Pulse-clearing diaphragm valve and related methods

Abstract

A diaphragm valve for gas analysis applications is provided. The valve includes: a valve bonnet having a plurality of process conduits extending therethrough; a valve body engageable with the valve bonnet and having a body-engaging portion with a recess; a diaphragm positioned between the valve bonnet and the valve body and having a process groove for circulating a fluid therein, the process groove engaging the recess; a plunger assembly disposed within the valve body, the plunger assembly including a plurality of plungers movable between a closed position in which the plungers engage the diaphragms and an open position in which the plungers are spaced from the diaphragms; and an actuating assembly including a gas inlet for allowing injection of an actuating gas therein, the actuating assembly including a purging system for purging an area between the diaphragm and the body-engaging portion, thereby purging the area with the actuating gas.

Description

Technical Field

[0001] TECHNICAL FIELD

[0002] The present invention relates generally to valve-related systems and methods, and more particularly to purge systems for diaphragm-sealed valves, such as valves used in gas analysis and / or gas chromatography applications. Background Art

[0002] In a diaphragm valve, communication between ports is prevented or permitted by pushing a plunger against or retracting it from the diaphragm, which is typically made of a soft / deformable material. Diaphragm valves may be equipped with a purge system that injects a purge gas into selected areas of the valve to remove impurities from those areas. The area beneath the diaphragm is particularly important for purging. Because the diaphragm has a certain degree of porosity, gas molecules / atoms may leak through the diaphragm and contaminate the valve.

[0003] Existing purging systems typically require purge inlets, outlets, piping, fittings, and / or conduits to reach the desired area and effectively purge the valve. This additional hardware to operate the valve increases labor costs to produce the valve, cabinet space required for various components, and ultimately, the price of the valve. Furthermore, operating costs of the valve increase because a constant / continuous flow of purge gas is injected into the valve to ensure a clean environment within.

[0004] In view of the above, there is a need for an improved valve having a simpler and more efficient purge system.There is also a need for a valve that is easier to manufacture and that will allow the disadvantages associated with the difficulty of operating a continuous purge system to be overcome. Summary of the Invention

[0005] According to a first aspect, a diaphragm valve for gas analysis applications is provided. The valve comprises a bonnet having a plurality of process conduits extending therethrough, the bonnet having a bonnet engagement portion, and each of the process conduits including a process port opening into the bonnet engagement portion. The valve further comprises a valve body engageable with the bonnet and having a body engagement portion adapted to face the bonnet engagement portion and provided with a recess, the valve body including a plurality of plunger channels extending through the valve body, whereby the plunger channels open into the recess. A diaphragm is positioned between the bonnet and the valve body and has a process groove for circulating a fluid in the diaphragm, the process groove being shaped and dimensioned to engage with the recess of the valve body. The valve also includes a plunger assembly disposed within the valve body, the plunger assembly including a plurality of plungers slidably mounted within corresponding ones of the plunger passages, each plunger being movable between a closed position, in which the plunger engages the diaphragm and prevents fluid circulation between the two process ports along the process tank, and an open position, in which the plunger is spaced from the diaphragm, thereby permitting fluid circulation along the process tank. The valve also includes an actuation assembly having a gas inlet extending through the valve body to permit injection of an actuating gas to move the plunger between the open and closed positions, and a purge system for purging a purge region located between the diaphragm and the body, wherein the actuating gas is used to purge the purge region.

[0006] According to a possible embodiment, the valve further comprises a bottom cover connected to the valve body and defining an inner cavity with the valve body, wherein the plunger assembly comprises an upper piston operatively engaged with the first group of plungers and a lower piston engaged with the second group of plungers, the upper piston and the lower piston being disposed within the inner cavity, whereby the inner cavity is in fluid communication with the clearing area via the plunger channel.

[0007] According to a possible embodiment, the first group of plungers are normally open plungers, while the second group of plungers are normally closed plungers.

[0008] According to a possible embodiment, the inner cavity includes a top area located between the upper piston and the plurality of plunger channels, a bottom area located between the lower piston and the bottom cover, and an intermediate area located between the upper piston and the lower piston, and wherein the gas inlet is positioned to allow actuating gas to be injected into the intermediate area for actuating at least one of the upper piston and the lower piston.

[0009] According to a possible embodiment, the cleaning system comprises a controlled flow channel adapted to establish fluid communication between the middle zone and the top zone.

[0010] According to a possible embodiment, the controlled flow channel comprises a first flow restrictor adapted to restrict the flow of fluid through the controlled flow channel in order to generate a pressure in the intermediate region.

[0011] According to a possible embodiment, the first flow restrictor is a first non-return valve having a first opening pressure and being configured to allow the fluid to flow therethrough when the pressure in the intermediate region is above the first opening pressure.

[0012] According to a possible embodiment, the controlled flow channel further comprises a flow restrictor having a passage in fluid communication with the outlet of the first check valve, the passage being shaped and dimensioned to restrict a flow rate of the actuating gas from the middle region to the top region.

[0013] According to a possible embodiment, the upper piston comprises a recess, and wherein the flow restrictor comprises a removable insert adapted to engage with the recess of the upper piston, the passage extending through the removable insert.

[0014] According to a possible embodiment, the channel is shaped and dimensioned so as to limit the flow rate between the middle zone and the top zone to about 0.5 cm 3 / min and 2cm 3 / min.

[0015] According to a possible embodiment, the actuation assembly further comprises a gas outlet positioned to establish fluid communication between the inner cavity and the surrounding environment.

[0016] According to a possible embodiment, the gas outlet comprises an outlet flow restrictor adapted to at least partially prevent the gas from leaving the inner cavity, thereby directing the actuating gas to the purge area via the plunger channel.

[0017] According to a possible embodiment, the gas outlet communicates with the top region, and the outlet flow restrictor comprises an outlet check valve having an outlet cracking pressure, the outlet check valve being configured to allow fluid flow therethrough when the pressure in the top region is above the outlet cracking pressure.

[0018] According to a possible embodiment, the outlet opening pressure is greater than the atmospheric pressure of the surroundings of the diaphragm valve.

[0019] According to a possible embodiment, the outlet check valve has a closing pressure which closes the outlet valve, and the pressure in the purge region oscillates between the outlet opening pressure and the closing pressure.

[0020] According to a possible embodiment, the plungers have an outer surface and each plunger includes one or more grooves extending along the respective outer surface between the top end of the plunger and the bottom end of the plunger to promote fluid communication between the top area of ​​the inner cavity and the clearing area.

[0021] According to a possible embodiment, the grooves are helical and / or vertically oriented.

[0022] According to a possible embodiment, the plunger includes a plunger head adapted to engage with the diaphragm, a plunger base adapted to engage with one of the upper piston and the lower piston, and a plunger body extending between the plunger head and the plunger base, wherein the plunger head, plunger base and plunger body of one or more plungers are independent of each other and superimposed in corresponding plunger channels.

[0023] According to a possible embodiment, the plunger head and the plunger base are substantially rigid, and wherein the plunger body is made of a compressible material, an elastomeric material or a combination thereof.

[0024] According to a possible embodiment, the plunger body comprises at least two adjacent parts extending between the plunger head and the plunger base, and wherein the parts have a different compressibility.

[0025] According to a possible embodiment, the plunger body is offset from a central longitudinal axis of the plunger.

[0026] According to a possible embodiment, the plunger base of each plunger is fully seated on a corresponding one of the upper piston and the lower piston.

[0027] According to a possible embodiment, the plunger base of each plunger is connected to a corresponding one of the upper piston and the lower piston in a fixed manner.

[0028] According to a possible embodiment, the upper piston comprises a central hole, a plurality of upper recesses and a plurality of upper protrusions, and the first set of plungers is adapted to sit on the upper protrusions.

[0029] According to a possible embodiment, the lower piston comprises a piston head adapted to extend through the central hole of the upper piston, the lower piston comprising a plurality of lower recesses and lower protrusions, the second set of plungers being adapted to sit on the lower protrusions.

[0030] According to a possible embodiment, the central hole and the piston head are shaped in a complementary manner.

[0031] According to a possible embodiment, the upper protrusion is shaped and configured to engage with the lower recess, and the lower protrusion is shaped and configured to engage with the upper recess.

[0032] According to a possible embodiment, the actuation assembly further comprises an activation system configured to selectively exert a force on the lower piston in order to move the second set of plungers in the closed position.

[0033] According to a possible embodiment, the activation system comprises an actuating screw adapted to exert a force on the lower piston, and the bottom cover comprises a storage mechanism operatively engaged with the actuating screw to indicate the position of the actuating screw.

[0034] According to a possible embodiment, the actuating screw comprises recesses distributed around the outer periphery of the head of the actuating screw, and the storage mechanism comprises a set screw capable of engaging with the recesses of the actuating screw.

[0035] According to another aspect, a method for purging an area between a diaphragm and a valve body of a diaphragm valve is provided. The method includes the steps of injecting an actuating gas into the diaphragm valve via a gas inlet; directing the actuating gas along a purge circuit so that the actuating gas reaches a purge area; pressurizing the purge area; and releasing the actuating gas via a gas outlet to purge the purge area.

[0036] According to a possible embodiment, the gas inlet is in communication with an inner cavity provided in the diaphragm valve, wherein the step of injecting the actuating gas into the diaphragm valve comprises: pressurizing the inner cavity to open the first check valve and allow the actuating gas to flow from the inner cavity to the purge area.

