Dual spring valve

Example aspects of a sliding disc assembly for a dual spring valve, and a method of operating a dual spring valve are disclosed. The sliding disc assembly can comprise a shaft defining a first end and a second end; a disc mounted on the shaft between the first end and the second end, the disc defining an upper disc surface, a lower disc surface, and an annular base surface; a first spring mounted on the shaft between the lower disc surface and the first end of the shaft; and a second spring mounted on the shaft between the upper disc surface and the second end of the shaft, wherein the first spring defines a spring force that is different from a spring force of the second spring.

TECHNICAL FIELD

This disclosure relates to piping systems. More specifically, this disclosure relates to a dual spring valve.

BACKGROUND

Air/vacuum valves can be installed with fluid transfer pipelines to alleviate air pockets and to prevent vacuums from forming in the pipeline. Air pockets can be formed when air collects in the pipeline and can slow or stop the flow of fluid in the pipeline. Air collected in the pipe can escape through the air/vacuum valve and can be released into the atmosphere to prevent the formation of air pockets. Further, a vacuum can form in a pipeline when the pipeline is drained and/or when the internal pressure of the pipeline drops below atmospheric pressure. Atmospheric air can enter the pipeline through the air/vacuum valve to prevent the formation of a vacuum.

Commonly, air/vacuum valves comprise a body, a channel extending through the body, and a float positioned within the channel. The channel can define an inlet opening and an outlet opening. When the fluid in a pipeline rises, fluid can enter the channel through the inlet opening. The float can be elevated by the rising fluid towards the outlet opening. The float can block the opening when the fluid reaches a critical level, closing the air/vacuum valve. When the air/vacuum valve is closed abruptly, fluid hammer can occur. The surge of pressure resulting from the abrupt cessation of fluid in motion can create a shock wave within the air/vacuum valve and/or pipeline that can cause damage to the air/vacuum valve and/or pipeline.

A valve can be installed with the air/vacuum valve and pipeline to regulate the flow of fluid into the air/vacuum valve, aiding in the prevention of fluid hammer. The valve can be a check valve or a modified check valve, for example. Check valves often comprise a spring-loaded disc biased away from a seat. When fluid rises into the check valve, pressure is applied to the spring loaded disc, forcing it into engagement with the seat, closing the check valve. Openings can be formed in the disc to allow for a slow and measured flow of fluid into the air/vacuum valve. However, check valves often do not close fast enough to prevent fluid hammer in the air/vacuum valve. Additionally, check valves sometimes slam open or closed, which can result in damage to the check valve.

SUMMARY

It is to be understood that this summary is not an extensive overview of the disclosure. This summary is exemplary and not restrictive, and it is intended neither to identify key or critical elements of the disclosure nor delineate the scope thereof. The sole purpose of this summary is to explain and exemplify certain concepts off the disclosure as an introduction to the following complete and extensive detailed description.

Disclosed is a sliding disc assembly for a dual spring valve, the sliding disc assembly comprising a shaft defining a first end and a second end; a disc mounted on the shaft between the first end and the second end, the disc defining an upper disc surface, a lower disc surface, and an annular base surface; a first spring mounted on the shaft between the lower disc surface and the first end of the shaft; and a second spring mounted on the shaft between the upper disc surface and the second end of the shaft, wherein the first spring defines a spring force that is different from a spring force of the second spring.

Also disclosed is a dual spring valve comprising a valve body, the valve body defining an inlet end, an outlet end, and a cavity extending from the inlet end to the outlet end; a seat body positioned within the cavity and defining a seating surface; and a sliding disc assembly positioned within the cavity, the sliding disc assembly comprising a disc, a first spring, and a second spring, the disc defining a base surface, the sliding disc assembly movable between a first position, wherein the base surface is spaced from the seating surface, and a second position, wherein the base surface seats with seating surface, the second spring biasing the sliding disc assembly towards the first position, and the first spring biasing the sliding disc assembly towards the second position; wherein the dual spring valve is in an open configuration when the sliding disc assembly is in the first position and a closed configuration when the sliding disc assembly is in the second position.

Additionally, a method of operating a dual spring valve is disclosed, the method comprising providing the dual spring valve comprising a valve body defining a cavity and a sliding disc assembly received in the cavity, the sliding disc assembly comprising a first spring, a second spring, and a disc, wherein a spring force of the second spring is greater than a spring force of the first spring; biasing the sliding disc assembly to a first position within the cavity with the second spring, wherein the disc is spaced from a seat body of the dual spring valve in the first position; applying a fluid force to the disc with fluid in the cavity; and biasing the sliding disc assembly to a second position within the cavity with the first spring and the fluid force, wherein a base surface of the disc engages a seating surface of the seat body in the second position.

