CALIBRATED FLOW SENSING AND FLOW CONTROL DEVICE

Abstract

Fluid flow sensors, which may also be the basis of valves for fire suppression systems, use a sensing arm to communicate movement of an obturator or valve closure member to a sensor system that evaluates the movement and, if warranted, generates a calibrated measure of flow and / or an alarm signal in response. The obturator and valve closure members are capable of both rotational and translational movement, both of which are sensed using the sensing arm. The sensor system is isolated from the fluid within the valve.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of priority to U.S. Provisional Application No. 63 / 212,209, filed June 18, 2021, which is incorporated herein by reference.

[0002] (Technical field) The present invention relates to a flow sensor for measuring fluid flow and a valve for controlling fluid flow. [Background technology]

[0003] Prior art flow sensors are limited in their sensitivity at low flow rates, especially at low flow rates through relatively large diameter pipe elements. There is room for improving the accuracy and sensitivity of flow sensors.

[0004] Check valves, particularly those used in fire suppression systems, maintain water or gas within the system's piping network and allow water flow from a pressurized source into the system when one or more sprinklers open in response to a fire. Local and national building codes often require check valves to be used with associated flow sensors, which can initiate an alarm, such as an audible alarm at the fire scene and an electronic communication signal to the local fire department notifying them that a fire has occurred at a particular location. Practical designs for such check valves, particularly swinging clapper-type check valves, often employ valve elements with a limited range of unconstrained (or "lost" motion) to prevent the valve from leaking due to the complexity of ensuring that the clapper seal plane is consistently aligned with the clapper seat plane under all manufacturing tolerances, testing, and operating conditions to naturally form a good seal under varying practical conditions.

[0005] Prior art check valves, particularly those used in systems maintaining water downstream of the check valve, are often installed adjacent to a flow switch in the form of a paddle within the flow stream flowing through the valve, because the unpredictable lost motion of the valve element makes the valve element unsuitable for repeatable use as a flow indicator. Furthermore, standards and specifications governing the certification of such flow switches for use (such as those provided by UL) require that the flow switch must not activate below a certain flow threshold (typically 4 gallons per minute (GPM)) but must not fail to activate below 10 GPM. To meet this requirement across the range of common sizes of pipe in which such flow switches and check valves are installed, switches with matching paddles for each size of pipe are employed. The position of the paddle in response to flow rate through the valve within the standards imposed by regulations triggers a microswitch to initiate an alarm. However, such systems are delicate and cannot withstand high flow rates or high pressure flows, thus limiting the rate at which water can fill the piping network volume. Paddles also cause increased resistance to flow and a measurable loss of pressure head through the pipe. Because the paddles are in the flow stream and mechanically connected to a dedicated external control box enclosure that houses a microswitch, draining the entire system is necessary to effect adjustment, repair, or replacement. Regulations prohibit the use of paddle flow switches when such check valves are installed in systems with pressurized air or other gas downstream of the check valve. Check valves in such systems, commonly referred to as dry, pre-acting, or all-at-once systems, cannot use paddle flow switches and are instead made significantly more complex by using an intermediate chamber between the pressurized water supply upstream of the check valve and the pressurized air or gas in the system downstream of the check valve. This intermediate chamber is connected to a separate water flow pressure switch that is used to monitor the check valve's opening by detecting the pressure increase in the intermediate chamber due to the check valve opening. Clearly, there is room for improvement in check valves, including those used in fire protection systems, and the systems in which they are installed. Summary of the Invention [Means for solving the problem]

[0006] In one aspect, the present invention relates to a flow sensor. In one exemplary embodiment, the flow sensor includes a housing having an inlet and an outlet. The housing defines a flow path between the inlet and the outlet. A shaft is rotatably mounted within the housing. An obstruction is positioned within the housing between the inlet and the outlet. The obstruction is mounted on the shaft and is movable relative to the shaft and relative to the housing in response to fluid flow between the inlet and the outlet. A sensing arm has a first end fixedly mounted on the shaft and a second end that engages the obstruction. A sensor system adapted to sense rotation of the shaft relative to the housing is a further part of the exemplary embodiment.