[0037] According to a possible embodiment, the step of directing the actuating gas along the purge circuit comprises blocking the gas outlet before the actuating gas leaves the valve via the gas outlet to force the actuating gas to flow from the inner cavity to the purge area, thereby allowing pressurization of the purge area.

[0038] According to a possible embodiment, the purge circuit is completely defined within the diaphragm valve.

[0039] According to another aspect, a diaphragm valve for gas analysis applications is provided. The valve comprises: a valve bonnet provided with a plurality of process conduits extending through the valve bonnet, the valve bonnet having a bonnet engagement portion, and each of the process conduits comprising a process port opening into the bonnet engagement portion; a valve body engageable with the valve bonnet and having a body engagement portion adapted to face the bonnet engagement portion and provided with a recess, the valve body comprising a plurality of plunger channels extending through the valve body, whereby the plunger channels open into the recess; a diaphragm positioned between the valve bonnet and the valve body and having a process groove for circulating a fluid in the diaphragm, the process groove being shaped and sized to engage with the recess of the valve body; and a plunger assembly adapted to Mounted within a valve body, the plunger assembly includes a plurality of plungers slidably mounted within corresponding ones of the plunger passages, each plunger being adapted to selectively engage with a diaphragm to control fluid circulation along a process tank; and an actuation assembly including an actuation system configured to enable injection of actuating gas into the valve body for actuating the plunger assembly and displacing the plungers, wherein a purge region is defined between the diaphragm and the body engagement portion, and wherein the actuation assembly includes a purge system configured to direct actuating gas to the purge region for purging the purge region and removing impurities therefrom.

[0040] According to another aspect, a diaphragm valve for gas analysis applications is provided. The valve comprises: a valve bonnet provided with a plurality of process conduits extending through the valve bonnet, the valve bonnet having a bonnet engagement portion, and each of the process conduits comprising a process port opening into the bonnet engagement portion; a valve body engageable with the valve bonnet and having a body engagement portion adapted to face the bonnet engagement portion and provided with a recess, the valve body comprising a plurality of plunger channels extending through the valve body, whereby the plunger channels open into the recess; a diaphragm positioned between the valve bonnet and the valve body and having a process groove for circulating a fluid in the diaphragm, the process groove being shaped and sized to engage with the recess of the valve body; and a plunger assembly adapted to be mounted in the valve body, the plunger assembly comprising a plurality of plungers having a plurality of plungers with a piston slidably mounted within a corresponding one of the piston passages, each piston being adapted to selectively engage the diaphragm to control fluid circulation along the process tank; an actuation assembly including a starting system including an actuation screw operably connected to the plunger assembly and operable between an engaged position and a disengaged position in which the diaphragm valve can be operated for gas analysis applications; and a storage mechanism including a set screw engageable with a first portion of the actuation screw for indicating that the actuation screw is in the engaged position and engageable with a second portion of the actuation screw for indicating that the actuation screw is in the disengaged position.

[0041] By reading the exemplary implementation forms of the present invention with reference to the accompanying drawings, other features of the advantages of the present invention will be better understood. It should also be noted that the embodiments of the diaphragm valve described herein are intended to be exemplary only, and the features of one embodiment should not be understood as being exclusive to that particular embodiment, and that combinations and variations of the components described herein are possible and can be used. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a top perspective view of a diaphragm sealing valve according to a possible embodiment.

[0043] Figure 2 yes Figure 1 0026] Figure 2 is a cross-sectional view of a valve showing a pair of pistons disposed within the valve according to an embodiment.

[0044] Figure 3 yes Figure 1 FIG. 1 is a top perspective exploded view of a valve illustrating various components of the valve according to an embodiment.

[0045] Figure 4 yes Figure 1 0015] Figure 1 is a bottom perspective exploded view of a valve illustrating an interior cavity defined in a valve body according to an embodiment.

[0046] Figure 5 yes Figure 4 An enlarged view of a valve cover is shown in FIG, illustrating process ports that open to a surface of the valve cover according to an embodiment.

[0047] Figure 6 yes Figure 3 , illustrating a recess defined on a surface of the valve body and a process groove defined on the diaphragm according to an embodiment.

[0048] Figure 7 and Figure 7A yes Figure 1 0026] A cross-sectional view of a valve showing a plunger extending within a plunger channel and a purge circuit within the valve according to an embodiment.

[0049] Figure 8 is a perspective view of a portion of a plunger assembly according to an embodiment.

[0050] Figure 9 yes Figure 8 An exploded view of a portion of a plunger assembly is shown in FIG, illustrating upper and lower pistons that are at least partially complementarily shaped according to an embodiment.

[0051] Figure 10 yes Figure 9 An exploded view of the upper piston shown in FIG. 1 illustrates a flow restrictor according to an embodiment.

[0052] 11a is a top perspective exploded view of an alternative embodiment of a plunger assembly showing a triangular push plate connectable to a lower piston according to an embodiment.

[0053] 11 b is an exploded bottom perspective view of an alternative embodiment of the plunger assembly shown in FIG. 11 a , illustrating an upper piston having an annular central aperture for receiving a piston head of a lower piston, according to an embodiment.

[0054] Figure 12 is a perspective view of a plurality of plungers seated on the piston shown in FIG. 11 a .

[0055] Figure 13 is an exploded view of an alternative embodiment of a plunger assembly showing an annular piston head engageable within an annular central bore according to an embodiment.

[0056] Figure 14 Is sitting in Figure 13 A perspective view of multiple plungers on a piston shown in FIG.

[0057] Figures 15 to 20 are various embodiments of the plunger.

[0058] Figure 21 is a bottom plan view of a bottom cover of a valve illustrating a storage mechanism according to an embodiment.

[0059] Figure 22 yes Figure 21 , showing a set screw engaged with a compression screw of a valve, according to an embodiment.

[0060] Figure 23A is a graph illustrating pressure changes near an inlet when a valve is actuated and not actuated, according to an embodiment. Figure 23B is a graph illustrating pressure variations within a compartment or region of a valve, according to an embodiment. Figure 23C is a schematic diagram illustrating the main components of the pulse clearing system. Figure 23D is a graph illustrating variations in impurity concentration within compartments or regions of a valve, according to an embodiment.

[0061] Figure 24 and Figure 25 is a cross-sectional view of an alternative embodiment of a valve showing a second path for establishing fluid communication with an external purge area according to a possible embodiment.

[0062] Figure 26 yes Figure 25 , showing a top perspective view of a valve body, illustrating a gas outlet opening onto a body joint according to an embodiment.

[0063] While the invention will be described in conjunction with example embodiments, it will be understood that this is not intended to limit the scope of the invention to these embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as defined in this application. DETAILED DESCRIPTION

[0064] The present invention relates to a valve, and more particularly to a diaphragm sealed valve and an operating method associated with the valve. The diaphragm sealed valve is referred to herein simply as the "valve". The valve includes a number of improvements, each of which can be implemented in the valve independently of each other or in combination. For example, the valve may include an improved purge system that is configured to effectively purge one or more areas positioned around the diaphragm of the valve. The purge system can be configured to produce a cycle of repeated pulses to purge one or more areas of the valve. In possible embodiments, the valve may include a plunger that is configured to facilitate purging of the area around the diaphragm. In other embodiments, the valve may include a storage mechanism to facilitate storage after the valve is closed. The present invention will be better understood through the description of possible embodiments of the valve. Although the different embodiments of the valve described below are embodiments of a diaphragm sealed valve, it should be understood that other types of valves are also possible.

[0065] Broadly refer to Figures 1 to 26 , shows a possible embodiment of a diaphragm-sealed valve 10. The valve 10 includes a bonnet 100, a valve body 200 engageable with the bonnet 100, a diaphragm 300 positioned between the bonnet 100 and the valve body 200, a plunger assembly 400 disposed within the valve body 200, an actuating assembly 500 adapted to effect movement of the plunger assembly 400, and a bottom cap 600 coupled to the valve body 200 opposite the bonnet 100. It should be appreciated that other components, such as various fixings and fasteners (e.g., screws, nails, bolts, nuts, washers, springs, etc.) and sealing elements (e.g., O-rings, etc.), may be provided in and / or with the valve 10. As will be described in conjunction with various embodiments, some of the components of the valve 10 are generally cylindrical in shape, such as the valve cover 100 , the valve body 200 , and the bottom cover 600 .

[0066] In the illustrated embodiment, the valve body 200 and the bottom cover 600 form an inner cavity 210 for receiving the actuating gas. As will be described below, the valve body 200 can be at least partially hollow, wherein the bottom cover 600 is configured to cooperate with the valve body 200 to close the hollow portion, thereby defining the inner cavity 210. It will therefore be understood that the valve 10 is pneumatically actuated and that the valve 10 includes a gas inlet 502 that communicates with the inner cavity 210 for providing actuating gas to the inner cavity 210 so as to shift the plunger assembly 400. In the illustrated embodiment, the valve is provided with a "normally closed" (or raised) plunger and a "normally open" (or lowered) plunger. The "normal" position of the plunger corresponds to when no actuating gas is injected. The position of the plunger in its "normal" or "default" state is determined by the Belleville assembly 540 and the wave spring 546. When actuating gas is injected into the inlet 502 of the valve, the pistons 420, 430 are spaced apart, thereby moving the normally closed plunger toward the open (or lowered) position and moving the normally open plunger toward the closed (or raised) position. However, it will be appreciated that other methods for actuating the plunger assembly 400 are also possible.