DETAILED DESCRIPTION

Disclosed in the present application is a dual spring valve and associated methods, systems, devices, and various apparatus. Example aspects of the dual spring valve can comprise a sliding disc assembly configured to seat with a seat body. The sliding disc assembly can comprise a shaft, a disc, and a pair of springs. In some example aspects, the dual spring valve can be a check valve. It would be understood by one of skill in the art that the disclosed dual spring valve is described in but a few exemplary aspects among many. No particular terminology or description should be considered limiting on the disclosure or the scope of any claims issuing therefrom.

FIGS.1and2illustrate a top perspective view and a bottom perspective view of a dual spring valve100, respectively, according to an example aspect of the present disclosure. In the present aspect, the dual spring valve100can be a modified dual spring check valve. As shown, the dual spring valve100can comprise a valve body110. The valve body110can comprise an outer surface112and an inner surface114, and can further define an inlet end116and an outlet end118. The inner surface114can define a cavity120formed through the dual spring valve100, extending from the inlet end116to the outlet end118. A center axis122defined by the valve body110can extend through a center of the cavity120. According to example aspects, the cavity120can define an inlet region224(shown inFIG.2) proximate to the inlet end116, an outlet region126proximate to the outlet end118, and a central region328(shown inFIG.3) extending therebetween. Example aspects of the valve body110can comprise an inlet flange130formed at the inlet end116and an outlet flange134formed at the outlet end118. Each of the inlet and outlet flanges130,134can extend substantially radially outward, relative to the center axis122, from outer surface112of the valve body110, as shown. According to example aspects, the valve body110can be formed from an iron material, such as, for example, ductile iron. Other example aspects of the valve body110can be formed from cast iron, steel, carbon, bronze, another metal material, plastic, or any other suitable material known in the art.

According to example aspects, the dual spring valve100can be attached, connected, or otherwise mounted to a piping system. In the present aspect, the piping system can be configured to transport liquids therethrough, such as water, for example and without limitation. In some aspects, the dual spring valve100can be positioned between a pipe of the piping system and a secondary valve, which can be a quick-close valve in some aspects. For example, in a particular aspect, the secondary valve can be an air/vacuum valve. For example, the inlet flange130of the valve body110can be attached to the pipe and the outlet flange134of the valve body110can be attached to the air/vacuum valve. The piping system and air/vacuum valve can be substantially similar to the piping system and air/vacuum valve disclosed in in U.S. application Ser. No. 16/166,642, filed Oct. 22, 2018, which is hereby specifically incorporated by reference herein in its entirety. In the present aspect, the inlet flange130can define one or more inlet mounting bores132therethrough and the outlet flange134can define one or more outlet mounting bores136therethrough. Inlet fasteners (not shown) can extend through the inlet mounting bores132and can engage the pipe to couple the dual spring valve100to the pipe. Similarly, outlet fasteners (not shown) can extend through the outlet mounting bores136and can engage the secondary valve to couple the dual spring valve100to the secondary valve. Each of the inlet fasteners and outlet fasteners can be any suitable fastener known in the art, including, but not limited to, nut and bolt assemblies, screws, rivets, and the like. In other aspects, the dual spring valve100can be attached to the piping system or the secondary valve by any other suitable attachment mechanisms, such as welding, for example and without limitation.

According to example aspects, the dual spring valve100can be oriented in an open configuration, as shown inFIG.3, and a closed configuration, as shown inFIG.10. The dual spring valve100can be in the open configuration in normal operation, wherein air can be permitted to flow through the cavity120of the dual spring valve100between the piping system and the air/vacuum valve. For example, in forward flow conditions, air from the piping system can flow through the cavity120of the dual spring valve100and into the air/vacuum valve, where it can be released into the atmosphere. Releasing air collected in the piping system can prevent air pockets from forming therein. Air pockets within the piping system can slow the flow of fluid through the piping system or can create an air lock, which can completely stop the flow of fluid through the piping system. Because air tends to collect at high points in the piping system, the dual spring valve100and the secondary valve may be connected to the piping system at a high point thereof in example aspects. In reverse flow conditions, air from the atmosphere can flow into the secondary valve, through the dual spring valve100, and into the piping system. Allowing air to enter the piping system through the dual spring valve100can prevent or reduce the likelihood of a vacuum forming within the piping system when the piping system or a portion thereof is being drained. In the closed configuration, however, air and fluid flow through the dual spring valve100can be limited, allowing only a small amount of flow therethrough at a slow and measured rate. According to example aspects, fluid levels in the piping system can rise and fluid can enter the cavity120of the dual spring valve100. To slow the rate of the fluid passing through the cavity120and into the secondary valve, the dual spring valve100can be provided with a disc140configured to seal the cavity120and prevent fluid flow around the disc140in the closed configuration. The disc can define with one or more small flow openings348(shown inFIG.3) therethrough, which can allow a small amount of gas and/or fluid to flow through the disc140at a slow and controlled rate. Example aspects of the disc140can be formed from a substantially rigid material, such as metal, and can comprise a substantially resilient coating such as, for example, a rubber coating. For example, in a particular aspect, the disc140can be formed from stainless steel and the resilient coating can comprise EPDM rubber. In other aspects, the disc140can be formed from any other suitable rigid material, such as any suitable type of metal, plastic, or composite, and the resilient coating of the disc140can be formed from Buna-N, PTFE, Viton, neoprene, or any other suitable resilient material known in the art.

