamber 24c. By equalizing the pressure between sub-chamber 24c and sub-chambers 24a and 24b, the tension within the diaphragm <NUM> (e.g., in layer <NUM>, which is, for example, a reinforced fabric) urges the flexible member 100a to the lower position. In some embodiments, the inversion inhibitor <NUM>, which is described below, creates a tension force within the flexible member 100a that aids in urging the flexible member 100a to the lower position. Once the diaphragm <NUM> makes contact with the seat member <NUM>, the pressures are no longer equalized on each side of the flexible member 100a, and the corresponding difference in the forces holds the diaphragm <NUM> against seat member <NUM>.

As seen in <FIG>, the preferred diaphragm member <NUM> is configured to engage and cooperate with the inner surfaces of the cover portion 12a and body portion 12b to define the three sub-chambers 24a, 24b, 24c in an orientation that can provide for a diaphragm sub-chamber 24c that can effectively compensate for fluctuations and/or surges in fluid pressure in either one of the inlet and outlet sub-chambers 24a, 24b. Preferably, the equalizing fluid is provided from the first fluid source such that any surges in flow or pressure experienced at the inlet sub-chamber 24a is also experienced in the diaphragm sub-chamber 24c. In this manner, the diaphragm sub-chamber 24c can react and compensate with a diaphragm pressure to maintain the flexible member 100a in the lower position.

The material to be used for manufacturing the diaphragm <NUM> is dependent on the type of fluid being carried and on the temperature range to which the diaphragm is to be exposed. Preferably, the upper and lower layers <NUM>, <NUM>, respectively of the diaphragm <NUM> are constructed from layers of elastomeric material having a durometer hardness or shore value of about <NUM> to <NUM>, and preferably about <NUM> to <NUM>, and a minimum tensile strength of about <NUM> MPa (<NUM> pounds per square inch). Suitable materials for use at the upper and lower layers <NUM>, <NUM> include, for example, natural rubber, nitrile butadiene rubber, neoprene, ethylene propylene diene monomer (EPDM), or another appropriate elastomer. Materials that can be used for reinforcements between the upper and lower surface layers at middle layer <NUM> of the diaphragm <NUM> include a fabric made of, for example, cotton, polyester, and nylon and more preferably, nylon no. <NUM> reinforced material. Thus, in preferred embodiments, the diaphragm <NUM> includes a reinforced fabric embedded in a rubber matrix. When the diaphragm <NUM> is in the inverted position, the tension force is concentrated in the reinforced fabric. Preferably, two layers of reinforced fabrics are disposed at a <NUM> degree angle to each other with respect to a weave pattern of reinforced fabrics. By arranging the reinforced fabrics at <NUM> degrees to each other, the stresses on the diaphragm <NUM> (due to the pressure on the lower surface 104a of the flexible member 100a) are evenly distributed.

In operation, the equalizing fluid can be relieved from the diaphragm sub-chamber 24c in preferably a controlled manner to urge the diaphragm member <NUM> to the open or actuated position, in which the diaphragm member <NUM> is inverted and spaced from the seat member <NUM> thereby permitting the flow of fluid between the inlet <NUM> and the outlet <NUM>. Preferably, the diaphragm <NUM> conforms to at least a portion of the inner surface <NUM> of the cover portion 12a. In some embodiments, the diaphragm <NUM> conforms to substantially the entire inner surface <NUM> of the cover portion 12a. The fluid release from the diaphragm sub-chamber 24c can be regulated by way of, for example, an electrically controlled solenoid valve, such that the diaphragm member <NUM> can achieve regulated positions between the fully closed position and the fully open position. Accordingly, the diaphragm member <NUM> is preferably electrically actuated between the open and closed positions. Alternatively, the diaphragm can be actuated, regulated and or closed or latched by other mechanisms such as, for example, a mechanical latching mechanism.