[0067] More specifically, refer to Figures 1 to 5 The valve bonnet 100 has a plurality of process conduits 102 extending through the thickness of the valve bonnet 100 and terminating in process ports 104. The valve bonnet 100 also includes a bonnet interface 106 adapted to face the valve body 200 (and the diaphragm 300), and the process ports 104 open to the bonnet interface 106. It should be appreciated that the valve bonnet 100 can be provided with any suitable number of process conduits 102 arranged in any suitable configuration, depending on the application of the valve 10. For example, in this embodiment, the valve bonnet 100 includes six process conduits 102 arranged in an annular shape, such that the process ports 104 are correspondingly arranged in an annular shape on the bonnet interface 106. In other embodiments, the valve bonnet 100 can be provided with four, eight, ten, twelve, or any other suitable number of process ports 102.

[0068] In this embodiment, the valve body 200 has a body engaging portion 202 that is adapted to face the valve cover 100 so that when the valve 10 is assembled, the diaphragm 300 can be positioned between the valve cover 100 and the valve body 200, such as between the cover engaging portion 106 and the body engaging portion 202. More specifically, the diaphragm 300 has a first surface, such as a top surface 302, and a second surface, such as a bottom surface 304. The first surface is adapted to contact the cover engaging portion 106 and the second surface is adapted to contact the body engaging portion 202 when the diaphragm 300 is installed between the valve cover 100 and the valve body 200.

[0069] like Figure 6and Figure 7 As seen in FIG, and with continued reference to the previous figures, the valve body 200 includes a recess 204 defined on a surface of the body-engaging portion 202 such that the recess 204 faces the bonnet-engaging portion 106. The recess 204 illustratively has an annular shape and is substantially concentric with respect to the body-engaging portion 202 (e.g., the center of the body-engaging portion 202 corresponds to the center point of the recess 204). When the valve 10 is assembled (i.e., when the bonnet 100 and the valve body 200 are connected together), the process port 104 of the bonnet 100 is preferably positioned to align with (i.e., open into) the recess 204. In some embodiments, the bonnet 100 and the valve body 200 can be connected to each other using a central fastener 207 and a pair of locating pins 205, but it will be appreciated that other configurations and / or connection means are possible and may be used. In some embodiments, the central fastener 207 may be provided with a sealing element, such as an O-ring near the head of the fastener, or a sealant provided along the threaded portion, to at least prevent air from infiltrating through the gap between the bonnet 100 and the central fastener 207 .

[0070] Still refer to Figure 6 and Figure 7 The valve body 200 further includes a plurality of plunger passages 206 extending at least partially through the valve body 200, the plunger passages 206 having first ends that open at respective locations along the recess 204 and second ends opposite the first ends that open at respective corresponding locations on the interior cavity 210. As will be further described below with respect to the plunger assembly 400, the plunger passages 206 are each shaped and sized to receive a plunger 402 and open to the recess 204 between two of the process ports 104.

[0071] In this embodiment, diaphragm 300 includes a process groove 306 shaped and sized to align with and engage recess 204 of valve body 200 . Thus, similar to recess 204 , process groove 306 is adapted to align with process port 104 of valve bonnet 100 and to align with plunger passage 206 of valve body 200 . It should be appreciated that process groove 306 is adapted to cooperate with bonnet engagement portion 106 to form a passage configured to allow fluid to circulate between at least two of process ports 104 . More specifically, diaphragm 300 engages bonnet engagement portion 106 such that a surface of bonnet engagement portion 106 overlies process groove 306 and forms a passage. In this embodiment, fluid can be injected into process groove 306 via one of process conduits 102 , and the fluid can then flow along the formed passage, for example, to process port 104 of a second of process conduits 102 .

[0072] like Figure 7, the plunger assembly 400 is illustratively adapted to be received within the valve body 200, and more specifically within the inner cavity 210. The plunger assembly 400 includes a plurality of plungers 402 that are slidably mounted within respective ones of the plunger passages 206, wherein the plungers 402 are movable between at least two positions. In this embodiment, each plunger 402 is movable between a closed position, in which the plunger 402 engages the process slot 306 of the diaphragm 300 to prevent fluid from flowing between at least two adjacent process ports 104, and an open position, in which the plunger 402 is spaced apart from the diaphragm 300, thereby allowing fluid to flow along the process slot 306. To reduce the risk of the plunger 402 becoming stuck within the respective plunger passages 206, the plunger passages 206 preferably have a diameter that is slightly larger than the diameter of the widest component of the plunger 402. The specific configuration and components of the plunger 402 will be further described below.

[0073] In some embodiments, as previously described, the plungers 402 can be of two types, commonly referred to as "normally closed" plungers and "normally open" plungers. As will be further described below, each plunger 402 of a given type is actuated together with the other plungers of the same type. In other words, the plungers 402 of a given type are either all in the closed position or all in the open position. In this embodiment, the normally closed plungers are biased toward the closed position, while the normally open plungers are biased toward the open position. It should be appreciated that the normally open plungers form a first group of plungers 402, while the normally closed plungers form a second group of plungers 402. In the illustrated embodiment, the plunger assembly 400 also includes a pair of pistons 420, 430 that operatively engage the plungers 402 for moving the plungers 402 up and down within their respective plunger channels 206. More specifically, plunger assembly 400 includes a first piston such as upper piston 420 operatively engaged with a first set of plungers (ie, normally open plungers) and a second piston such as lower piston 430 operatively engaged with a second set of plungers (ie, normally closed plungers).

[0074] Broadly describe and refer to Figures 7 to 10 , the pistons 420, 430 of the plunger assembly 400 are generally annular and parallel to the diaphragm 300. In the present embodiment, the upper piston 420 illustratively includes a central bore 424, and the lower piston 430 includes a piston head 434 that is shaped and sized to extend through the central bore 424 of the upper piston 420. It will be appreciated that the central bore 424 and the piston head 434 can be shaped in a complementary manner to allow movement of the pistons relative to each other while preventing the pistons from contacting each other and / or obstructing movement of the pistons. In such an embodiment, 3D printing technology can be used to manufacture the upper and lower pistons to allow assembly of the upper and lower pistons.

[0075] 11 . The lower push plate 432 may alternatively be formed integrally as part of the lower piston 430 and have a generally annular shape, such as, for example, Figure 9 and Figure 13 As shown in .

[0076] In some embodiments, the pistons (i.e., upper piston 420 and lower piston 430) and / or their corresponding push plates 422, 432 are preferably shaped and sized to engage only their corresponding set of plungers 402 (i.e., not contact or obstruct movement of the other set of plungers). Furthermore, the pistons 420, 430 can be configured such that the plungers 402 either fully seat on the corresponding pistons or partially seat on the corresponding pistons. In other words, the pistons can be adapted to push against the entire cross-section of the plunger 402 (e.g., Figure 7 、 Figure 8 and Figure 12 ) or the portion where the piston pushing the piston contacts about half of the lower end of the plunger 402 (as seen in FIG. Figure 14 and Figure 25 ). It will be appreciated that depressing the entire lower end of the plunger 402 may keep the plunger 402 relatively straight within the plunger passage 206, thereby providing a substantially uniform sealing force on the diaphragm 300 when the plunger is in the closed position, whereas depressing only a portion of the lower end may cause the plunger 402 to tilt slightly within the plunger passage 206, thereby providing an uneven sealing force on the diaphragm 300.

[0077] Various exemplary embodiments of the plunger assembly 400 are illustrated in the accompanying drawings and will now be described. Figures 8 to 10, the upper piston 420 has a plurality of upper recesses 426 and upper protrusions 428 arranged around a central aperture 424, and the lower piston 430 has a plurality of lower recesses 436 and lower protrusions 438 arranged around a piston head 434. The recesses and protrusions of each piston preferably have complementary shapes such that when the pistons are assembled, the upper protrusions 428 seat within the lower recesses 436 and the lower protrusions 438 seat within the upper recesses 426. In the illustrated embodiment, the plunger 402 is adapted to be engaged by the protrusions of the piston, whereby in this embodiment, the protrusions 428, 438 are shaped and configured to engage the entire diameter of the plunger 402. More specifically, the upper protrusions 428 are adapted to engage the entire diameter of a first set of plungers, and the lower protrusions 438 are adapted to engage the second set of plungers.

[0078] Refer to Figure 11 and Figure 12 , the piston head 434 illustratively has an annular shape, but it should be appreciated that the piston head 434 can have any suitable shape. In the illustrated embodiment, the lower piston 430 includes a lower push plate 432 that is removably connected to the piston head 434 and is shaped in a complementary manner relative to the central hole 424 of the upper piston 420. In this embodiment, the lower push plate 432 has a generally triangular shape, whereby each corner of the lower push plate 432 engages a plunger in the second set of plungers 402 (e.g., Figure 12 In this case, the upper push plate 422 is the top surface of the upper piston 420 and is adapted to directly engage the plunger 402 in the first set of plungers. Figure 12 As seen in FIG, the shape and size of the lower push plates 432 allow each set of plungers 402 to be fully seated on the corresponding push plates 422, 432.

[0079] Now refer to Figure 13 and Figure 14 , shows yet another embodiment of the plunger assembly 400. In this embodiment, the upper push plate 422 and the lower push plate 432 are provided with an upper recess 426 and a lower recess 436, respectively. The number of recesses of each push plate can correspond to the number of plungers 402 in each set of plungers. For example, in this embodiment, each set of plungers 402 includes three plungers, so that each push plate includes three recesses. The recesses are shaped and sized to allow the piston to be actuated (i.e., moved up and down) without causing the push plate to contact a plunger 402 engaged by another of the push plates. As Figure 14 As seen in FIG, each push plate 422, 432 is configured to contact approximately half of the lower end portion of the corresponding set of plungers 402, while the other half of the lower end portion of the plunger engages with one of the recesses 426, 436, thereby avoiding contact between the piston and its components.