As also shown inFIG.1, example aspects of the dual spring valve100can comprise an annular seat body150against which the disc140can seat in the closed configuration. The annular seat body150can be positioned generally within the outlet region126of the cavity120, as shown, and proximate to the outlet flange134of the valve body110. In other aspects, the annular seat body150can be positioned elsewhere within the cavity120, such as the central region328(shown inFIG.3). According to example aspects, the annular seat body150can be formed from a resilient material such as, for example, a rubber material, and in some aspects can be formed from EPDM rubber. In other aspects, the annular seat body150can be formed from Buna-N, PTFE, Viton, neoprene, or any other suitable material known in the art. According to example aspects, the annular seat body150can define a substantially cylindrical outer surface352(shown inFIG.3) and a substantially cylindrical inner surface154. The inner surface154can define a seat channel155formed through the annular seat body150, which can be in fluid communication with the cavity120of the valve body110. Furthermore, in the present aspect, a seat vane assembly160can extend substantially radially inward from the seat body150into the seat channel155. The seat vane assembly160can comprise a plurality of seat vanes165, each defining a proximal end166and an opposite distal end168. Each of the seat vanes165can extend substantially radially inward from the inner surface154of the seat body150towards the center axis122at the proximal end166thereof. The distal end168of each seat vane165can be joined with an annular seat guide ring170or seat guide hub, which can define a seat guide bore172therethrough. The seat guide bore172can be substantially concentric with the center axis122, as shown. In the present aspect, the seat vane assembly160can be monolithically formed with the annular seat body150(i.e., the seat vanes165, the seat guide ring170, and the seat body150can define a singular or monolithic component.) In other aspects, however, the seat vane assembly160or portions thereof may be formed separately from the seat body150.

Referring toFIG.2, example aspects of the dual spring valve100can further comprise a body vane assembly260positioned within the cavity120. In the present aspect, the body vane assembly260can be positioned substantially with the inlet region224of the cavity120, as shown. However, in other aspects, the body vane assembly260may be positioned elsewhere within the cavity120, such as within the central region328(shown inFIG.3). The body vane assembly260can comprise a plurality of body vanes265, each defining a proximal end266and an opposite distal end268. Each of the body vanes265can extend substantially radially inward from the inner surface114of the valve body110towards the center axis122at the proximal end266thereof. The distal end268of each body vane265can be joined with an annular body guide ring270or body guide hub, which can define a body guide bore272therethrough. The body guide bore272can be substantially concentric with the center axis122, as shown. In some aspects, such as the present aspect, the body vanes265and the body guide ring270can be monolithically formed with the valve body110, such that the body vane assembly260and valve body110define a singular or monolithic component. In other aspects, however, the body vane assembly260or portions thereof can be formed separately from the valve body110. According to example aspects, the body vane assembly260and seat vane assembly160can be configured to reduce the turbulence of air and/or fluid flowing through the cavity120.