<FIG> illustrates a perspective view of the diaphragm <NUM>. As discussed above, the diaphragm <NUM> includes a flexible member 100a, a lip member 100b and a tab 100c. Preferably, the upper surface 102a of the flexible member 100a is a substantially smooth wall portion <NUM> having a constant radius of curvature. For example, the upper surface 102a can be a semi-spherical bowl. Preferably, the wall portion <NUM> of flexible member 100a, is elastic enough to conform to the profile of the inner surface <NUM> of the cover portion 12a (see <FIG>). Preferably, the flexible member 100a conforms to at least a portion of the inner surface <NUM> of the cover portion 12a. In some embodiments, the flexible member 100a conforms to substantially the entire inner surface <NUM> of the cover portion 12a. In some embodiments, the substantially smooth wall portion <NUM> extends to the bottom center of the upper surface 102a. However, in other exemplary embodiments, e.g., as illustrated in <FIG>, the substantially smooth wall portion <NUM> extends part way and circumscribes a central portion <NUM>. As best seen in <FIG> and <FIG>, preferably, a thickness of the central portion <NUM> increases in a radial direction from the substantially smooth wall portion <NUM> to the center of flexible member 101a such that the upper surface 102a is substantially flat along the central portion <NUM>. Preferably, a transition portion 105a provides a tapered transition from the substantially smooth wall portion <NUM> to the central portion <NUM>. Although thicker than the substantially smooth wall portion <NUM>, the central portion <NUM> is still elastic enough to conform to at least a portion of the inner surface <NUM> of cover portion 12a when the diaphragm <NUM> is in the inverted position. Thus, when the flexible member 100a is forced into the inverted position, the upper surface 102a of the flexible member 100a conforms to the profile of the inner surface <NUM> of the cover portion 12a. Preferably, the flexible member 100a conforms to substantially the entirety of the inner surface <NUM>, which provides support for the flexible member 100a. In contrast, known diaphragms do not conform to the inner surface of the cover. Thus, known diaphragms must be made to withstand the full force of the fluid flow and pressure in the valve, which creates stress concentrations in the diaphragm. In exemplary embodiments, the cover portion 12a provides support to the flexible member 100a and thus the flexible member 100a does not have the stress concentrations experienced by known diaphragms. This means that exemplary embodiments of the diaphragm <NUM> of the present disclosure can be more flexible than known diaphragms. In prior art and related art valves, any internal tension force within known diaphragms, by itself, is not enough to urge the diaphragm to the lower position due to its rigidity. However, by making the diaphragm more flexible, the tension force within the diaphragm <NUM> is enough to urge the diaphragm <NUM> back to the seat member <NUM> without requiring an additional bias force from elements and devices such as, e.g., ribs, rings and springs. In addition, by conforming to the inner surface <NUM> of the cover portion 12a, the flexible member 100a maximizes the cross-sectional area of the passageway between the inlet <NUM> and the outlet <NUM>. Thus, the control valves can be made smaller as compared to similarly rated prior art and related art valves.

<FIG> show additional features of the illustrative embodiment of the diaphragm <NUM>. The diaphragm <NUM> includes an upper surface 102a and a lower surface 104a. Each of the upper and lower surface areas 102a, 104a are generally sufficient in size to seal off communication of the inlet and outlet sub-chamber 24a, 24b from the diaphragm sub-chamber 24c (see <FIG>). The geometries of the upper and lower surface areas 102a, 104a are such that the surfaces effectively dissect and seal the chamber <NUM>. Preferably, as seen in the plan views of <FIG> and <FIG>, the upper and lower surface areas 102a, 104a are preferably substantially circular.

The lower surface 104a of the flexible member 100a preferably presents a substantially convex surface, and more preferably a spherical convex surface having an area AA1, and the upper surface 102a of the flexible member 100a presents a substantially concave surface, and more preferably a spherically concave surface having an area AA2. Upper surface AA2 is preferably about equal to AA1. Portions of the lower surface 104a act to seal off fluid communication from the other chambers, i.e. a portion of lower surface 104a seals the inlet sub-chamber 24a from the outlet sub-chamber 24b. The preferred geometry of the sub-chambers 24a, 24b, 24c relative to one another preferably provides that the areas sealing the inlet and outlet sub-chambers 24a, 24b are about equal, and that the inlet sub-chamber 24a is sealed off by a portion of the lower surface 104a having an area of about ½ AA1, and the outlet chamber is sealed off by a portion of the lower surface 104a having an area of about ½ AA1. In one preferred embodiment of the diaphragm <NUM>, the upper surface 102a defines a radius of curvature r1 and the lower surface 104a defines a radius of curvature r<NUM>. Preferably, a ratio of the radii of curvatures between the lower surface 104a r<NUM> and the upper surface 102a r<NUM> (r<NUM>/r<NUM>) is in a range of <NUM> to <NUM>. Where the diaphragm <NUM> includes a middle layer <NUM>, the middle layer <NUM> can further define a third radius of curvature r<NUM>, which is between r<NUM> and r<NUM>. The various radii of curvatures can be measured from a common central point. The ratio of the radius of curvature of a lower surface 104a to the radius of curvature of an upper surface 102a is preferably sufficient to permit the lower surface 104a to engage the seat member <NUM> of bridge element <NUM> when the diaphragm <NUM> is in the lower position and adequately seal off the inlet and outlet sub-chambers 24a, 24b. Preferably, a thickness of the flexible member 100a can be in a range of <NUM> (<NUM> inch) to <NUM> (<NUM> inch) and, more preferably, in a range of <NUM> (<NUM> inch) to <NUM> (<NUM> inch).