[0080] Although the push plates 422, 432 and the corresponding plungers 402 are formed as separate / individual components in the illustrated embodiment, it should be appreciated that in other embodiments, the plungers and push plates may have other configurations and may be formed as, for example, a single component. Alternatively, the plungers may be fixedly connected to the push plates, for example, using screws or other fasteners.

[0081] Now refer to Figures 15 to 20 ,Apart from Figure 7 In addition, in some embodiments, the plunger 402 includes a plunger base 406 at its lower end that is engageable with one of the pistons. The plunger 402 also includes a plunger head 408 adapted to engage the diaphragm 300 (i.e., the process tank) from below when the plunger 402 is in the closed position, and a plunger body 410 extending between the plunger base 406 and the plunger head 408. The components of the plunger 402 can be made of a substantially rigid material, but other materials are possible, as will be further described below.

[0082] like Figure 20 As seen in FIG. 4 , the components of the plunger 402 can be independent of each other (ie, separate components) and stacked within the plunger channel 206, but a similar arrangement can also be used. Figure 15 4. In some embodiments, the plunger base 406 and the plunger head 408 have substantially the same shape, size, and / or configuration. More specifically, the plunger base 406 and the plunger head 408 are generally cylindrical and have a diameter slightly smaller than the diameter of the plunger passage 206 to avoid interference / contact between the valve body 200 and the plunger 402.

[0083] It is known that manufacturing defects may occur in various components of the plunger assembly 400, such as the piston, push plate, plunger, etc., which may cause one or more plungers 402 to have different lengths or misalignment within their respective plunger channels 206, thereby resulting in uneven sealing forces applied to the diaphragm 300. As such, adjustments may be required to avoid damage to the plungers 402, the valve body 200, the diaphragm 300, and / or to ensure proper operation of the valve 10.

[0084] In some embodiments, the shape and configuration of the plunger body 410 can be designed to adjust the plunger head 408 relative to the diaphragm 300. More specifically, the plunger body 410 can be configured to position the plunger head 408 substantially transverse to the diaphragm 300 (i.e., axially aligned within the plunger channel of the plunger head 408) so that the plunger head 408 exerts a substantially uniform sealing force on the diaphragm 300. For example, the plunger body 410 can include a stack of Belleville washers, or a compressible and / or resilient material (such as a spring or cushion) having a compressibility suitable for adjusting the alignment of the plunger head 408 when the plunger head 408 is engaged with the diaphragm 300. More specifically, if the plunger head 408 were to exert a higher than desired pressure on the diaphragm (due to the plunger being manufactured with an uneven length), the additional compressive force would be absorbed by the resilient material. Thus, the compressible plunger body element can compensate for imperfections in the geometry of the plunger or other valve components (flatness, parallelism, etc.), local thickness variations of the diaphragm, etc. This configuration of the plunger allows the application of force across the entire cross-sectional area of ​​the plunger base. Here, the compressible middle portion 410 is cylindrical, but can be any shape: hollow, conical, hourglass-shaped, etc.

[0085] like Figure 16 As seen in FIG, the plunger body 410 may also have a generally cylindrical shape and a similar diameter to the plunger base 406 and the plunger head 408. Figure 18 In some embodiments, the plunger body 410 includes at least two compressible body portions 412 extending between the plunger base 406 and the plunger head 408, whereby each body portion 412 has a corresponding compressibility. The compressible body portion 412 can be used to balance uneven forces applied by one of the pistons on the plunger base 406, such as when the piston engages only a portion (e.g., half) of the diameter of the plunger base 406. In some embodiments, the piston pushes against half of the plunger base 406, such that the sealing force applied to the diaphragm may be uneven across the cross-section of the plunger head 408. Thus, a plunger body 410 having two or more compressible body portions 412 can be adapted to correct or compensate for uneven sealing forces.

[0086] In other embodiments, such as Figure 15 and Figure 17 In embodiments of the present invention, the plunger body 410 can have a smaller diameter than the plunger base 406 and / or the plunger head 408 and can additionally be offset relative to the central longitudinal axis of the plunger 402 ( Figure 17) to adjust the plunger head 408 (e.g., if an uneven force is applied to the plunger base 406). It should be understood that in order for the offset plunger body 410 to adjust the plunger head 408 in a substantially consistent manner, the radial position of the plunger 402 must remain substantially the same. In other words, the rotation of the plunger 402 within the plunger channel 206 must be prevented to maintain the plunger body 410 in the appropriate radial position to adjust the force applied by the plunger head 408 to the diaphragm 300. For example, the shape of the plunger channel 206 and the plunger component can be non-annular so that the rotation of the plunger 402 is prevented without hindering the vertical movement of the plunger 402. It should be appreciated that other suitable methods for preventing the rotational movement of the plungers 402 within their respective plunger channels 206 are also possible and can be used.

[0087] In yet another embodiment of the plunger body 410, as Figure 19 and Figure 20 As shown, the plunger body 410 can have a spherical shape so that any uneven forces applied by the piston and / or plunger base 406 can be accommodated by the spherical design of the plunger body 410. It should be understood that the features of each embodiment of the plunger 402 described herein can be modified, simplified, changed, omitted, and / or interchanged depending on the specific application and / or desired end result for which the plunger is used, as briefly illustrated herein and apparent to those skilled in the art. In some embodiments, the spherical plunger body 410 can have a diameter that substantially matches the diameter of the plunger base 406 and / or plunger head 408. Thus, when the plunger 402 is in the closed position, compressive forces applied to the plunger 402 can cause the plunger body 410 to expand outward (due to the compressible material) and contact the walls of the plunger channel. As a result, deformation of the plunger body 410 is reduced / limited due to its larger diameter, thereby increasing its compressibility. The life of the plunger body 410 can also be increased due to the reduced deformation and resulting stress on the components of the plunger 402.

[0088] Return to reference Figures 2 to 4, the actuation assembly 500 can include an actuation system 538 configured to enable operation of the valve 10. More specifically, the actuation system 538 can be operated between an engaged configuration, in which actuation gas can be injected to actuate the plunger assembly 400, and a disengaged configuration, in which the injected actuation gas does not actuate the plunger assembly 400. In this embodiment, the actuation system 538 includes a Belleville assembly 540, which includes a stack of Belleville washers 542 that cooperate with the lower piston 430. Additionally, the actuation system 538 can include a compression screw 544 that is configured to apply a load / force on the stack of Belleville washers 542, thereby applying a load on the lower piston 430. In this way, the normally closed plunger 402 is biased toward the closed position because the lower piston 430 is biased upward via the activation system 538 (e.g., when the compression screw 544 is tightened). It should be appreciated that the activation system 538 may include any other biasing means for enabling the valve 10 to operate, such as by biasing the lower piston 430 upward, such as a standard spring or a polymer bushing. In this embodiment, the upper piston 420 is biased downward (e.g., toward the lower piston 430) by appropriate means. In the illustrated embodiment, a wave spring 546 is disposed within the valve body 200 and above the upper piston 420, and the wave spring 546 is adapted to exert a downward force on the upper piston 420. In this way, the normally open plunger 402 is effectively biased toward the open position.

[0089] When stored for extended periods, the normally closed plunger of known valves continuously pushes against the diaphragm. Over time, creep can cause the shape of the diaphragm process groove to change, thereby reducing the groove height and increasing flow restriction. By reducing or removing this pushing force, this phenomenon and its negative effects can be reduced / prevented. In other words, by moving the activation system 538 into the disengaged configuration, the compression screw 544 is loosened, and the lower piston (and corresponding plunger) is allowed to move away from the diaphragm.

[0090] Now refer to Figure 21 and Figure 22, the valve 10 can be provided with a storage mechanism 610 that operatively engages the compression screw 544 and is configured to indicate the position of the compression screw 544. Thus, the configuration of the storage mechanism 610 can facilitate determining the state of the valve 10 (e.g., in operation, in standby, in storage, etc.) based on the position of the compression screw 544. In this embodiment, the storage mechanism 610 includes a set screw 612 that extends through the bottom cover 600 to engage the compression screw 544. Furthermore, the compression screw 544 can be provided with a notch or recess 545 into which the set screw 612 can extend when the compression screw is in a predetermined position. The set screw 612 can assist in positioning the compression screw 544 in a desired position and can facilitate determining the state of the valve 10.

[0091] It should be appreciated that the described embodiments are exemplary and that other mechanisms, devices, components and / or methods may be used to determine the state of the valve and may be employed. For example, guide recesses, grooves or markings may be used instead to allow a user to use a set screw 612 or other similar guide to determine whether the valve is in a "storage" configuration or an "in use" configuration based on the rotational / angular position of the compression screw 544 relative to the bottom cover 600. Figure 21 In the example shown, a spring plunger 610 is positioned on the bottom cap, pushing against the preload screw. A recess 545 is formed in the preload screw 544 to provide a feel as the spring plunger ball moves across the recess. The recess 545 is positioned to allow sufficient preload pressure relief (typically between 1 / 4 and 1 / 2 turns). When the valve is ready for use / installation, the end user simply fully tightens the preload screw to restore the valve's operating preload.