FIG.3illustrates a sectional view of the dual spring valve100, showing various components received in the cavity120thereof. As shown, a diameter of the cavity120at the inlet and outlet region224,126can be substantially equal in some aspects. Furthermore, in various example aspects, a diameter of the cavity120at the central region328can be greater than the diameter of the cavity120at the respective inlet and outlet regions224,126, as shown. As described above, the annular seat body150can be received within the outlet region126of the cavity120. The seat body150can define the inner surface154and the outer surface352, and can further define a first end354and an opposite second end356. In example aspects, a substantially annular seating surface355can be defined at the first end354and can extend between the inner surface154and the outer surface352. The disc140can be configured to seat with the annular seating surface355in the closed configuration, as described in further detail below. The inner surface154of the seat body150can define the seat channel155extending from the first end354to the second end356, and the outer surface352of the seat body150can engage the inner surface114of the valve body110. In some aspects, one or more bearings302can be provided for retaining the seat body150in position within the cavity120. For example, as shown, the bearings302can be ball bearings304, and each of the ball bearings304can be received within a corresponding bearing bore305of the seat body150. As shown, the bearing bores305can extend into the seat body150at the second end356thereof. Furthermore, a bearing opening307can be formed in the outer surface352of the seat body150proximate to each of the bearing bores305, and each bearing opening307can meet the corresponding one of the bearing bores305. Each of the ball bearings305can extend partially through the corresponding bearing opening307defined in the outer surface352of the seat body150to engage the inner surface114of the valve body110. A fastener, such as a set screw306, as shown, can be received within each of the bearing bores305to retain the corresponding ball bearing304therein. Furthermore, in some aspects, the set screws306can be tightened against the corresponding ball bearings304to push the corresponding ball bearings304further through the corresponding bearing openings307. Thus, as the set screws306are tightened, the ball bearings304can be increasingly pressed against the inner surface114of the valve body110. The engagement of the ball bearings304with the inner surface114can retain the seat body150in position relative to the valve body110. In other aspects, any other suitable fastener can be provided for retaining each of the ball bearings304in the corresponding bearing bores305and/or pushing the ball bearings304into the corresponding bearing openings307.

As shown, the seat vanes165of the seat vane assembly160can extend substantially radially inward from the inner surface154of the seat body150to the seat guide ring170. The seat guide ring170can define the seat guide bore172. In some example aspects, the seat vanes165can be angled towards the inlet end116, as shown. In other aspects, however, the seat vanes165may be angled toward the outlet end118, or may not be angled towards either of the inlet or outlet ends116,118. Furthermore, as shown, the body vanes265of the body vane assembly260can extend substantially radially inward from the inner surface114of the valve body110at the inlet region224of the cavity120to the body guide ring270. The body guide ring270can define the body guide bore272therethrough. In some aspects, a bushing325can be mounted to the body guide ring270and can define a bushing bore825(shown inFIG.8), as described in further detail below.

According to example aspects, the dual spring valve100can comprise a sliding disc assembly310positioned within the cavity120and supporting the disc140therein. The sliding disc assembly310can comprise a shaft312slidably mounted within the cavity120and extending substantially along and aligned with the center axis122. The sliding disc assembly310can further comprise the disc140mounted on the shaft312, a first biasing element320mounted on the shaft312, and a second biasing element324mounted on the shaft312. Example aspects of the shaft312can generally define an elongate cylindrical shape having a first end314oriented proximate the inlet region224and an opposite second end316oriented proximate the outlet region126. The sliding disc assembly310can be configured to slide axially within the cavity120, substantially along the center axis122, between a first position and a second position. Thus, the first end314of the shaft312can slidably engage the body guide bore272of the body guide ring270and the second end316of the shaft312can slidably engage the seat guide bore172of the seat guide ring170. In the first position, the dual spring valve100can be in the open configuration, as shown, and in the second position, the dual spring valve100can be in the closed configuration.

According to example aspects, the first biasing element320can comprise a first spring322configured to aid in biasing the dual spring valve100to the closed configuration, and further configured to slow the movement of the dual spring valve100from the closed configuration to the open configuration. Similarly, the second biasing element324can be a second spring326configured to aid in biasing the dual spring valve100to the open configuration, and further configured to slow the movement of the dual spring valve100from the open configuration to the closed configuration. Each of the first and second springs322,326can comprise a compression spring in the present aspect, but in other aspects, either or both of the first and second springs322,326can be any other suitable type of spring known in the art. Slowing the movement of the dual spring valve100between the open and closed configurations can allow for smoother, more controlled operation. It can also be particularly beneficial to slow the movement of the dual spring valve100to the closed configuration to prevent damage that can occur when the dual spring valve100closes.

As shown, the first spring322can be mounted on the shaft312and can extend between the disc140and the body vane assembly260. More specifically, in example aspects, the first spring322can extend between a lower disc surface342of the disc140and the bushing325. The first spring322can bias the disc140away from the body vane assembly260and towards the seat body150, and thus, towards the closed configuration. The first spring322can be substantially cylindrical in the present aspect, but can define any other suitable shape in other aspects. The second spring326can also be mounted on the shaft312and can extend between the disc140and the seat vane assembly160. More specifically, the second spring326can extend between an upper disc surface344of the disc140and the seat vanes165. In the present aspect, the second spring326can substantially define the shape of a truncated cone. That is to say, the second spring326can define a spring diameter that can taper along a length thereof. For example, in the present aspect, the spring diameter of the second spring326can taper towards the disc140, such that the spring diameter of the second spring326proximate to the disc140can be less than the spring diameter of the second spring326proximate to the seat vane assembly160. In other aspects, the second spring326can define any other suitable shape.