Preferably, the radius of curvature r<NUM> of the lower surface 104a and a radius of curvature r<NUM> of the seat member <NUM> of the bridge element <NUM> (see <FIG>) are corresponding radius of curvatures such that the flexible member 100a conforms to and seals against the elongated seat member <NUM> when the flexible member 100a is in the non-inverted position (lower position). Preferably, the lower surface 104a of the flexible member 100a further includes at least one elongated sealing member or projection <NUM> to aid in forming a sealed engagement between flexible member 100a and the seat member <NUM> of the bridge element <NUM>. Preferably, as shown in <FIG>, the diaphragm <NUM> includes a pair of elongated sealing members or projections 114a, 114b. Each of the elongated sealing members 114a, 114b further aids in forming the sealed engagement between flexible member 100a and the seat member <NUM> of the bridge element <NUM>. The sealing members 114a, 114b preferably extend in a parallel fashion along the lower surface 104a for a length about equivalent to the maximum arc length defined by the surface 104a. The elongated sealing members 114a, 114b each have a geometric profile that provides a sealing function and can have a profile such as, e.g., a semicircular cross-sectional profile, a semi-ellipse cross-sectional profile, a semi-oval shape cross-sectional profile, or any other cross-sectional profile that provides the sealing function discussed herein. Preferably, as seen in <FIG>, each of the elongated sealing members 114a, 114b preferably defines a protruding cross-sectional area having a radius of curvature r<NUM> in a range of about <NUM> (<NUM> inch) to <NUM> (<NUM> inch) with tangents of the sidewalls at the interface to the lower surface 104a forming an angle Θ in a range of <NUM> degrees <NUM> degrees. A height h of the elongated sealing members 114a, 114b is in a range of <NUM> (<NUM> inch) to <NUM> (<NUM> inch).

As seen in <FIG>, the sealing members 114a, 114b are preferably spaced apart so as to define a void or channel <NUM> therebetween. The sealing members 114a, 114b along with a portion of the lower surface 104a disposed therebetween further define the sidewalls of the void or channel <NUM> and its channel height The sealing members 114a, 114b are configured to engage the seat member <NUM> of the bridge element <NUM> when the diaphragm is in the closed position so as to seal off communication between the inlet <NUM> and the outlet <NUM> and more specifically seal off communication between the inlet sub-chamber 24a and the outlet sub-chamber 24b. Preferably, in some embodiments, the sealing members 114a, 114b engage the seat member such that the channel <NUM> cooperates with the seat member <NUM> to form an intermediate chamber 24d to axially space the inlet sub-chamber 24a and the outlet sub-chamber 24b in a manner described in greater detail herein below. Although the exemplary embodiment is described with two sealing members, 114a, 114b, the lower surface 104a of the diaphragm <NUM> can include just one sealing element or more than two sealing elements provided that each sealing element cooperates with the seat member <NUM> in a sealing fashion.

<FIG> shows a perspective view of the body portion 12b. The inner surface <NUM> of the body portion 12b includes a bridge element <NUM>. The bridge element <NUM> includes a valve seat member <NUM>. As seen in <FIG>, the body portion 12b preferably defines a valve axis IVB-IVB. The inlet and outlet <NUM>, <NUM> of the control valve <NUM> are preferably centered about, coaxial with and spaced apart along the valve axis IVB-IVB. The body portion 12b further preferably defines an axis IVC-IVC which is substantially orthogonal to the axis IVB-IVB. Preferably aligned with the axis IVC-IVC is the bridge element <NUM> extending the width of the body portion 12b so as to effectively divide the chamber <NUM> in the body portion 12b into the preferably spaced apart and preferably equal sized sub-chambers, e.g., the inlet sub-chamber 24a and the outlet sub-chamber 24b. The body portion 12b also includes one or more support members 28a,b that are respectively connected to each side of the bridge element <NUM>. The support members 28a,b preferably extend f om the flanges of the inlet and outlet <NUM>, <NUM> to intersect the bridge element <NUM>. The support members 28a,b are disposed in a direction mat is substantially parallel to the first axis IVB-IVB, i.e., perpendicular to the bridge element <NUM>. Preferably, each side of the bridge element <NUM> can have a plurality of support members 28a,b, with the number of support members 28a,b being based on the size of the valve <NUM> and/or the pressure rating of the valve <NUM>. Preferably, the bridge element <NUM> has <NUM> to <NUM> support member 28a,b, more preferably <NUM> to <NUM> support member 28a,b, and even more preferably <NUM> to <NUM> support members 28a,b. In the exemplary embodiment of <FIG>, there are five support members 28a,b on the respective sides of bridge element <NUM>. Of course, exemplary embodiments can have fewer than three or more than eleven depending on design criteria such as pressure drop across the valve <NUM>. In addition, the number of support members 28a,b on each side need not be the same. For example, the body portion 12b can have five support members 28b and only three support members 28a or some other combination depending on the needs of the system. The support members 28a,b preferably form a unitary construction with the bridge element <NUM> and the rest of the body portion 12b, or alternatively, the support members 28a,b can be joined to the bridge element <NUM> and the body portion 12b by other joining techniques such as, for example, welding.