[0092] In the illustrated embodiment, the actuation assembly 500 is operable to actuate the two sets of plungers 402 between an open position of the two sets of plungers 402 and a closed position of the two sets of plungers 402. As described above, the valve 10 is pneumatically actuated, whereby actuating gas is injected into the valve body 200 to control the distance between the upper piston 420 and the lower piston 430. When not actuated, as shown in FIG. Figure 2As shown, the two pistons are in contact because they are urged toward each other by the Belleville assembly 540 and the wave spring 546. The actuating mechanism 500 preferably includes a pneumatic actuator for supplying actuating gas between the upper piston 420 and the lower piston 430 via the gas inlet 502. When the valve is actuated, the gas will balance the bias of the two pistons by pushing the upper piston 420 upward, thereby sliding the normally open plunger toward the closed position, and then pushing the lower piston 430 downward, thereby allowing the lower push plate and / or the normally closed plunger 402 to move downward and toward the open position. It should be understood that when the actuating gas is no longer injected, the biasing action of the Belleville assembly 540 and the wave spring 546 will return the pistons 420, 430 to their initial positions (i.e., pre-actuation) of the pistons 420, 430.

[0093] like Figure 2 and Figure 7 As seen in FIG, the upper piston 420 and the lower piston 430 are located within the inner cavity 210 formed by the valve body 200 and the bottom cover 600. In this embodiment, the inner cavity 210 includes a top region 212, a bottom region 214, and a middle region 216. The top region 212 is generally located between the upper piston 420 and the plunger passage 206, the bottom region 214 is located between the lower piston 430 and the bottom cover 600, and the middle region 216 is located between the upper piston 420 and the lower piston 430. As described above, actuating gas is injected between the upper piston 420 and the lower piston 430 (i.e., in the middle region 216) for actuating the pistons. The gas inlet 502 is illustratively in fluid communication with the middle region 216 to allow actuating gas to be injected into the middle region 216. In the illustrated embodiment, the gas inlet 502 is positioned generally aligned with the intermediate region 216 to facilitate the injection of actuating gas, but it should be appreciated that other configurations are possible, and the gas inlet 502 can be positioned at any other suitable location. Furthermore, the inner cavity 210 can be provided with a sealing element 211 configured to prevent the actuating gas from escaping from a desired area. In this embodiment, a pair of O-rings are positioned between the pistons 420, 430 and the walls of the inner cavity 210, such that actuating gas injected into the inner cavity 210 is forced between the pistons.

[0094] Now refer to Figure 6 、 Figure 7 and Figure 10 , the actuator assembly 500 further includes a purge system 510 configured to effectively purge an area 512 located between the bottom surface of the diaphragm 304 and the body engagement portion 202, the area 512 being hereinafter referred to as the "purge area" 512. In some embodiments, and as Figure 6As seen in FIG. 5 , purge area 512 includes an inner purge area 512a corresponding to an area along recess 204 of valve body 200 below diaphragm 300 (i.e., below process slot 302 of diaphragm 300) and an outer purge area 512b corresponding to an area between recess 204 and the inner wall of valve body 200. In this embodiment, purge system 510 includes an inner purge circuit 514 comprising one or more channels integrally formed within a component of valve 10 and adapted to direct gas / fluid to purge area 512. As will be further described below, in the illustrated embodiment, the purge circuit allows actuating gas injected via gas inlet 502 to flow along the channels to reach purge area 512 and then exit the interior of valve 10, thereby effectively purging purge area 512. In other words, purge system 510 allows at least a portion of the injected actuating gas to serve as purge gas to effectively purge the area below diaphragm 300 (i.e., purge area 512).

[0095] In some embodiments, the passages of the purge circuit 514 may define one or more paths for directing and / or forcing the actuating gas to the inner purge region 512a and / or the outer purge region 512b. Figure 7 In the embodiment of the present invention, the purge circuit 514 includes a first controlled flow channel 516 that is configured to establish fluid communication between the middle region 216 (i.e., where the actuating gas is initially injected) and the top region 212. The controlled flow channel 516 illustratively extends through the upper piston 420 to effectively connect the middle region 216 and the top region 212, but it should be appreciated that other configurations are possible, such as providing one or more external conduits for directing gas from one region to another.

[0096] When the actuating gas is located in the top region 212, the gas can be directed to the internal purge region 512a before exiting the valve 10, thereby effectively purging the region 512a. Figure 7A As seen in FIG. 1 , the purge circuit 514 includes a first path along which actuating gas can flow to purge the internal purge region. In this embodiment, the first path includes: A) injection of actuating gas into the middle region 216; B) actuating gas flowing through the controlled flow channel 516; C) actuating gas flowing into the top region 212; D) actuating gas flowing into the internal purge region 512a; and D) actuating gas exiting the valve 10.

[0097] In this embodiment, the top region 212 is in fluid communication with the purge region 512 via the plunger channel 206 extending through the valve body 200. The plunger channel 206 can be slightly larger than the plunger 402 inserted into the plunger channel 206, thereby forming a gap through which fluid (e.g., actuating gas) can flow to reach the purge region 512. It should be appreciated that gas flowing through the plunger channel 206 is generally restricted to flow into the interior purge region 512a because the plunger channel 206 is always open to the recess 204. In some embodiments, and as Figures 15 to 18 As seen in FIG, the plunger 402 can be provided with a groove 404 extending along the outer surface of the plunger 402 to facilitate fluid communication between the top region 212 and the clearance region 512. The groove 404 can be spiral and / or vertically oriented, but it should be appreciated that other configurations are possible. For example, the plunger 402 can be provided with a structure extending through the plunger 402 (rather than around the outer surface) to allow fluid to reach the clearance region 512 (not shown).

[0098] Return to reference Figure 7 , the controlled flow passage 516 can be provided with a first flow restrictor 518 adapted to at least partially prevent fluid flow through the controlled flow passage 516 to allow actuating gas to accumulate in the intermediate region 216 for actuating the pistons 420, 430 as described above. In an exemplary embodiment, the first flow restrictor 518 includes a first check valve 519 configured to prevent fluid flow therethrough until a predetermined pressure in the intermediate region 216 is reached. The first check valve 519 has a first cracking pressure corresponding to a pressure at which the first check valve 519 opens to allow fluid flow through the controlled flow passage 516 and into the top region 212. The cracking pressure generally corresponds to a minimum upstream pressure at which the check valve will operate and can be provided in psi, psig, kPa, MPa, etc.

[0099] In the illustrated embodiment, the valve 10 includes a gas outlet 504 for allowing actuating gas to exit the valve 10. In some embodiments, the gas outlet 504 is positioned so as to establish fluid communication between the inner cavity 210 and the surrounding environment. Thus, the pressure within the valve 10 can be controlled and / or regulated by allowing some of the gas to exit the valve via the gas outlet 504. In this embodiment, the gas outlet 504 specifically establishes fluid communication between the top region 212 of the inner cavity 210 and the surrounding environment. In this way, actuating gas located in the top region 212 can flow to the purge region 512 (via the plunger passage 206) and / or to the outlet 504.

[0100] In this embodiment, the purge system 510 includes an outlet flow restrictor 520 that is adapted to at least partially prevent gas from flowing through the outlet 504, thereby forcing the gas upward into the plunger passage 206 and into the purge area 512. The outlet flow restrictor 520 can be a check valve 521 having an outlet opening pressure set to allow fluid to flow therethrough when the pressure within the top region 212 is at or above the outlet opening pressure. It should be understood that the pressure in the top region 212 is substantially the same as the pressure in the internal purge area 512a, such that the pressure within the internal purge area 512a is required to reach the outlet opening pressure before the check valve 521 can open. It should also be appreciated that the outlet opening pressure is preferably higher than the first opening pressure so that fluid (e.g., actuating gas) can be directed to the purge area 512 before being discharged through the outlet 504. In some embodiments, the outlet cracking pressure is set above the ambient atmospheric pressure to maintain the top region 212 and the internal purge region 512a above the atmospheric pressure during normal use of the valve 10 .

[0101] In some embodiments, the flow of gas between the middle region 216 and the top region 212 can be controlled. Figure 7 and Figure 10 As seen in FIG. 5 , the controlled flow passage 516 may include a flow restrictor 522 shaped and configured to restrict the flow rate of gas flowing therethrough. The flow restrictor 522 may simply comprise a passage 524 having a reduced diameter and communicating with the outlet of the first flow restrictor 518 (e.g., the first check valve 519) to restrict the flow rate of gas flowing into the top region 212 to a predetermined flow rate. The flow restrictor 522 advantageously allows the valve 10 to be actuated while reducing the amount of actuating gas injected through the inlet 502 to purge the purge region 512. The passage 524 of the flow restrictor 522 may have any suitable shape and size, such as a straight passage, a spiral passage, a tortuous passage, etc.

[0102] In other embodiments, such as Figure 10In the illustrated embodiment, the flow restrictor 522 can include a removable insert 525 that is engageable in an insert slot 526 provided in the upper piston 420 proximate the outlet of the first check valve 519. In an embodiment, a passage 524 is defined through the removable insert 525, whereby positioning the insert 525 in the insert slot 526 connects the passage 524 with the outlet of the first check valve 519 to restrict the flow rate of the fluid. A plurality of removable inserts 525 can be provided with passages 524 of different sizes and / or shapes, thereby allowing the flow rate to be selectively adjusted based on the selection of the insert 525. In some embodiments, the flow rate of the fluid passing through the flow restrictor 522 can be reduced to about 0.5 cm / s. 3 / min and about 2cm 3 Alternatively or additionally, a single removable insert 525 may be provided with multiple passages 524 having different diameters, whereby changing the orientation (i.e., radial position) of the insert 525 engaged in the insert slot 526 effectively changes the passage 524 connecting the check valve 519 with the top region 212.