[0007] By way of example, the closure includes a disk oriented transversely to the flow path. In an exemplary embodiment, the closure may further include at least one lug extending between the disk and the shaft. The lug defines a hole that receives the shaft. The hole is sized to allow rotational and translational movement of the disk relative to the shaft. The exemplary flow sensor may further include a seat surrounding the inlet. The closure is engageable with the seat. A spring acts between the closure and a protrusion extending from the housing or the sensor system into the housing to bias the closure into engagement with the seat. An exemplary embodiment may include a protrusion extending from the sensor system into the housing, the spring acting between the protrusion and the sensing arm. The protrusion may have an eccentric cross-section.

[0008] An exemplary flow sensor according to the present invention may include a seal positioned between the seat and the occlusion and mounted on one of the seat or the occlusion. Further, by way of example, a weight may be mounted on the sensing arm distal to the shaft. A linkage may extend between the sensing arm and the occlusion. The linkage is positioned distal to the shaft for flexibly connecting the sensing arm to the occlusion.

[0009] In an exemplary embodiment, an actuator may be used to move the sensing arm. In one example, the actuator includes a push rod having a first end extending from the housing and a second end engageable with the sensing arm proximate the shaft, the push rod defining an eccentric line of action relative to the shaft, thereby allowing a force applied to the push rod to rotate the sensing arm about the shaft. The actuator may further include a solenoid adapted to move the push rod. In another exemplary embodiment, the actuator includes a shaft having a first end protruding from the housing and a second end positioned within the housing proximate the shaft. A cam is mounted on the second end of the shaft. The cam is rotatable to engage and disengage with the sensing arm upon rotation of the shaft to effect rotation of the sensing arm and the shaft. Further, by way of example, an electric motor may be engaged with the shaft and adapted to rotate the shaft to rotate the cam.

[0010] In another exemplary embodiment, the actuator includes a lever arm attached to a first end of a shaft, the lever arm extending transversely to the shaft, and a solenoid adapted to engage the lever arm and move the lever arm, thereby rotating the shaft.

[0011] An exemplary flow sensor may include a magnet fixedly mounted on the shaft. The magnet is positioned proximate to the sensor system. In exemplary embodiments, the magnet is positioned within the housing. In particular examples, the magnet is mounted on the end of the shaft. In some examples, the magnet is surrounded by a non-magnetic sheath protruding from the housing, and the sensor system is positioned on the exterior of the housing. The sensor system may include a non-contact sensor, e.g., a sensor selected from the group consisting of a magnetic sensor, a Hall effect sensor, and a capacitive sensor. In exemplary embodiments, the sensor system includes a magnetic position sensor. By way of example, the sensor system may further include a controller in communication with the magnetic position sensor. In another example, the sensor system includes an adjustable delay circuit in communication with the controller for delaying communication of an alarm signal from the controller.

[0012] In another aspect, the invention relates to a valve. In an exemplary embodiment, the valve includes a housing having an inlet and an outlet. A seat surrounds the inlet. A shaft is rotatably mounted within the housing. A valve closure member is positioned within the housing and sealingly engageable with the seat. The valve closure member is mounted on the shaft and movable relative to the shaft between an open position that allows flow from the inlet to the outlet and a closed position that prevents reverse flow. A sensing arm has a first end fixedly mounted on the shaft and a second end portion that engages the valve closure member. A spring operates to bias the sensing arm into contact with the valve closure member. A sensor system is adapted to sense rotation of the shaft relative to the housing.

[0013] In an exemplary embodiment, the spring acts between the housing and the sensing arm. Another example includes a protrusion extending from the sensor system into the housing. The spring acts between the protrusion and the sensing arm. The spring acts to bias the valve closure member to the closed position. By way of example, the sensor system may be mounted on the housing. The protrusion may have an eccentric cross-section.

[0014] In an exemplary embodiment, the sensing arm includes a first protrusion extending from the second end portion and a second protrusion extending from the second end in a spaced relationship relative to the first protrusion. The first and second protrusions engage the valve closure member. In an exemplary embodiment, the first and second protrusions are aligned along a line oriented parallel to the shaft.