The surface of the seat member <NUM> of bridge element <NUM> preferably defines an arc having an arc length to mirror the convex surface of the lower surface 104a of the diaphragm <NUM>. For example, the radius r<NUM> (see <FIG>) and the radius r<NUM> (see <FIG>) are corresponding radius of curvatures. In addition, the arc length corresponding to the surface of seat member <NUM> is substantially equal to the arc length corresponding to the lower surface 104a of flexible member 100a. Further, the surface of each of the support members 28a,b preferably defines an arc that mirrors the convex surface of the lower surface 104a of the flexible member 100a. For example, the radius r<NUM> (see <FIG>) corresponding to the surface of each support member <NUM> and the radius r<NUM> (see <FIG>) corresponding to the lower surface 104a of flexible member 100a are corresponding radius of curvatures. By having the radii r<NUM>, r<NUM> substantially match the radius r<NUM>, the spherical surface profile of the combined structure of the support members 28a,b and bridge element <NUM> substantially matches the profile of the lower surface 104a. Thus, the load from the lower surface 104a when the diaphragm <NUM> is in the lower position will be spread substantially evenly over an area formed by the surfaces of support members 28a, b and the surface of bridge element <NUM>. By spreading the load, the stress concentrations in the flexible member 100a are minimized when the flexible member 100a is in the closed position. In some prior art and related art systems, support members do not exist or are offset from the valve seat such that the support members and the valve seat are not on the same spherical surface. This means that the diaphragm must be designed to handle the load created by the pressure chamber with little or no support from additional valve structures. This leads to a more rigid diaphragm construction and the associated problems discussed above. In exemplary embodiments of the present disclosure, the support members 28a,b and bridge element <NUM> provide support such that the flexible member 100a can be more elastic. As discussed above, a more elastic flexible member 100a allows for a diaphragm configuration in which basing elements such as ribs and springs can be eliminated.

Preferably, in some embodiments, extending along the preferred arc length of the bridge element <NUM> is a groove or channel <NUM> constructed or formed in the surface of the seat member <NUM>. The groove <NUM> preferably extends the full length of the seat member <NUM> so as to extend the width of the body portion 12b. Furthermore, the groove <NUM> preferably tapers narrowly at its ends. In addition, the walls of the seat member <NUM> that define the groove <NUM> are preferably parallel. Alternatively, the groove <NUM> can be formed such that the walls forming the groove <NUM> are angled relative to one another, another reference line or other surface in the valve body <NUM>. The bottom of the groove <NUM> preferably forms a semi-circular arc in the plane perpendicular to the direction of elongation for the groove <NUM>. Other geometries are possible provided the channel <NUM> delivers the desired fluid and hydraulic characteristics for the appropriate exemplary embodiments as described herein. Moreover, the depth of the groove <NUM> can vary along its length such that the groove <NUM> is preferably deepest at its center and becomes more shallow toward its lateral ends. The groove <NUM> farther bisects the engagement surface of the seat member <NUM> preferably evenly along the seat member length. When the diaphragm member <NUM> is in the closed positioned, the elongated sealing members 114a, 114b are preferably aligned to engage the bisected surface of the seat members <NUM>. Preferably, engagement of the sealing members 114a, 114b with the engagement surfaces 26a, 26b of the seat member <NUM> further places the channel <NUM> of the diaphragm <NUM> in communication with the groove <NUM>.

As seen in <FIG>, preferably, the engagement surfaces 26a, 26b of the seat member <NUM> are substantially planar. Generally, the surfaces 26a, 26b are configured sufficiently wide over their entire length so as to maintain sealing contact with the lower surface 104a of flexible member 100a. Preferably, the surfaces 26a, 26b are configured wide enough so as to maintain sealing contact with sealing members 114a, 114b regardless of any movement of the sealing members 114a, 114b along the longitudinal axis IVB-IVB. Accordingly, the surfaces 26a, 26b can maintain sealed engagement with the lower surface 104a, which preferably includes sealing members 114a, 114b, despite changes in fluid pressure in either the inlet or outlet sub-chamber 24a, 24b which can impose forces on the flexible member 100a and sealing members 114a, 114b in a direction along the axis IVB-IVB.