The sliding disc assembly310can further comprise the disc140mounted to the shaft312. The disc140can be positioned on the shaft312between the first and second springs322,326, and thus between the body and seat vane assemblies270,160. According to example aspects, the disc140can be substantially bowl-shaped. For example, as shown, the disc140can define the lower disc surface342and the upper disc surface344, each of which can be substantially hemispherical, and an annular base surface346extending therebetween. The annular base surface346can face towards the annular seating surface355of the seat body150and can be configured to seat with the annular seating surface355in the closed configuration of the dual spring valve100. In example aspects, the disc140may also define one or more flow openings348extending from the lower disc surface342to the upper disc surface344, which can allow gas and/or fluid to flow therethrough at a slow, controlled rate. Example aspects of the disc140can also define a central opening560(shown inFIG.5) therethrough, through which the shaft312can extend to mount the disc140on the shaft312. The central opening560can be substantially concentric to the center axis122.

In some aspects, an upper flange362can extend from the upper disc surface344of the disc140and can surround the central opening560, as shown. The upper flange362can reinforce the disc140at the central opening560, and may also aid in positioning the second spring326relative to the disc140, as described in further detail with respect toFIG.6. Similarly, in some aspects, a lower flange364can extend from the lower disc surface342of the disc140and can surround the central opening560. The lower flange364can further reinforce the disc140at the central opening560, and may aid in positioning the first spring322relative to the disc140, as described in further detail with respect toFIG.8. According to example aspects, the reinforcement provided by each of the upper and lower flanges362,362can aid in maintaining the proper orientation of disc140, by preventing undesirable bending, folding, or twisting of the disc140at or near the central opening560. Additionally, as described above, the first and second springs322,326can engage the lower and upper disc surfaces342,344of the disc140, respectively, thus sandwiching the disc140therebetween and further aiding in maintaining the proper orientation of the disc140.

In example aspects, the second spring326can define a spring force that can be greater than a spring force of the first spring322. The spring force of the second spring326can overcome that of the first spring322to expand the second spring326between the seat vane assembly160and the upper disc surface344, and to compress the first spring322between the lower disc surface342and the body vane assembly260. As the second spring326is expanded and the first spring322is compressed, the shaft312and the disc140can be biased away from the seat body150and towards the inlet end116of the dual spring valve100, thus naturally orienting the sliding disc assembly310in the first position and the dual spring valve100in the open configuration, as shown. As described above, the shaft312can be configured to slide within the seat guide bore172of the seat guide ring170and the body guide bore272of the body guide ring270to allow for movement of the sliding disc assembly310between the first and second positions. As shown, with the sliding disc assembly310in the first position and the dual spring valve100in the open configuration, the disc140can be spaced from the seat body150and can be oriented within the central region328of the cavity120. The disc140and the central region328can be sized such that air can flow around the disc140and through the cavity120from the inlet end116to the outlet end118, or vice versa. Air can also flow through the flow openings348formed in the disc140. Thus, in a particular aspect, in the open configuration, air from the piping system can be released into the atmosphere through the dual spring valve100to prevent the formation of air pockets in the piping system. Furthermore, in the open configuration, air from the atmosphere can be admitted to the piping system through the dual spring valve100to prevent the formation of a vacuum in the piping system.

FIG.4illustrates the shaft312, according to an example aspect of the present disclosure. As shown, the shaft312generally defines the elongate cylindrical shape generally defining a shaft diameter D. The shaft312also defines the first end314and the opposite second end316. According to example aspects, a disc portion412of the shaft312can be positioned at a location along the shaft312between the first and second ends314,316thereof and can be configured to extend through the central opening560(shown inFIG.5) formed through the disc140(shown inFIG.3). In some aspects, the disc portion412of the shaft312can define an increased diameter as compared to the shaft diameter D. Various aspects of the shaft312can also define a bearing journal414oriented adjacent to the disc portion412and positioned along the shaft312between disc portion412and the first end314. In some aspects, the bearing journal414can define an increased diameter as compared to the shaft diameter D, and also as compared to the diameter of the disc portion412, as shown. As such, the bearing journal414can define an annular first shoulder416distal to the disc portion412and an annular second shoulder418proximate to the disc portion412. In the first position of the sliding disc assembly310(shown inFIG.3) (i.e., in the open configuration of the dual spring valve100, as shown inFIG.3), the bearing journal414can be configured to extend between the lower disc surface342(shown inFIG.3) of the disc140and the bushing325(shown inFIG.3). The first shoulder416can abut the bushing325in the first position to prohibit the shaft312from advancing further through the body guide bore272(shown inFIG.2) of the body guide ring270(shown inFIG.2). In the second position of the sliding disc assembly310, the shaft312can slide axially away from the bushing325, and the bearing journal414thereof can disengage the bushing325. In some aspects, the bearing journal414can further define one or more recessed regions420formed therein; however, other aspects may not define the recessed regions420.