[0015] In an exemplary embodiment, the valve closure member includes a disk sealingly engageable with the seat. A first lug projects from the disk. The first lug defines a first opening for receiving the shaft. A second lug projects from the disk. The second lug is disposed in a spaced-apart relationship with the first lug and defines a second opening for receiving the shaft. The disk is rotatable about and relative to the shaft. In an exemplary embodiment, the first and second openings include respective first and second slots. The first and second slots are oriented relative to the disk to permit translational movement of the disk toward and away from the seat.

[0016] In an exemplary embodiment, the sensing arm includes a first protrusion extending from the second end portion and a second protrusion extending from the second end portion, positioned in a spaced relationship relative to the first protrusion. The first and second protrusions engage the valve closure member. For example, the first and second protrusions are aligned along a line oriented parallel to the shaft. The first protrusion engages the disc on one side of a diameter line of the disc, and the second protrusion engages the disc on the opposite side of the diameter line. The diameter line is oriented perpendicular to the shaft. In a further example, the second end portion of the sensing arm extends in a direction parallel to the shaft, and the first and second protrusions engage the disc at first and second points proximate the center of the disc. The first and second points may be located beyond the center of the disc relative to the shaft.

[0017] In an exemplary embodiment, the magnet is fixedly mounted on the shaft. The magnet is positioned proximate to the sensor system. By way of example, the magnet may be positioned within the housing and mounted on the end of the shaft. In an exemplary embodiment, the magnet is surrounded by a non-magnetic sheath that protrudes from the housing. By way of example, the sensor system may be positioned on the exterior of the housing.

[0018] In an exemplary embodiment, the sensor system includes a non-contact sensor. For example, the sensor system may include a sensor selected from the group consisting of a magnetic sensor, a Hall effect sensor, and a capacitive sensor. The exemplary sensor system may include a magnetic position sensor. In a further example, the sensor system may include a controller in communication with the magnetic position sensor. The exemplary system may further include an adjustable delay circuit in communication with the controller for delaying communication of the alarm signal from the controller.

[0019] The present invention further encompasses a method of detecting fluid flow through a valve. In an exemplary embodiment, the valve includes a valve housing. The valve housing defines a seat. A valve closure member is positioned within the valve housing, sealingly engaged with the seat, and movable between a closed position that prevents fluid flow and an open position that allows fluid flow. An exemplary embodiment of a method according to the present invention includes using a sensing arm mounted on the housing and engaged with the valve closure member to sense movement of the valve closure member between the closed and open positions.

[0020] In an exemplary method, sensing movement of the valve closure member may include sensing rotation of a sensing arm, the rotation of the sensing arm sensing rotational movement of the valve closure member. Further by way of example, the rotation of the sensing arm sensing translational movement of the valve closure member.

[0021] In an exemplary embodiment, the sensing arm may be fixedly mounted on a shaft, which is rotatably mounted on the housing, and sensing rotation of the sensing arm, in this example, includes sensing rotation of the shaft relative to the valve housing.

[0022] An exemplary method according to the present invention further includes calibrating the valve. In a specific exemplary embodiment, calibrating the valve includes: causing a fluid to flow through a valve at a known rate; determining the position of the sensing arm while the fluid is flowing at a known rate; Correlating the position of the sensing arm to a known fluid flow rate; Includes.

[0023] Another example of calibrating a valve is flowing a fluid through a valve at a first known rate; determining a first position of the sensing arm while the fluid is flowing at a first known rate; Associating a first known rate of fluid flow with a first position of the sensing arm; flowing the fluid through the valve at a second known rate different from the first known rate; determining a second position of the sensing arm while the fluid is flowing at a second known rate; Associating a second known rate of fluid flow with a second position of the sensing arm; Includes.

[0024] In a practical example, the first and second known rates of fluid flow range from 4 gallons (15 liters) per minute to 10 gallons (38 liters) per minute.

[0025] The present invention further includes a fire suppression sprinkler system connectable to a water supply. In an exemplary embodiment, the sprinkler system includes a standpipe connectable to the water supply and a plurality of fire suppression sprinklers. A piping network provides fluid communication between the standpipe and the sprinklers. A check valve controls fluid flow between the standpipe and the piping network. Illustratively, the check valve includes a housing having an inlet connected to the standpipe and an outlet connected to the piping network. A seat surrounds the inlet. A shaft is rotatably mounted within the housing. A valve closure member is positioned within the housing and sealingly engageable with the seat. The valve closure member is mounted on the shaft and movable relative to the shaft between an open position that allows flow from the inlet to the outlet and a closed position that prevents reverse flow. A sensing arm has a first end fixedly mounted on the shaft and a second end portion that engages the valve closure member. A spring is operative to bias the sensing arm into contact with the valve closure member. A sensor system is adapted to sense rotation of the shaft relative to the housing.