As seen in <FIG>, the bridge element <NUM> is preferably formed with a central base member <NUM> mat further separates and preferably spaces the inlet and outlet sub-chambers 24a, 24b and diverts fluid in a direction between the diaphragm <NUM> and the seat member engagement surfaces 26a, 26b. As seen, for example, in <FIG> and <FIG>, the base member <NUM> is preferably broader in the direction along the axis IVB-IVB than along the axis IVC-IVC. The base member <NUM> is preferably substantially aligned with the central axis B-B of the valve body <NUM> which intersects substantially orthogonally the plane formed by the intersection of the axis IVB-IVB and the axis JVC-JVC. In some embodiments, a port <NUM> is formed in the base member <NUM> between inlet sub-chamber 24a and outlet sub-chamber 24b. The drain <NUM> diverts the first fluid, water from a water main, entering the valve <NUM> through the inlet <NUM> to outside the valve body <NUM>. The input opening <NUM> can be used to introduce the second fluid, e.g., compressed gas, into the valve body <NUM> for discharge out the outlet <NUM>.

The port <NUM> is preferably constructed as an alarm port from one or more voids formed in the base member <NUM>. The port <NUM> preferably extends substantially perpendicular to a central axis B-B so as to intersect and be in communication with a channel that extends to the groove <NUM>. After the port <NUM> is constructed, the channel can be plugged using plug SO. Accordingly, when the diaphragm member <NUM> is in the closed position, the port <NUM> is further preferably in sealed communication with the channel <NUM> formed in the diaphragm member <NUM>. Alternatively or in addition to the port <NUM>, in some embodiments, the plug SO can be removed and the channel can be used as an alarm port.

The communication between the diaphragm channel <NUM>, the groove <NUM> and the port <NUM> is preferably bound by the sealed engagement of the sealing members 114a, 114b with the seat member surfaces 26a, 26b, to thereby define a preferred fourth chamber, intermediate chamber 24d, as seen, for example, in <FIG>. The intermediate chamber 24d is preferably open to atmosphere thereby further defining a fluid seat, preferably an air seat, to separate the inlet and outlet sub-chambers 24a, 24b. Providing an air seat between the inlet and outlet sub-chambers 24a, 24b allows each of the inlet and outlet chambers to be filled and pressurized while avoiding failure of the sealed engagement between the sealing member <NUM> and the seat member <NUM>. Because each sealing member <NUM> is acted upon by a fluid force on only one side of the element and preferably atmospheric pressure on the other, the fluid pressure in the diaphragm sub-chamber 24c is effective to maintain the sealed engagement between the sealing member <NUM> and the seat member <NUM> during pressurization of the inlet and outlet sub-chambers 24a, 24b.

<FIG> is a perspective view of the cover portion 12a. The cover portion 12a includes a dome section <NUM> and a flange section <NUM>. Preferably, the flange section <NUM> includes a plurality of bolt holes <NUM> to receive bolts <NUM> or threaded studs 29a (see <FIG>). The threaded studs 29a facilitate the assembly of the cover portion 12a when the valve <NUM> is mounted in a vertical position. For example, the cover portion 12a can be hung on the threaded studs 29a while the bolts <NUM> are inserted in the remainder of the holes <NUM>. The cover portion 12a and the body portion 12b are preferably coupled together by a plurality of bolts distributed in a bolt pattern about the body <NUM>. A preferred bolt pattern includes eight bolt/nut assemblies. In an alternative bolt assembly, a threaded stud assembly or a combination of both bolts and threaded studs can be utilized. Preferably, the bolt or threaded stud pattern is disposed on the valve body <NUM> such that the bolts do not penetrate diaphragm <NUM>. That is, the bolts and/or threaded studs are disposed outside the outer perimeter of diaphragm <NUM> as seen in <FIG>.

As seen in <FIG>, an inside surface <NUM> of the cover portion 12a has a dome-shaped profile that permits the flexible member 100a to conform to the inside surface <NUM>. Preferably, the dome-shaped profile has a radius r<NUM> with respect to a point on the centerline of the cover portion 12a. Preferably, the dome-shaped profile extends to the edge <NUM> (see dotted line in <FIG>) of the cover portion 12a at the interface to the diaphragm <NUM>. By extending the dome-shaped profile to the edge <NUM>, the cover portion 12a does not prevent the flexible member 100a from fully inverting, e.g., does not prevent the flexible member 100a from reaching its natural-inverted position.

However, in some embodiments, as seen in <FIG>, the dome-shaped profile is limited to a central section <NUM> of the cover portion 12a and an inversion inhibitor <NUM> extends from the cover portion 12a, near the edge <NUM>. The inversion inhibitor <NUM> prevents the flexible member 100a from reaching its natural-inverted position by blocking the flexible member 100a. Although the flexible member 100a can conform to the inner surface <NUM> of the cover portion 12a, including the inversion inhibitor <NUM>, the flexible member 100a does not fully invert (e.g., does not reach its natural-inverted position) as in a case where the cover portion 12a does not include an inversion inhibitor <NUM>. By blocking the full inversion of the flexible member 100a, the inversion inhibitor <NUM> creates a tension force within the flexible member 100a that urges the flexible member 100a to the seat member <NUM>.