[0103] like Figures 23A to 23C As shown, and refer to Figure 2 and Figure 7 , the first check valve 519 and / or the outlet check valve 521 also have respective closing pressures (i.e., a first closing pressure and an outlet closing pressure) that cause the check valves to close. More specifically, once the pressure within the top region 212 and the internal purge area 512a reaches the outlet opening pressure, the outlet check valve 521 opens to allow gas to exit the valve via the outlet 504, effectively dragging debris and other impurities from the internal purge area 512a along with the internal purge area 512a. As the gas exits the valve, the internal purge area 512a is purged and the pressure decreases. Once the outlet closing pressure is reached, the outlet check valve 521 closes accordingly and allows gas to be redirected to the internal purge area 512a. Pressure builds within the top region 212 and the internal purge area 512a until the outlet opening pressure is reached, and the cycle repeats.

[0104] Existing purge gas chromatography (GC) diaphragm valves typically require a continuous purge flow supplied via a flow orifice connected to a carrier gas supply. This consumes additional carrier gas, and when using a capillary column, the purge flow is the same as the carrier gas flow. Therefore, this type of configuration is inconvenient and expensive in terms of carrier gas when primarily using helium.

[0105] The purpose of the purge system described above is to provide an inert area below the diaphragm to avoid atmospheric air from penetrating through the diaphragm. This is a real problem for diaphragm valves that are not purged. Allowing atmospheric air to penetrate through the diaphragm can result in carrier gas contamination, which will interfere with the analytical results. Purging can also reduce and possibly eliminate the accumulation of harmful impurities below the diaphragm. With the proposed valve and method, instead of relying on dynamic purging, i.e. continuous flow, a "static" purging process is used. The proposed method relies on using a carrier gas to generate pressure in the target volume (i.e. the purge area) and reducing the pressure to a value just above atmospheric pressure, thereby diluting the air that enters the target volume, i.e. the space below the diaphragm. After a few cycles, there is no more air below the diaphragm, as shown in FIG. Figure 23D This can be seen in the exemplary embodiment of FIG.

[0106] In addition to reference Figures 7 to 10 In addition, we still refer to Figures 23A to 23C When the valve (typically a three-way solenoid valve) controlling the entry of the carrier / actuating gas supply is actuated, the carrier gas will first flow through the check valve 519 (CV1) and through the flow orifice 524 (R1), thereby limiting the actual flow rate entering the volume and slowly pressurizing the carrier gas. When the pressure in this area reaches the opening pressure of the second check valve 533 (CV2), for example, approximately 1 PSIG, the check valve 533 (CV2) will open. Once opened, the flow rate through the second check valve will be higher than the flow rate through the orifice 524. This is achieved by selecting an orifice size that is much smaller than the cross-section of the second check valve (for example, in the range of 0.0005 inches). As a result, the pressure entering the purge area will decrease and the second check valve will close. In some embodiments, it may be useful to provide a filter or filtration system (not shown) connected to the first check valve (CV1) to effectively filter the gas before it reaches the orifice (R1) to prevent clogging / blocking of the orifice. It will be appreciated that any other restriction, such as, for example, a restrictive filter, may be used in place of orifice (R1).

[0107] like Figure 23BAs shown, there is a difference between the opening pressure and the closing pressure of the first check valve and the second check valve, thereby producing a hysteresis of the valve. The pressure cycle will continue until the actuating gas / carrier gas supply valve is shut off. At this stage, the flow stops in the volume portion / purge region, but the volume portion will still be pressurized to a value between the closing pressure and the opening pressure because the second check valve is closed, thereby isolating the volume portion from the atmosphere. After several pressure cycles, all air is almost completely eliminated from the purge volume portion through dilution. Therefore, actuating gas consumption will only occur when the actuating gas inlet / solenoid valve is opened. Typically, a flow target of approximately 1 SCCM (standard cubic centimeter per minute) driven by the actuating pressure and the size of the orifice 524 are sufficient to ensure appropriate purging while effectively limiting excessive gas use.

[0108] Reference Figure 23C as well as Figure 2 、 Figure 7 and Figure 10 , valve SV1 is used to actuate the valve. When SV1 is actuated, the carrier gas / actuating gas pressurizes the volume between the pistons, causing the pistons to separate. In the upper piston plate, there is a built-in first check valve 519 and flow orifice 524, which are located in the Figure 23C The second check valve 533, CV2, is fitted into the side wall of the valve, as shown in FIG. Figure 7 Alternatively, the second check valve 533 (CV2) may be installed at the end of a tube connected to the discharge port of the volume defined by the upper piston of the valve.

[0109] Still refer to Figure 23A and Figure 23B , the graph shows that the pressure in the internal purge region 512a oscillates between the outlet opening pressure and the outlet closing pressure ( Figure 23B ), thereby generating a pulsed purge cycle during which the purge zone is effectively purged. In some embodiments, the outlet opening pressure can be between about 0.5 psig and about 1.5 psig, causing the pressure within the purge zone 512 to rise to or above the pressure of the surrounding environment, but it should be appreciated that other pressures are possible. It should be understood that the unit "psig" refers to pounds per square inch gauge, which generally represents the pressure difference between the supply tank or chamber and the outside air. Additionally, the outlet closing pressure can be any suitable pressure that allows for a pulsed purge cycle as described herein.

[0110] The pulse purge cycle is performed during normal use of the valve because the purge system uses actuating gas injected via the gas inlet to perform the purge. The pressure of the injected actuating gas can depend on the load applied to the lower piston via the compression screw. For example, the actuating gas can be injected at a pressure between about 50 psig and about 70 psig, but it should be appreciated that any other pressure can be used depending on the specific application and / or desired end result for which the valve is used. For example, Figure 23A As shown, actuating gas is injected through inlet 502 to provide sufficient pressure to effectively actuate valve 10. In this embodiment, the pressure near the inlet remains substantially constant when valve 10 is actuated (i.e., opened) and drops back to approximately zero when the valve is closed. It should be noted that once the valve is closed, the pressure in the purge region is no longer as high as Figure 23B As shown, the pulse purge cycle fluctuates between the outlet opening pressure and the outlet closing pressure, thereby isolating the volume portion to a pressure between the outlet opening pressure and the outlet closing pressure. Since the need for a continuous purge flow through the valve 10 is eliminated, the pulse purge cycle can also reduce the amount of gas used during normal use of the valve.

[0111] In short, each time the valve is actuated, the volume defined between the diaphragm and the upper piston cycles between the opening and closing pressures of CV2. This cycle repeats until SV1 closes. At this point, the valve is not actuated and no further flow occurs through it until the next actuation. By flowing around the plunger, purge gas is allowed to reach the space below the diaphragm.

[0112] As previously mentioned, the static purge cycle occurs only when the valve is actuated, and therefore the carrier / actuating gas serves as the purge gas supply only during valve actuation. Because the system uses the actuating gas as the purge gas, no additional inlet purge port is required. Another benefit of this approach is that the volume / region below the diaphragm is always above atmospheric pressure, which helps reduce atmospheric air diffusion back into the valve and significantly reduces the penetration of impurities from the sample into the purge region.

[0113] It should be noted that both check valves can be installed on the outside of the valve. However, additional pipes and fittings will be required, and the compact advantage of the fully integrated design will be greatly reduced. Sometimes this trade-off may be needed, for example, when it is necessary to recycle the purge gas for recycling purposes or appropriate waste disposal. Thus, in some embodiments, the outlet 504 can be adapted to have a pipe connected to the outlet 504 for guiding the gas leaving the valve to another component / equipment (e.g., for gas recycling or processing). In other embodiments, when using unfiltered and / or dirty actuating gas, it may be useful to position the check valve on the outside of the valve 10, and the valve 10 can be connected to a filtration system (not shown) via an additional pipe (or other device) for connecting the check valve to the valve. It should also be noted that the valve 10 can be provided with any suitable number of check valves (or other similar and / or restrictive devices) within its structure (i.e., fully integrated), outside its structure (i.e., connected with additional pipes and fittings), or in a combination thereof.

[0114] Still refer to Figure 23A 、 Figure 23B 、 Figure 23C 、 Figure 2 、 Figure 7 and Figure 10 , but also refer to Figure 8 and Figure 15 , because the spacing / clearance between the plunger and its corresponding plunger channel may be very small, this may restrict the flow or air exchange between the actuation line and the purge area located below the diaphragm. This restriction slows down the purge process, thereby limiting the effectiveness of the proposed purge system. In order to limit the impact of such close tolerances between the plunger and the channel sidewalls, spiral / helical grooves can be formed on the outer surface of the plunger, such as Figure 15 As best shown, the grooves 404 ensure that there is always fluid exchange between the base portion and the head portion of the plunger, thereby making the pulse purge method effective.

[0115] Now, in addition to the reference Figure 2 、 Figure 7 、 Figure 10 as well as Figures 23A to 23C In addition, refer to Figure 23D The pulse purge method may be useful to eliminate or at least reduce the amount of impurities (e.g., debris from the environment, residual gas from previous measurements, etc.) present in certain areas or compartments of the valve 10. Figure 23DAs can be seen in FIG. 5 , the impurity concentration decreases exponentially with each subsequent pulse of the pulse purge cycle. In an exemplary embodiment, the purge volume is substantially equal to 0.5 mL, and the gas flow rate through the outlet 504 is maintained at approximately 1 mL / min. Thus, the purge volume is completely renewed / purged once every 30 seconds. Assuming a dilution of approximately 50% of the fluid every 30 seconds (i.e., the amount of air is substantially halved after every 30 seconds), actuating the valve 10 for approximately 5 minutes will result in the purge volume being renewed approximately 10 times and the amount of air being reduced, and thus the impurity concentration being below approximately 0.1% (e.g., Figure 23D ). It will be appreciated that continuing to actuate the valve for an additional 5 minutes can reduce the amount of air in the purge volume to less than about 1 PPM, such that it can be estimated that there is no air in the purge volume. However, it will be appreciated that other configurations are possible depending on the desired results and settings of the various components of the valve 10 (e.g., fluid flow through the outlet 504, the volume of the purge area, etc.).