[0026] An exemplary fire suppression system according to the present invention may further include a shut-off valve for controlling fluid flow to a valve positioned between the check valve and the standpipe. By way of example, the shut-off valve may be positioned within the housing between the inlet and the valve closure member.

[0027] In an exemplary system, the check valve is calibrated by relating known rates of fluid flow to the rotational position of the shaft. In a practical example, the check valve is calibrated to detect a fluid flow range of 4 gallons per minute (15 liters / minute) to 10 gallons per minute (38 liters / minute).

[0028] The exemplary fire suppression system may further include a test drain valve in fluid communication with the check valve at a location between the valve closure member and the outlet. Further, by way of example, a pressure gauge may be positioned in fluid communication with the check valve at a location between the valve closure member and the outlet. A pressure valve may also be positioned in fluid communication with the check valve at a location between the valve closure member and the outlet. The present specification also provides, for example, the following: (Item 1) A flow sensor, the flow sensor comprising: a housing having an inlet and an outlet, the housing defining a flow path between the inlet and the outlet; a shaft rotatably mounted within the housing; an obturator positioned within the housing between the inlet and the outlet, the obturator mounted on the shaft and movable relative to the shaft and relative to the housing in response to fluid flow between the inlet and the outlet; a sensing arm having a first end fixedly mounted on the shaft and a second end that engages the closure; a sensor system adapted to sense rotation of the shaft relative to the housing; and A flow sensor comprising: (Item 2) Item 10. The flow sensor of item 1, wherein the closure comprises a disk oriented transversely to the flow path. (Item 3) Item 3. The flow sensor of item 2, wherein the closure further comprises at least one lug extending between the disk and the shaft, the lug defining a hole for receiving the shaft. (Item 4) Item 4. The flow sensor of item 3, wherein the hole is sized to allow rotational and translational movement of the disk relative to the shaft. (Item 5) Item 3. The flow sensor of item 2, further comprising a seat surrounding the inlet, the closure being engageable with the seat. (Item 6) Item 6. The flow sensor of item 5, further comprising a spring acting between the closure and the housing to bias the closure into engagement with the seat. (Item 7) Item 10. The flow sensor of item 1, further comprising a protrusion extending from the sensor system into the housing, the spring acting between the protrusion and the sensing arm. (Item 8) Item 6. The flow sensor of item 5, further comprising a seal positioned between the seat and the closure and mounted on one of the seat or the closure. (Item 9) Item 10. The flow sensor of item 1, further comprising a weight mounted on the sensing arm distal to the shaft. (Item 10) Item 10. The flow sensor of item 1, further comprising a coupling portion extending between the sensing arm and the occlusion, the coupling portion positioned distal to the shaft for flexibly connecting the sensing arm to the occlusion. (Item 11) 2. The flow sensor of claim 1, further comprising an actuator for moving the sensing arm, the actuator comprising a push rod having a first end extending from the housing and a second end proximate the shaft and engageable with the sensing arm, the push rod defining an eccentric line of action relative to the shaft, thereby enabling a force applied to the push rod to rotate the sensing arm about the shaft. (Item 12) Item 12. The flow sensor of item 11, wherein the actuator further comprises a solenoid adapted to move the push rod. (Item 13) The sensor further includes an actuator for moving the sensing arm, the actuator comprising: a shaft having a first end protruding from the housing and a second end positioned within the housing proximate the shaft; a cam mounted on the second end of the shaft; Equipped with Item 1 , the flow sensor of item 1, wherein the cam is rotatable into and out of engagement with the sensing arm upon rotation of the shaft, thereby causing rotation of the sensing arm and the shaft. (Item 14) Item 14. The flow sensor of item 13, further comprising an electric motor engaged with the shaft and adapted to rotate the shaft to rotate the cam. (Item 15) Item 10. The flow sensor of item 1, wherein the actuator further comprises a lever arm attached to a first end of the shaft, the lever arm extending transversely to the shaft. (Item 16) Item 15. The flow sensor of item 14, further comprising a solenoid adapted to engage the lever arm and move the lever arm, thereby rotating the shaft. (Item 17) Item 10. The flow sensor of item 1, further comprising a magnet fixedly mounted on the shaft, the magnet positioned proximate to the sensor system. (Item 18) Item 18. The flow sensor of item 17, wherein the magnet is positioned within the housing. (Item 19) Item 19. The flow sensor of item 18, wherein the magnet is mounted on an end of the shaft. (Item 20) 20. The flow sensor of claim 19, wherein the magnet is surrounded by a non-magnetic sheath that protrudes from the housing. (Item 21) Item 10. The flow sensor of item 1, wherein the sensor system is positioned on the exterior of the housing. (Item 