As seen in <FIG>, when compared to the surface profile of central section <NUM>, the surface profile of the inversion inhibitor <NUM>, which circumscribes the central section <NUM>, projects into the chamber <NUM> toward the central axis of the cover portion 12a. The projection into the chamber <NUM> by the inversion inhibitor <NUM> blocks the full inversion of the flexible member 100a. The inversion inhibitor <NUM> can be, for example, a bulge or protruding section on the inner surface of the chamber <NUM>. Preferably, as shown in <FIG>, the inversion inhibitor <NUM> is a deviation of the inner surface <NUM> from a surface curvature defined by radius r7(see deviation from dotted line in <FIG>. Preferably, deviation of the inner surface <NUM> is greatest near the edge <NUM> adjacent to the diaphragm <NUM> when the control valve <NUM> is assembled and the deviation gradually decreases to zero, i.e., the inner surface profile matches the surface profile corresponding to the radius r<NUM>, in a direction towards the central section <NUM>. Preferably, a maximum thickness t" of the inversion inhibitor <NUM>, as measured in a radial direction from the surface of the inversion inhibitor <NUM> towards a surface corresponding to radius r<NUM>, is in a range of <NUM> (<NUM> inch) to <NUM> (<NUM> inch). Preferably, the inversion inhibitor <NUM> has a length L that is in a range of <NUM> (<NUM> inch) to <NUM> (<NUM> inch) as projected on a plane that is perpendicular to the radius r7 at the maximum thickness t" of the inversion inhibitor <NUM>.

In some embodiments, the inversion inhibitor <NUM> defines a substantially rounded cross-sectional profile. For example, the cross-sectional profile can be a substantially semicircular profile, substantially a semielliptical profile with respect to a major axis or a minor axis, a substantially triangular-shaped profile, or any other profile that can provide a bias force on the flexible member 100a to urge or aid in urging the flexible member 100a to the seat member <NUM>. Preferably, as seen in <FIG>, the inversion inhibitor <NUM> at edge <NUM> adjacent to the diaphragm <NUM> is curved such that the cross-sectional profile is substantially a semi-tear drop shaped profile. In the direction from the central section <NUM> to the edge <NUM>, the tear-drop profile provides for a gradual increase in the deviation of the inner surface <NUM> from the line corresponding to radius r<NUM>. By gradually increasing the deviation, the flexible member 100a can still conform to the inner surface <NUM> of cover portion 12a when the flexible member 100a is in the inverted position, m some embodiments, along with the tension force in the layer <NUM> of diaphragm <NUM>, the inversion inhibitor <NUM> can create a tension force within the flexible member 100a to aid in urging the flexible member 100a to the seat member <NUM> as discussed above.

As discussed above, lip element 100b of diaphragm <NUM> circumscribes the flexible member 100a. As seen in <FIG> and <FIG>, preferably, the cover portion 12a and the body portion 12b each include a channel <NUM>, <NUM>, respectively, that circumscribes the chamber <NUM>. When the cover portion 12a and the body portion 12b are joined together, the channels <NUM> and <NUM> define a cavity <NUM> (see <FIG>) for receiving the lip member 100b. Each channel <NUM>, <NUM> includes an outer radial wall 36a, 37a, respectively, and an inner radial wall 36b, 37b, respectively. The inner radials walls 36b, 37b are shorter in length than the outer radial walls 36a, 37a, respectively, such that when assembled, a gap is formed that provides a passage from the cavity <NUM> to the chamber <NUM>. In the embodiments of <FIG> and <FIG>, the channels <NUM> and <NUM> have profiles that are substantially square but with the inner radial walls 36b and 37b disposed at a slight angle with respect to a normal to the channel base 36c, 37c. In other embodiments, for example, as seen in <FIG> and <FIG>, the channels <NUM>' and <NUM>' have profiles that are substantially trapezoidal in shape with both the outer radial walls 36a', 37a' and the inner radial walls 36b', 37b' are at an angle with respect to a normal to the channel base 36c', 37c'. The shape and dimensions of the channels will depend on the pressure rating of the valve <NUM> and/or the geometry of the valve <NUM>. For example, the channel shape and dimension can be configured to limit any obstruction to the inlet <NUM> and outlet <NUM> of valve <NUM>. Preferably, the shapes and dimensions of the corresponding channels between the cover portion 12a and the body portion 12b are substantially the same, for example, as seen in <FIG> and <FIG>. However, in some embodiments the shapes and dimensions can be different. For example, as seen in <FIG> and <FIG>, the base of channel 36c' is narrower than the base of channel 37c'.