FIG.5illustrates a top perspective view of the disc140. As shown, the disc140defines the substantially hemispherical lower disc surface342and the substantially hemispherical upper disc surface344. The annular base surface346of the disc140extends about and between the circumferences of the lower and upper disc surfaces342,344. The base surface346can be substantially planar, as shown. Furthermore, the central opening560can extend through the disc140generally at a center thereof. The central opening560can be sized to receive the disc portion412(shown inFIG.4) of the shaft312(shown inFIG.4) therethrough. The upper flange362can project from the upper disc surface344and can encircle the central opening560. Similarly, the lower flange364(shown inFIG.3) can project from the lower disc surface342and can encircle the central opening560. As such, in example aspects, the upper and lower flanges362,364can be configured to substantially surround the disc portion412when the disc140is mounted on the shaft312. Additionally, the flow openings348can be formed through the disc140, extending from the upper disc surface344to the lower disc surface342thereof. The flow openings348can allow the passage of air or fluid therethrough in both the open and closed configurations of the dual spring valve100(shown inFIG.1).

FIG.6illustrates a top perspective view of the sliding disc assembly310. As shown, the disc140can be mounted on the shaft312. Moreover, the first spring322can be mounted on the shaft312and can extend from the lower disc surface342of the disc140towards the first end314of the shaft312, and the second spring326can be mounted on the shaft312and can extend from the upper disc surface344of the disc140towards the second end316of the shaft312. Example aspects of the first spring322can define a lower spring end622proximate to the first end314of the shaft312and an upper spring end824(shown inFIG.8) proximate to the disc140. In the present aspect, the first end314of the shaft312is illustrated extending through the bushing bore825(shown inFIG.8) of the bushing325. The bushing325can comprise a bushing body630, which can define the bushing bore825therethrough, and a bushing flange635extending radially outward from the bushing body630. A portion of the bushing body630can extend into the first spring322at the lower spring end622thereof, and the lower spring end622can abut the bushing flange635, as described in further detail below. Example aspects of the second spring326can define a lower spring end626oriented proximate to the disc140and an upper spring end628proximate to the second end316of the shaft312. The spring diameter of the second spring326can taper from the upper spring end628to the lower spring end626, as shown. In example aspects, the upper flange362can extend into the second spring326at the lower spring end626thereof, thereby preventing or limiting lateral movement of the second spring326relative to the disc140.

FIG.7illustrates the engagement of the sliding disc assembly310with the seat vane assembly160. As shown, in the present aspect, the seat vane assembly160can be monolithically formed with the annular seat body150. The seat vane assembly160can comprise the seat vanes165and the seat guide ring170, wherein the seat vanes165can extend radially inward from inner surface154of the seat body150to join with the seat guide ring170. The second end316of the shaft312can slidably engage the seat guide bore172(shown inFIG.1) of the seat guide ring170, and can move axially therein as the sliding disc assembly310moves between the first and second positions. As shown, the second spring326can be mounted on the shaft312, and the upper spring end628thereof can abut the seat vane assembly160. For example, in the present aspect, the upper spring end628of the second spring326end can engage each of the seat vanes165. The lower spring end626(shown inFIG.6) of the second spring326can engage the upper disc surface344(shown inFIG.3) of the disc140(shown inFIG.3), as described above.

FIG.8illustrates a bottom perspective view of the sliding disc assembly310. The bushing325is also illustrated, with the first end314of shaft312extending slidably through the bushing bore825thereof. As shown, the disc140and the first spring322can be mounted on the shaft312. In example aspects, the disc portion412(shown inFIG.4) of the shaft312can be received through the central opening560(shown inFIG.3) of the disc140, and the bearing journal414of the shaft312can be oriented proximate to, and in some instances can engage, the lower disc surface342of the disc140. For example, in the present aspect, the second shoulder418(shown inFIG.4) of the bearing journal414can abut the lower flange364of the lower disc surface342of the disc140. As shown, the first spring322can define the upper spring end824and the lower spring end622. The upper spring end824can engage the lower disc surface342and can extend from the lower disc surface342of the disc140towards the first end314of the shaft312. In the present aspect, the upper spring end824can abut the lower flange364extending from the lower disc surface342of the disc140. As such, as shown, the bearing journal414of the shaft312can extend within the first spring322at the upper spring end824. In other aspects, the lower flange364may also be configured to extend within the first spring322at the upper spring end824thereof.