22) Item 1 , the flow sensor comprising a non-contact sensor. (Item 23) Item 10. The flow sensor of item 1, wherein the sensor system comprises a sensor selected from the group consisting of a magnetic sensor, a Hall effect sensor, and a capacitive sensor. (Item 24) Item 1 , the flow sensor comprising a magnetic position sensor. (Item 25) Item 23. The flow sensor of item 22, wherein the sensor system further comprises a controller in communication with the magnetic position sensor. (Item 26) 24. The flow sensor of claim 23, wherein the sensor system further comprises an adjustable delay circuit in communication with the controller, the adjustable delay circuit delaying communication of an alarm signal from the controller. (Item 27) A valve, the valve comprising: a housing having an inlet and an outlet; a seat surrounding the entrance; a shaft rotatably mounted within the housing; a valve closure member positioned within the housing and sealingly engageable with the seat, the valve closure member mounted on the shaft and movable relative to the shaft between an open position that allows flow from the inlet to the outlet and a closed position that prevents reverse flow; a sensing arm having a first end fixedly mounted on the shaft and a second end portion that engages the valve closure member; a spring operative to bias the sensing arm into contact with the valve closure member; a sensor system adapted to sense rotation of the shaft relative to the housing; and The valve is provided with: (Item 28) Item 28. The valve of item 27, wherein the spring acts between the housing and the sensing arm. (Item 29) Item 28. The valve of item 27, further comprising a protrusion extending from the sensor system into the housing, the spring acting between the protrusion and the sensing arm. (Item 30) Item 29. The valve of item 28, wherein the spring operates to bias the valve closure member to the closed position. (Item 31) Item 28. The valve of item 27, wherein the sensor system is mounted on the housing. (Item 32) The sensing arm a first projection extending from the second end portion; a second projection extending from the second end and in spaced relation to the first projection; Equipped with Item 28. The valve of item 27, wherein the first and second protrusions engage the valve closure member. (Item 33) Item 33. The valve of item 32, wherein the first and second protrusions are aligned along a line oriented parallel to the shaft. (Item 34) The valve closing member is a disc sealingly engageable with said seat; a first lug protruding from the disc, the first lug defining a first opening for receiving the shaft; a second lug protruding from said disc; and Equipped with 28. The valve of claim 27, wherein the second lug is disposed in a spaced relationship relative to the first lug and defines a second opening that receives the shaft, and the disc is rotatable about and relative to the shaft. (Item 35) Item 35. The valve of item 34, wherein the first and second openings include respective first and second slots oriented relative to the disc to permit translational movement of the disc toward and away from the seat. (Item 36) The sensing arm a first projection extending from the second end portion; a second projection positioned in spaced relation to the first projection and extending from the second end portion; and Equipped with Item 35. The valve of item 34, wherein the first and second protrusions engage the valve closure member. (Item 37) Item 37. The valve of item 36, wherein the first and second protrusions are aligned along a line oriented parallel to the shaft. (Item 38) Item 38. The valve of item 37, wherein the first protrusion engages the disc on one side of a diameter line of the disc and the second protrusion engages the disc on the opposite side of the diameter line, the diameter line being oriented perpendicular to the shaft. (Item 39) Item 37. The valve of item 36, wherein the second end portion of the sensing arm extends in a direction parallel to the shaft, and the first and second protrusions engage the disc at first and second points proximate a center of the disc. (Item 40) Item 40. The valve of item 39, wherein the first and second points are located beyond the center of the disc relative to the shaft. (Item 41) Item 28. The valve of item 27, further comprising a magnet fixedly mounted on the shaft, the magnet positioned proximate to the sensor system. (Item 42) Item 42. The valve of item 41, wherein the magnet is positioned within the housing. (Item 43) Item 43. The valve of item 42, wherein the magnet is mounted on the end of the shaft. (Item 44) Item 44. The valve of item 43, wherein the magnet is surrounded by a non-magnetic sheath protruding from the housing. (Item 45) Item 28. The valve of item 27, wherein the sensor system is positioned on the exterior of the housing. (Item 46) Item 28. The valve of item 27, wherein the sensor system comprises a non-contact sensor. (Item 47) Item 28. The valve of item 27, wherein the sensor system comprises a sensor selected from the group consisting of a magnetic sensor, a Hall effect sensor, and a capacitive sensor. (Item 48) Item 28. The valve of item 27, wherein the sensor system comprises a magnetic position sensor. (Item 49) Item 47. The valve of item 46, wherein the sensor system further comprises a controller in communication with the magnetic position sensor. (Item 50) Item 48. The valve of item 47, wherein the sensor system further comprises an