The diaphragm <NUM> is disposed between the cover portion 12a and the body portion 12b. When the control valve <NUM> is assembled, the cavity <NUM> engages the lip member 100b of the diaphragm <NUM> such that the channel <NUM> of cover portion 12a and the channel <NUM> of the body portion 12b pinch the lip member 100b to securely hold the diaphragm <NUM>. Because the lip member 100b is secured, when the flexible member 100a is inverted as discussed above, a tension force is created in layer <NUM> of the diaphragm <NUM>.

In preferred embodiments, the diameter of the circle defining cavity <NUM> is smaller than the diameter of the circle defining the bolt pattern for bolts <NUM> and/or threaded studs 29a. In this way, the bolts <NUM> and/or threaded studs 29a are disposed on the valve body <NUM> such that the bolts/threaded studs do not penetrate diaphragm <NUM>. That is, the bolts and/or threaded studs are disposed outside the outer perimeter of lip member 100b of diaphragm <NUM> as seen in <FIG>. By disposing the bolts threaded studs outside the circumference of diaphragm <NUM>, the diaphragm <NUM> in preferred embodiments does not have any holes and thus does not experience the high stress concentrations that known diaphragms (in which the bolts go through the diaphragm) experience around the holes during the open/close cycles of the valve.

Preferably, the lip element 100b forms a seal between the chamber <NUM> and the outside atmosphere mat can withstand the operating pressure of the control valve <NUM> when the valve <NUM> is assembled and in operation. The cross-sectional profile of the lip element 100b can be a semicircle-shaped cross-section, an elliptical-shaped cross-section or any other cross-sectional profile so long as the lip member 100b provides the requisite seal. For example, <FIG> illustrate a preferred configuration of the lip member 100b. The lip member 100b is received by the cavity <NUM>. The lip member 100b preferably has a substantially oval-shaped cross-section <NUM>. Preferably, the oval-shaped cross-section <NUM> has a flattened profile on a side adjacent to the flexible member 100a. The oval-shaped cross-section <NUM> includes two endpoints 41a, 41b that respectively engage the upper surface <NUM> of the cover portion 12a in channel <NUM> and the lower surface <NUM> of the body portion 12b in channel <NUM>. Preferably, the thickness t of the lip member 100b is in a range of <NUM> inch (<NUM>) to <NUM> inches (<NUM>), and more preferably <NUM> inch (<NUM>) to <NUM> inches (<NUM>). When secured, the two endpoints, which are composed of a rubber or elastic material, are pinched in the cavity <NUM> and deformed so as to seal the control valve <NUM>.

In another exemplary embodiment, for example, as seen in <FIG>, a preferred configuration of the lip member 100b' has substantially a rectangular-shaped cross-section <NUM>'. Preferably, the rectangular-shaped cross-section <NUM>' includes two ends 41a', 41b' that respectively engage the upper surface <NUM> of the cover portion 12a of channel <NUM>' and the lower surface <NUM> of the body portion 12b of channel <NUM>'. Preferably, the thickness t' of the lip member 100b' is in a range of <NUM> (<NUM> inch) to <NUM> (<NUM> inches), and more preferably <NUM> (<NUM> inch) to <NUM> (<NUM> inches). When secured, the two ends, which are composed of a rubber or elastic material, are pinched in the cavity formed by channels <NUM>', <NUM>' and deformed so as to seal the control valve <NUM>.

Preferably, the lip member 100b, 100b' is composed of a material that is not compressible. Preferably, the lip member 100b, 100b' has the same material composition as the rest of diaphragm <NUM>. By disposing the lip member 100b, 100b' between two channels <NUM>, <NUM> or <NUM>', <NUM>' in preferred embodiments as discussed above, minor flaws and imperfections in the flanges or the diaphragm will not prevent the lip member 100b, 100b' from sealing the valve <NUM>.

As seen in <FIG> and <FIG> a transition portion from the respective lip members 100b, 100b' to the flexible member 100a includes an upper curvilinear path <NUM> corresponding to the upper surface 102a and a lower curvilinear path <NUM> corresponding to the lower surface 104a. The transition portion is disposed in the gap between the respective inner radial walls, i.e., 36b and 37b or 36b' and 37b'. Preferably, the upper curvilinear path <NUM> has a tighter curved path than the lower curvilinear path <NUM>. The upper and lower curvilinear paths <NUM>, <NUM> preferably transition to the flexible member 100a at substantially a mid-point of the side of the respective lip member 100b, 100b'.