[0116] Now refer to Figures 24 to 26 Alternatively or additionally, the purge circuit 514 may include a passageway defining a second path to allow actuating gas injected via the inlet 502 to reach the purge region 512. For example, the second path may be configured to direct actuating gas from the inlet 502 to the outer purge region 512b, while the first path is configured to direct actuating gas to the inner purge region 512a, as described above. Thus, the purge circuit 514 may allow actuating gas to reach both the inner purge region 512a (via the first path) and the outer purge region 512b (via the second path), such that a majority of the area beneath the diaphragm 300 is purged during use of the valve 10 (e.g., on both sides of the recess 204).

[0117] like Figure 24 As seen in FIG, the purge circuit 514 can include one or more external passages 528 extending through a portion of the valve body 200 to establish fluid communication between the top region 212 of the interior chamber 210 and the external purge region 512b. In this embodiment, the external passages 528 are substantially straight (e.g., vertical) and free of obstructions, but it will be appreciated that other configurations are possible. For example, the external passages 528 can have a tortuous configuration to reduce the flow rate of gas entering the external purge region 512b. Furthermore, in the illustrated embodiment, the purge circuit 514 includes two external passages 528 disposed substantially opposite each other within the valve body 200. However, it will be appreciated that the purge circuit 514 can include any other suitable number of external passages 528, such as, for example, a single external passage or more than two external passages.

[0118] Thus, it should be understood that the outer purge region 512b can be subjected to substantially the same pulse purge cycle as previously described. In fact, both the inner purge region 512a and the outer purge region 512b are in fluid communication with the top region 212 connected to the outlet 504. Thus, in this embodiment, the pressure within the inner purge region 512a varies in substantially the same manner as the pressure within the outer purge region 512b, although other configurations are possible.

[0119] In other embodiments, and as Figure 25 As shown, the external channel 528 can be in direct fluid communication with the gas inlet 502 without being connected to the inner cavity 210. In this embodiment, the purge circuit 514 includes a first channel 515a and a second channel 515b. The first channel 515a extends between the gas inlet 502 and the inner cavity 210, and the second channel 515b extends from the first channel 515a at a first end of the second channel 515b and opens to the outer purge region 512b at an opposite end. Thus, the actuating gas injected through the gas inlet 502 can flow into the inner cavity 210 via the first channel 515a and flow to the purge region 512 via the second channel 515b. It should be understood that in this case, the second channel 515b is one of the external channels 528, and the purge circuit 514 illustratively includes a single external channel 528. However, it should be appreciated that other configurations are possible.

[0120] In the illustrated embodiment, the outer passage 528 can include a second flow restrictor 532 adapted to at least partially prevent fluid from flowing through the outer passage 528, thereby defining a second controlled flow passage 530. More specifically, the second controlled flow passage 530 can be configured to establish fluid communication between the gas inlet 502 and the outer purge region 512b. The second flow restrictor 532 can prevent fluid from flowing through the second controlled flow passage 530, thereby forcing the actuating gas along the first passage 515a into the inner cavity 210 to actuate the piston.

[0121] In an exemplary embodiment, the second flow restrictor 532 includes a second check valve 533 configured to prevent fluid flow therethrough until a predetermined pressure upstream of the second check valve 533 is reached. The second check valve 533 has a second cracking pressure corresponding to the pressure at which the second check valve 533 opens to allow fluid to flow through the second controlled flow passage 530 and into the purge area 512 (i.e., the outer purge area 512b). It should be understood that the intermediate region 216, the first passage 515a, and the second passage 515b are in fluid communication with each other such that the pressure in each of these portions is substantially the same. Therefore, it should be understood that once the pressure in the intermediate region 216 reaches the second cracking pressure, the second check valve 533 effectively opens and allows fluid to flow to the outer purge area 512b.

[0122] Furthermore, the purge circuit 514 may additionally include internal passages shaped and configured to connect portions of the purge zones 512a, 512b to one another, thereby allowing for a more uniform distribution of gas within these zones and / or allowing for more efficient purge of the purge zones. Figure 25 , the purge circuit 514 may include a plunger purge passage 534 positioned to establish fluid communication between the outer purge region 512b and an area of ​​the purge region 512 proximate the central fastener 207 (e.g., between a recess of the valve body and the central fastener 207). It will be appreciated that alternative or additional channels / passageways may be provided within the structure of the valve 10 to allow actuating gas to flow into and out of various areas and / or portions, thereby achieving a more efficient purge cycle.

[0123] Reference Figure 25 and Figure 26 , the gas outlet 504 is in fluid communication with the external purge region 512b via an outlet opening 505 defined in the valve body 200 and defined within the external purge region 512b. As previously described, the gas outlet 504 can be provided with an outlet flow restrictor 520 to ensure that the pressure within the external purge region 512b reaches the outlet cracking pressure before exiting the valve 10. The gas outlet 504 can have an orifice shaped and sized to allow a predetermined purge flow (i.e., the actuating gas flow exiting the purge region) to exit the valve 10. For example, in some embodiments, the gas outlet 504 is shaped and sized to allow a gas purge flow of approximately 1 sccm to exit the valve, although other configurations are possible. Again, it should be appreciated that in this embodiment, the external purge region 512b is subjected to a pulsed purge cycle similar to the pulsed purge cycle previously described with respect to the internal purge region 512a.

[0124] As can now be appreciated, embodiments of the valves described herein allow the use of an actuating gas and purging the area between the diaphragm and the valve body via a pulse cycle. In other words, a scavenging system can be used to create a controlled atmosphere / environment in an area (i.e., a scavenging area) below the diaphragm that is typically filled with a carrier gas. Utilizing a scavenging area filled with a carrier gas, it will be understood that the osmotic exchange between the process stream along the diaphragm and the scavenging area will be composed of carrier gas molecules traveling from one side of the diaphragm to the other. Therefore, when the nature of the process changes (e.g., the fluid flowing along the process stream changes), new molecules will attempt to pass through the diaphragm (by osmosis). These molecules will be captured by the scavenging system and / or diluted in the volume portion of the scavenging area. Advantageously, if these molecules are inherently dangerous, they can be processed in a controlled and safe manner.

[0125] In some embodiments, each cycle (i.e., each pulse) of the purge system can be adapted to repeatedly and effectively purge the same area or to effectively purge various areas according to a predetermined sequence or as needed. Furthermore, the purge circuit of the described valve is advantageously completely defined within the valve, i.e., the purge circuit is an integral part of the valve and is completely contained within the valve, thereby eliminating the need for external piping and / or specific purge gas inlets / outlets other than the actuating gas inlet / outlet. It should be noted that the pulsed purge cycle described above can be applied to other applications and can use fluids other than the actuating gas of the valve 10.

[0126] A corresponding method for purging a purge region surrounding a diaphragm (e.g., below the diaphragm) using one of the described embodiments may include the following steps: a) injecting actuating gas into the valve via a gas inlet; b) directing the actuating gas along a purge circuit so that the actuating gas reaches the purge region; c) pressurizing the purge region; d) releasing the actuating gas from the valve via a gas outlet, thereby effectively purging the valve. It should also be noted that in addition to or instead of pressurizing the purge region, the method may include connecting the purge region to a vacuum.

[0127] Furthermore, while the embodiments of the valve and its counterparts are comprised of certain geometric configurations as described and illustrated herein, not all of these components and geometric structures are essential and, therefore, should not be considered in a limiting sense. It should be understood, and as will be apparent to one skilled in the art, that other suitable components and the fits therebetween, as well as other suitable geometric configurations, may be used for the valve, as briefly described herein and readily inferred by one skilled in the art. Furthermore, it should be appreciated that, unless otherwise indicated, positional descriptions such as "top," "bottom," "up," "down," "left," "right," etc., should be considered in the context of the accompanying drawings and should not be considered limiting.

[0128] Furthermore, in the context of this specification, it will be understood that all elongated objects will have an implicit "longitudinal axis" or "centerline," such as, for example, the longitudinal axis of a plunger, the centerline of a passageway of a purge circuit, and that expressions such as "connected" and "connectable" or "mounted" and "mountable" may be interchangeable as the invention includes various components for assembling the resulting fully assembled and fully operable valve, and / or associated plunger assembly and / or actuator assembly.

[0129] Furthermore, the components of the invention and / or steps of the methods described herein may be modified, simplified, changed, omitted and / or interchanged, as briefly illustrated herein and as will be apparent to those skilled in the art, depending on the particular application for which the invention is used and the desired end result, without departing from the scope of the invention.

[0130] A number of alternative embodiments and examples have been described and illustrated herein. The embodiments of the present invention described above are intended to be exemplary only. Those of ordinary skill in the art will appreciate the features of the various embodiments and the possible combinations and variations of components. Those of ordinary skill in the art will also appreciate that any of the embodiments may be provided in any combination with other embodiments disclosed herein. It should be understood that the present invention may be implemented in other specific applications or configurations. Therefore, the present examples and embodiments should be considered in all respects to be illustrative and not restrictive, and the invention is not limited to the details given herein. Therefore, although specific embodiments have been illustrated and described, many variations are conceivable without significantly departing from the present invention.