adjustable delay circuit in communication with the controller, the adjustable delay circuit delaying communication of an alarm signal from the controller. (Item 51) 1. A method of detecting fluid flow through a valve, the valve comprising: a valve housing defining a seat; and a valve closure member positioned within the valve housing, the valve closure member sealingly engaged with the seat and movable between a closed position preventing fluid flow and an open position permitting fluid flow; The method includes using a sensing arm mounted on the housing; The sensing arm is engaged with the valve closure member to sense movement of the valve closure member between the closed and open positions. (Item 52) Item 52. The method of item 51, wherein sensing movement of the valve closure member includes sensing rotation of the sensing arm. (Item 53) Item 53. The method of item 52, wherein the rotation of the sensing arm senses rotational movement of the valve closure member. (Item 54) Item 53. The method of item 52, wherein the rotation of the sensing arm senses translational movement of the valve closure member. (Item 55) Item 53. The method of item 52, wherein the sensing arm is fixedly mounted on a shaft, the shaft being rotatably mounted on the housing, and sensing the rotation of the sensing arm includes sensing rotation of the shaft relative to the valve housing. (Item 56) further comprising calibrating the valve, wherein calibrating the valve comprises: causing a fluid to flow through the valve at a known rate; determining a position of the sensing arm while the fluid is flowing at the known rate; relating the position of the sensing arm to the known rate of fluid flow; Item 52. The method according to Item 51, comprising: (Item 57) further comprising calibrating the valve, wherein calibrating the valve comprises: flowing fluid through the valve at a first known rate; determining a first position of the sensing arm while the fluid is flowing at the first known rate; relating the first known rate of fluid flow to the first position of the sensing arm; flowing fluid through the valve at a second known rate different from the first known rate; determining a second position of the sensing arm while the fluid is flowing at the second known rate; associating the second known rate of fluid flow with the second position of the sensing arm; and Item 52. The method according to Item 51, comprising: (Item 58) Item 58. The method of item 57, wherein the first and second known rates of fluid flow range from 4 gallons (15 liters) per minute to 10 gallons (38 liters) per minute. (Item 59) 1. A fire suppression sprinkler system connectable to a water supply, the sprinkler system comprising: a standpipe connectable to the water supply; Multiple fire suppression sprinklers; a piping network providing fluid communication between the standpipe and the sprinkler; a check valve for controlling fluid flow between the standpipe and the piping network; Equipped with The check valve is a housing having an inlet connected to the standpipe and an outlet connected to the piping network; a seat surrounding the entrance; a shaft rotatably mounted within the housing; a valve closure member positioned within the housing, the valve closure member sealingly engageable with the seat, the valve closure member mounted on the shaft and movable relative to the shaft between an open position that allows flow from the inlet to the outlet and a closed position that prevents reverse flow; a sensing arm having a first end fixedly mounted on the shaft and a second end portion that engages the valve closure member; a spring operative to bias the sensing arm into contact with the valve closure member; a sensor system adapted to sense rotation of the shaft relative to the housing; and A sprinkler system comprising: (Item 60) 60. The system of claim 59, further comprising a shut-off valve positioned between the check valve and the standpipe for controlling fluid flow to the valve. (Item 61) Item 60. The system of item 59, further comprising a shut-off valve positioned within the housing between the inlet and the valve closure member. (Item 62) Item 60. The system of item 59, wherein the check valve is calibrated by relating a known rate of fluid flow to the rotational position of the shaft. (Item 63) Item 63. The system of item 62, wherein the check valve is calibrated to detect a fluid flow range of 4 gallons per minute (15 liters / minute) to 10 gallons per minute (38 liters / minute). (Item 64) Item 60. The system of item 59, further comprising a test drain valve in fluid communication with the check valve at a location between the valve closure member and the outlet. (Item 65) Item 60. The system of item 59, further comprising a pressure gauge in fluid communication with the check valve at a location between the valve closure member and the outlet. (Item 66) Item 60. The system of item 59, further comprising a pressure valve in fluid communication with the check valve at a location between the valve closure member and the outlet. (Item 67) Item 8. The flow sensor of item 7, wherein the protrusion extending from the sensor system into the housing has an eccentric cross-section. (Item 68) 30. The valve of claim 29, wherein the protrusion extending from the sensor system into the housing has an eccentric cross-section. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 is an isometric view of an exemplary flow sensor in accordance with the present invention.