Turning to <FIG>, the control valve <NUM> can be placed into service by preferably bringing the valve <NUM> to the normally closed position and subsequently bringing the inlet sub-chamber 24a and the outlet sub-chamber 24b to operating pressure. In one preferred installation, the first fluid source is initially isolated from the inlet sub-chamber 24a by way of a shut-off control valve such as, for example, a manual control valve located upstream from the inlet <NUM>. The second fluid source is preferably initially isolated from the outlet sub-chamber 24b by way of a shut-off control valve located upstream from the input opening <NUM>. If the pressures in sub-chambers 24a and 24c are already equalized at this point, e.g. the pressures PI, P2, P3 are equal, the tension force within the diaphragm <NUM> and, in some embodiments, aided by the additional tension force created by the inversion inhibitor <NUM>, will urge the flexible member 100a from the inverted position to the closed position as discussed above. If not, for example P2 and P3 are greater than PI, the following steps will place the control valve <NUM> in a state ready for operation. An equalizing fluid, such as water from the first fluid source is then preferably introduced into the diaphragm sub-chamber 24c through the central opening <NUM> in the cover portion 12a. Fluid is continuously introduced into the sub-chamber 24c until the fluid exerts enough pressure PI to bring the flexible member 100a to the closed position in which the lower surface 104a engages the bridge element <NUM>. In the closed position, the lower surface 104a of flexible member 100a, which in some embodiments includes the sealing members 114a, 114b, forms a sealed engagement about the seat member <NUM>.

With the diaphragm member <NUM> in the closed position, the inlet and outlet sub-chambers 24a, 24b can be pressurized respectively by the first and second fluids. More specifically, the shut-off valve isolating the first fluid, e.g., water from a water main, can be opened so as to introduce the first fluid through the inlet <NUM> and into the inlet sub-chamber 24a to preferably achieve a static pressure P2. The shut-off valve isolating the second fluid, e.g., the compressed gas, can be opened to introduce the second fluid through the input opening <NUM> to pressurize the outlet sub-chamber 24b and the normally closed system, e.g., a fire system piping network, coupled to the outlet <NUM> of the control valve <NUM> to achieve a static pressure P3.

As described above, the intermediate chamber 24d is disposed between the inlet and outlet sub-chambers 24a, 24b and is normally open to atmosphere. The primary fluid pressure P2 is isolated from chamber 24d by the sealing member 114a and the secondary fluid pressure P3 is isolated from chamber 24d by the sealing member 114b. Thus, diaphragm member <NUM>, and in some embodiments its sealing members 114a, 114b, is configured so as to maintain the sealed engagement with the seat member <NUM> under the influence of the diaphragm chamber pressure PI. Accordingly, when in the closed position, the upper and lower diaphragm surface areas Al, A2, and A3 are preferably sized such that the force provided by pressure PI is large enough to overcome the forces provided by primary and secondary fluid pressures P2, P3 urging the diaphragm member <NUM> to the open position. However, the upper and lower diaphragm surface areas Al, A2, and A3 are also sized to provide a fast opening response. Because the flexible member 100a is not as rigid as prior art and related art diaphragms, the valve <NUM> has a faster opening response than such diaphragms when fluid is released from the inlet chamber. In addition, the pressure drop due to the diaphragm and/or biasing devices such as ribs and springs is also minimized.

Claim 1:
A fluid control valve (<NUM>) comprising:
a cover portion (12a) with a first inner surface and a first channel (<NUM>), the first channel (<NUM>) including a first radial outer wall (36a) and a first radial inner wall (36b) shorter in length than the first radial outer wall (36a);
a body portion (12b) secured to the cover portion (12a), the body portion (12b) having a second inner surface and a second channel (<NUM>), the second channel (<NUM>) including a second radial outer wall (37a) and a second radial inner wall (37b) shorter in length than the second radial outer wall (37a), the first and second inner surfaces defining a chamber (<NUM>), the first channel (<NUM>) and the second channel (<NUM>) circumscribing the chamber (<NUM>), a gap formed to provide a passage from a cavity (<NUM>), which is defined by the first radial outer wall (36a), the first radial inner wall (36b), the second radial outer wall (37a), and the second radial inner wall (37b), to the chamber (<NUM>); and
a diaphragm (<NUM>) disposed between the cover portion (12a) and the body portion (12b), the diaphragm (<NUM>) including a flexible member (100a) disposed in the chamber (<NUM>), a lip member (100b) circumscribing the flexible member (100a) and a tab (100c), an upper surface (102a) of the flexible member (100a) including a substantially smooth wall portion (<NUM>) having a constant radius of curvature which extends part way and circumscribes a central portion (<NUM>), wherein a thickness of the central portion (<NUM>) increases in a radial direction from the substantially smooth wall portion (<NUM>) to the centre of flexible member (100a) such that the upper surface (102a) is substantially flat along the central portion (<NUM>),
wherein the first channel (<NUM>) and the second channel (<NUM>) define the cavity (<NUM>) that circumscribes the chamber (<NUM>) and each channel (<NUM>,<NUM>) receives a portion of the lip member (100b) and pinches the lip member (100b) to seal the fluid control valve (<NUM>) and hold the diaphragm (<NUM>).