As shown, the bushing325can define the bushing body630and the bushing flange635extending radially therefrom. The bushing body630can define the bushing bore825, as shown, and the first end314of the shaft312can extend slidably therethrough. The bushing body630can further define an upper body portion832extending from bushing flange635towards the disc140and a lower body portion834extending from the bushing flange635away from the disc140. In example aspects, as shown, the upper body portion832of the bushing body630can be configured to extend into the first spring322at the lower spring end622thereof, and the lower spring end622can abut the bushing flange635. As such, as the sliding disc assembly310moves between the first and second positions (i.e., the dual spring valve100ofFIG.1moves between the open and closed configurations, respectively), the first spring322can be expanded and compressed between the disc140and the bushing flange635. According to example aspects, the size of the bearing journal414of the shaft312and the upper body portion832of the bushing325extending through the first spring322can be configured to prohibit or limit lateral movement of the first spring322. In example aspects, the lower body portion834of the bushing325can engage the body guide bore272(shown inFIG.2) of the body guide ring270(shown inFIG.2) to mount the bushing325on the body guide ring270, as shown and described in further detail with respect toFIG.9.

FIG.9illustrates a detail cross-sectional view of the engagement of the sliding disc assembly310with the body vane assembly260. As shown, the body vane assembly260can comprise the body vanes265joined with the body guide ring270, and the body guide ring270can define the body guide bore272therethrough. The bushing325can define the bushing body630and the bushing flange635, and the bushing body630can define the upper body portion832and the lower body portion834. As shown, the lower body portion834of the bushing325can extend into the body guide bore272, and the bushing flange635can abut an upper ring end972of the body guide ring270. Each of the bushing bore825and the body guide bore272can be substantially concentric with the center axis122. The first end314of the shaft312can extend into the bushing bore825at the upper body portion832, and can extend at least partially through the body guide bore272, as shown. According to example aspects, the shaft312can be slidably engaged with the bushing bore825and body guide bore272, such that the shaft312can move axially therein as the sliding disc assembly310moves between the first and second positions. In example aspects, in the first position of the sliding disc assembly310, the first shoulder416of the bearing journal414of the shaft312can abut an upper body end932of the upper body portion832of the bushing325to limit the axial movement of the shaft312through the bushing bore825and body guide bore272. Furthermore, as shown, the upper body portion832of the bushing body630can extend into the first spring322at the lower spring end622thereof, and the lower spring end622can abut the bushing flange635. The opposite upper spring end824(shown inFIG.8) of the first spring322can engage the lower disc surface342(shown inFIG.8) of the disc140(shown inFIG.8), as described above.

FIG.10illustrates the sliding disc assembly310in the second position and the dual spring valve100in the closed configuration. As described above, in normal operation, the dual spring valve100can be in open configuration and air can be permitted to flow through the cavity120. The spring force of the second spring326can be greater than the spring force of the first spring322, and can thus bias the sliding disc assembly310to the first position, as shown inFIG.3. However, in abnormal conditions, fluid levels in the piping system can rise, and fluid can enter the cavity120of the dual spring valve100at the inlet region224. The fluid can rise within the cavity120generally from the inlet region224towards the outlet region126. According to example aspects, the rising fluid (or a rush of air resulting from the rising fluid) can apply pressure (i.e., a fluid force) to the lower disc surface342of the disc140generally in the axial direction, as indicated by directional arrow P. In certain conditions, the pressure applied to the disc140can be great enough to overcome the spring force of the second spring326to bias the sliding disc assembly310towards the outlet end118and compress the second spring326between the disc140and the seat vane assembly160. For example, in conditions where the flow of fluid into the cavity120is rapid and/or turbulent, the pressure can be great enough to overcome the spring force of the second spring326. In example aspects, the spring force of the first spring322can also aid in biasing the sliding disc assembly310towards the outlet end118. As the sliding disc assembly310is biased towards the outlet end118, the sliding disc assembly310can move from the first position, wherein the dual spring valve100is in the open configuration, to the second position, as shown, wherein the dual spring valve100is in the closed configuration.