[0030] [Figure 1A] FIG. 1A is a partial isometric cross-sectional view of the exemplary flow sensor shown in FIG.

[0031] [Figure 2] FIG. 2 is an elevational view of the components of the exemplary flow sensor of FIG. 1 on an enlarged scale.

[0032] [Figure 3] FIG. 3 is a partial isometric cross-sectional view of another exemplary embodiment of a flow sensor according to the present invention.

[0033] [Figure 4] 4 and 4A are elevational, partial cross-sectional views of another exemplary embodiment of a flow sensor according to the present invention. [Figure 4A] 4 and 4A are elevational, partial cross-sectional views of another exemplary embodiment of a flow sensor according to the present invention.

[0034] [Figure 5] FIG. 5 is a partial isometric cross-sectional view of another exemplary embodiment of a flow sensor according to the present invention.

[0035] [Figure 6] FIG. 6 is an isometric view of components used with an exemplary flow sensor according to the present invention.

[0036] [Figure 7] FIG. 7 is an elevational view of components used with an exemplary flow sensor according to the present invention.

[0037] [Figure 8]FIG. 8 is an isometric partial cutaway view of an exemplary control system for use with flow sensors and valves in accordance with the present invention.

[0038] [Figure 9] FIG. 9 is an isometric partial cutaway view of an exemplary valve according to the present invention.

[0039] [Figure 10] FIG. 10 is an isometric view of the components used in the valve shown in FIG.

[0040] [Figure 10A] FIG. 10A is an isometric view of components of an alternative embodiment used in the valve shown in FIG. 9 and the flow sensor shown in FIG.

[0041] [Figure 11] FIG. 11 is an isometric cutaway view of a portion of the valve shown in FIG.