[0131] In this disclosure, an embodiment is an example or implementation of a diaphragm valve. Various appearances of "one embodiment," "an embodiment," or "some embodiments" do not necessarily refer to the same embodiment. Although various features may be described in the context of a single embodiment, these features may also be provided individually or in any suitable combination. Conversely, although a diaphragm valve may be described in the context of separate embodiments for clarity, a diaphragm valve may also be implemented in a single embodiment. References in the application documents to "some embodiments," "one embodiment," "one embodiment," or "other embodiments" mean that the particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least some embodiments, but not necessarily in all embodiments.

[0132] It should also be appreciated that like features of the drawings have been given like reference numerals. In order to maintain clarity of the drawings, some reference numerals have been omitted where they have been marked in previous drawings.

Claims

1. A diaphragm valve for gas analysis applications, comprising: a valve bonnet provided with a plurality of process conduits extending therethrough, the valve bonnet having a bonnet engagement portion, and each of the process conduits including a process port opening into the bonnet engagement portion; a valve body engageable with the valve cover and having a body engaging portion adapted to face the cover engaging portion and provided with a recess, the valve body including a plurality of plunger channels extending through the valve body whereby the plunger channels open to the recesses; a diaphragm positioned between the bonnet and the valve body and having a process groove for circulating a fluid therein, the process groove being shaped and sized to engage the recess of the valve body; a plunger assembly disposed within the valve body, the plunger assembly comprising a plurality of plungers slidably fitted within a corresponding one of the plunger passages, each plunger being movable between a closed position and an open position, wherein the plunger engages the diaphragm and blocks fluid from circulating along the process tank between the two process ports, and wherein the plunger is spaced apart from the diaphragm, thereby allowing fluid to circulate along the process tank; an actuating assembly comprising a gas inlet extending through the valve body to permit injection of actuating gas to move the plunger between the open and closed positions, the actuating assembly further comprising a purging system defining a purging circuit between the gas inlet and the plunger passage for purging a purging area between the diaphragm and the body joint, wherein the actuating gas injected to move the plunger is directed from the gas inlet to the purging circuit and is used to purge the purging area.

2. The diaphragm valve according to claim 1, comprising a bottom cover connected to the valve body and defining an inner cavity with the valve body, and wherein The plunger assembly includes an upper piston operatively engaged with a first set of plungers and a lower piston engaged with a second set of plungers, the upper and lower pistons being disposed within the interior cavity whereby the interior cavity is in fluid communication with the purge region via the plunger passage.

3. The diaphragm valve according to claim 2, wherein: The first group of plungers are normally open plungers, and the second group of plungers are normally closed plungers.

4. The diaphragm valve according to claim 2, wherein: The inner cavity includes a top area located between the upper piston and the plurality of plunger channels, a bottom area located between the lower piston and the bottom cover, and an intermediate area located between the upper piston and the lower piston, and wherein the gas inlet is positioned to allow actuating gas to be injected into the intermediate area for actuating at least one of the upper piston and the lower piston.

5. The diaphragm valve according to claim 4, wherein The scavenging system includes a controlled flow channel adapted to establish fluid communication between the middle region and the top region. The diaphragm valve according to claim 5 , wherein: The controlled flow passage includes a first flow restrictor configured to restrict fluid flow through the controlled flow passage to generate pressure in the intermediate region.

7. The diaphragm valve according to claim 6, wherein: The first flow restrictor is a first check valve having a first cracking pressure and configured to allow fluid flow therethrough when pressure within the intermediate region is above the first cracking pressure.

8. The diaphragm valve according to claim 7, wherein: The controlled flow passage also includes a flow restrictor having a passageway in fluid communication with an outlet of the first check valve, the passageway being shaped and sized to restrict a flow rate of actuating gas flowing from the middle region to the top region.

9. The diaphragm valve according to claim 8, wherein The upper piston includes a recess, and wherein the flow restrictor includes a removable insert adapted to engage the recess of the upper piston, the passage extending through the removable insert.

10. The diaphragm valve according to claim 8, wherein The passage is shaped and sized to limit the flow rate between the middle region and the top region to 0.5 cm 3 / min and 2cm 3 / min.

11. The diaphragm valve according to claim 8, wherein The actuation assembly also includes a gas outlet positioned to establish fluid communication between the interior cavity and the surrounding environment.

12. The diaphragm valve according to claim 11, wherein The gas outlet includes an outlet flow restrictor adapted to at least partially prevent gas from exiting the inner cavity, thereby directing the actuation gas to the purge region via the plunger passage.

13. The diaphragm valve according to claim 12, wherein: The gas outlet is in communication with the top region, and wherein the outlet flow restrictor includes an outlet check valve having an outlet cracking pressure, the outlet check valve being configured to allow fluid flow through the outlet check valve when pressure within the top region is above the outlet cracking pressure.

14. The diaphragm valve according to claim 13, wherein The outlet opening pressure is greater than the atmospheric pressure of the surrounding environment of the diaphragm valve.

15. The diaphragm valve according to claim 14, wherein The outlet check valve has a closing pressure that causes the outlet valve to close, and wherein the pressure in the purge region oscillates between the outlet opening pressure and the closing pressure.

16. The diaphragm valve according to any one of claims 4 to 15, wherein The plungers have an outer surface, and wherein each plunger includes one or more grooves extending along the respective outer surface between the top end of the plunger and the bottom end of the plunger to promote fluid communication between the top region of the inner cavity and the clearing region.

17. The diaphragm valve according to claim 16, wherein The grooves are helical and / or vertically oriented.

18. The diaphragm valve according to any one of claims 2 to 15, wherein The plunger includes a plunger head adapted to engage with the diaphragm, a plunger base adapted to be engaged by one of the upper piston and the lower piston, and a plunger body extending between the plunger head and the plunger base, wherein the plunger head, the plunger base and the plunger body of one or more plungers are independent of each other and are stacked within corresponding plunger channels.

19. The diaphragm valve according to claim 18, wherein The plunger head and the plunger base are substantially rigid, and wherein the plunger body is made of a compressible material, an elastomeric material, or a combination of a compressible material and an elastomeric material.

20. The diaphragm valve according to claim 18, wherein The plunger body includes at least two adjacent portions extending between the plunger head and the plunger base, and wherein each portion has a different compressibility.

21. The diaphragm valve according to claim 18, wherein The plunger body is offset from a central longitudinal axis of the plunger.

22. The diaphragm valve according to claim 18, wherein The plunger base of each plunger is fully seated on a corresponding one of the upper piston and the lower piston.

23. The diaphragm valve according to claim 18, wherein The plunger base of each plunger is fixedly connected to a corresponding one of the upper piston and the lower piston.

24. The diaphragm valve according to any one of claims 2 to 15, wherein The upper piston includes a central bore and a plurality of upper recesses and a plurality of upper protrusions, and wherein the first set of plungers are adapted to seat on the upper protrusions.

25. The diaphragm valve according to claim 24, wherein The lower piston includes a piston head adapted to extend through the central bore of the upper piston, the lower piston including a plurality of lower recesses and a plurality of lower protrusions, wherein the second set of plungers are adapted to seat on the lower protrusions.

26. The diaphragm valve according to claim 25, wherein The central bore and the piston head are shaped in a complementary manner.

27. The diaphragm valve according to claim 25, wherein The upper protrusion is shaped and configured to engage with the lower recess, and wherein the lower protrusion is shaped and configured to engage with the upper recess.

28. The diaphragm valve according to any one of claims 2 to 15, wherein The actuation assembly further includes an activation system including an activation screw configured to selectively apply a force on the lower piston to move the second set of plungers to the closed position.

29. The diaphragm valve according to claim 28, wherein The bottom cover includes a storage mechanism operatively engaged with the actuating screw to indicate a position of the actuating screw.

30. The diaphragm valve according to claim 29, wherein The actuating screw includes recesses distributed around an outer periphery of a head of the actuating screw, and wherein the storage mechanism includes a set screw engageable with the recesses of the actuating screw.

31. A diaphragm valve for gas analysis applications, the diaphragm valve comprising: a valve bonnet provided with a plurality of process conduits extending therethrough, the valve bonnet having a bonnet engagement portion, and each of the process conduits including a process port opening into the bonnet engagement portion; a valve body engageable with the valve cover and having a body engaging portion adapted to face the cover engaging portion and provided with a recess, the valve body including a plurality of plunger channels extending through the valve body whereby the plunger channels open to the recesses; a diaphragm positioned between the bonnet and the valve body and having a process groove for circulating a fluid therein, the process groove being shaped and sized to engage the recess of the valve body; a plunger assembly adapted to be mounted within the valve body, the plunger assembly comprising a plurality of plungers slidably fitted within a corresponding one of the plunger passages, each plunger adapted to selectively engage the diaphragm to control fluid circulation along the process tank; as well as an actuating assembly comprising a gas inlet and an actuating system, wherein the actuating system is configured to enable actuating gas to be injected into the valve body through the gas inlet for actuating the plunger assembly and displacing the plunger, wherein a purge region is defined between the diaphragm and the body joint, and wherein the actuating assembly includes a purge system defining a purge circuit between the gas inlet and the purge region, the purge system being configured to direct the actuating gas from the gas inlet to the purge region for purging the purge region and removing impurities from the purge region.

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