According to exampling aspects, the spring force of the second spring326can provide some resistance as the sliding disc assembly310moves towards the second position, thus preventing the dual spring valve100from slamming closed. It can be desirable to prevent the dual spring valve100from slamming closed, as damage can occur to the dual spring valve100during a forceful closure. However, it can also be desirable to quickly close the dual spring valve100before fluid can flow around the disc140, and the spring force of the first spring322can aid in quickly closing the dual spring valve100as the fluid rises in the cavity120. Furthermore, in turbulent flow conditions, the body vanes265and/or seat vanes165can aid in reducing the turbulence of the fluid as it flows through the cavity120. Fluid turbulence can cause vibrations that can result in failure of the dual spring valve100and/or the air/vacuum valve (shown inFIG.7). Thus, reducing the turbulence of the fluid can reduce the likelihood of valve failure. In other instances, however, the pressure applied to the disc140can be minimal. For example, the pressure resulting from a slow and/or gentle flow of fluid into the cavity120may not be great enough to overcome the spring force of the second spring326, and the dual spring valve100can remain in the open configuration.

When the pressure applied to the disc140by the rising fluid (or a rush of air), in combination with the spring force of the first spring322, is greater than the spring force of the second spring326, the sliding disc assembly310can be slid axially towards the outlet end118of the dual spring valve100from the first position to the second position. The first end314of the shaft312can slid within the bushing bore825and the body guide bore272, and the second end316of the shaft312can slide within the seat guide bore172. The first spring322can be expanded between the bushing325and the lower disc surface342of the disc140, and the second spring326can be compressed between the seat vane assembly160and the upper disc surface344of the disc140. According to example aspects, as shown, a tapered portion1014of the inner surface114of the valve body110can taper towards the annular seat body150, such that the diameter of the cavity120at the tapered portion1014can gradually decrease towards the outlet region126. Thus, as the sliding disc assembly310moves towards the second position and the disc140moves towards the seat body150, a clearance between the inner surface114and the disc140can be gradually reduced. As the clearance is reduced, the rate of air and/or fluid flow around the disc140can be diminished. In the second position of the sliding disc assembly310, the annular base surface346of the disc140can engage the annular seating surface355of the seat body150to create a seal therebetween, thus preventing the fluid from flowing around the disc140and orienting the dual spring valve100in the closed configuration. According to example aspects, the spring force of each of the first and second springs322,326can be selected as desired, and can determine the amount of pressure required to overcome the spring force of the second spring326and to move the sliding disc assembly310from the first position to the second position.

With the dual spring valve100in the closed configuration and fluid prevented from flowing around the disc140, a limited amount of fluid can continue to flow through the flow openings348(shown inFIG.3) formed through the disc140at a slow and measured rate. Slowing and controlling the rate at which fluid enters the air/vacuum valve, or other secondary valve, can prevent fluid hammer (e.g., water hammer) from occurring in the air/vacuum valve. Fluid hammer can occur when the air/vacuum valve abruptly closes, which can cause the fluid flowing into the air/vacuum valve to stop abruptly. The surge of pressure resulting from the abrupt cessation of the fluid can create shock waves within the air/vacuum valve and/or piping system that can cause damage to the air/vacuum valve and/or piping system. Thus, the dual spring valve100can aid in preventing such fluid hammer.

Once the flow of fluid from the piping system into the dual spring valve100slows, the pressure on either side of the disc140can begin to equalize. Once the pressure biasing the sliding disc assembly310to the second position can no longer overcome the spring force of the second spring326, the second spring326can bias the sliding disc assembly310back to the first position, thus reorienting the dual spring valve100in the open configuration. According to example aspects, the spring force of the first spring322can provide some resistance as the sliding disc assembly310moves back to the first position, thus preventing the dual spring valve100from slamming open and reducing the likelihood of damage occurring to the dual spring valve100upon opening. As the fluid level in the piping system drops, fluid in the air/vacuum valve can flow back through the cavity120of the dual spring valve100from the outlet region126to the inlet region224and back into the piping system. Air can then once again flow between the piping system and the air/vacuum valve, as needed.

Thus, according to example aspects, a method of operating the dual spring valve100can comprise providing the dual spring valve100, wherein the dual spring valve100can comprise the valve body110defining the cavity120and the sliding disc assembly310received in the cavity. The sliding disc assembly310can comprise the first spring322, the second spring326, and the disc140, wherein the spring force of the second spring326can be greater than the spring force of the first spring322. The method can also comprise biasing the sliding disc assembly310to the first position within the cavity120with the second spring326, wherein the disc140can be spaced from the seat body150in the first position. The method can further comprise applying a fluid force to the disc140as the fluid rises with the cavity120and biasing the sliding disc assembly310to the second position within the cavity120with the first spring322and the fluid force. The base surface346of the disc140can engage the seating surface355of the seat body150in the second position.