[0042] [Figure 12] 12 and 13 are schematic diagrams of exemplary fire suppression sprinkler systems in accordance with the present invention. [Figure 13] 12 and 13 are schematic diagrams of exemplary fire suppression sprinkler systems in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0043] One aspect of the present invention relates to a flow sensor. As shown in FIG. 1, an exemplary embodiment of a flow sensor 10 according to the present invention includes a housing 12 having an inlet 14 and an outlet 16. As further shown in FIG. 1A, the housing 12 defines a fluid flow path 18 between the inlet and the outlet. A shaft 20 is rotatably mounted within the housing 12. An occlusion body 22 is positioned within the housing 12 between the inlet 14 and the outlet 16. The occlusion body 22 is mounted on the shaft 20 and is movable relative to the fluid flow and relative to the housing 12 in response to fluid flow between the inlet 14 and the outlet 16. In this exemplary embodiment, the occlusion body 22 includes a disk 24 oriented transversely to the flow path 18. As shown in FIG. 2, the occlusion body 22 further includes at least one lug 26 extending between the disk 24 and the shaft 20. The lug 26 defines a bore 28 that receives the shaft 20. In this exemplary embodiment, the hole 28 is sized and shaped to allow both rotational and translational movement of the disk 24 relative to the shaft 20. A seat 30 may be positioned within the housing 12 to support the closure 22. In this example, the seat 30 surrounds the inlet 14 and allows engagement between the closure 22 and the seat. As shown in FIG. 1A, a spring 32 acts between the closure 22 and the housing 12 to bias the closure into engagement with the seat 30. FIG. 2 shows an optional seal 34, which is positioned between the seat 30 and the closure 22 and may be mounted on either the seat 30 or the closure 22. In this exemplary embodiment, the seal 30 is mounted on the closure 22. A seal may be advantageous to further improve sensitivity to very small fluid flows by ensuring that the closure must be moved some amount to allow even small flows.

[0044] 1A, the flow sensor 10 further includes a sensing arm 36. The sensing arm 36 has a first end 38 fixedly mounted on the shaft 20 and a second end 40 that engages the closure 22. In this case, the term "fixedly mounted" means that the sensing arm 36 is attached to rotate with the shaft or is integrally formed with the shaft. The engagement between the first end 38 and the shaft 20 can therefore be via an interference fit, splined, welded, brazed, wedged, crimped, integrally cast and machined, or forged to ensure that the shaft 20 and arm 36 rotate together about the shaft longitudinal axis 41. The sensing arm 36 moves in response to occlusion movement and communicates that movement via the shaft 20 to a sensor system (described below), which generates a signal indicative of fluid flow rate through the housing. The occlusion movement is calibrated proportionally to the flow rate to detect fluid flow rate in units of volume per time, such as GPM. In this exemplary embodiment, a weight 42 is mounted on the sensing arm 36 distal to the shaft 20. In this example, the weight 42 is positioned at the second end 40 of the sensing arm 36 and serves to maintain engagement between the sensing arm and the occlusion disk. In another exemplary embodiment shown in FIG. 3 , a linkage 44 extends between the sensing arm 36 and the occlusion disk 22. The linkage 44 is positioned distal to the shaft 20 to flexibly connect the sensing arm 36 to the occlusion disk 22. In this example, the linkage includes a journal pin connection that allows rotation of the sensing arm 36 relative to the occlusion disk. Other types of connections also allow the sensing arm to rotate.

[0045] It would be advantageous to test the freedom of movement of the sensing arm 36 and the operation of the sensor system without disengaging or otherwise moving the occlusion 22. Further advantages may be gained if the sensing arm 36 can be moved manually or automatically by remote control via a control external to the housing 12. Such testing is enabled using an actuator 46. An exemplary manual actuator 46 is shown in FIG. 4 and includes a push rod 48 having a first end 50 extending from the housing 12 and a second end 52 engageable with the sensing arm 36 proximate the shaft 20. The push rod 48 defines a line of action 54 that is eccentric with respect to the shaft 20, thereby allowing a force applied to the push rod to rotate the sensing arm about the shaft. The push rod design of FIG. 4 is well suited to the automated actuator 46 shown in FIG. 4A, in which an electric solenoid 49 may be used to effect movement of the push rod 48. The solenoid 49 communicates with a microprocessor controller 70, described below, and may effect the testing and reporting functions of the actuator 46 in response to user commands. FIG. 5 illustrates another embodiment of the actuator 46; in this example, the actuator 46 comprises a shaft 56 having a first end 58 that protrudes from the housing 12 and a second end 60 that is positioned within the housing proximate the shaft 20. A cam 62 is mounted on the second end 60 of the shaft 56. The cam 62 is rotatable into and out of engagement with the sensing arm 36 upon rotation of the shaft 56, causing rotation of the sensing arm 36 and, consequently, of the shaft 20. An electric motor 51, controlled by a controller 70, may be directly coupled to the shaft 56 to effect the rotation. The actuator 46 may further comprise a lever arm 64 attached to the first end 58 of the shaft 56. A lever arm 64 extends transversely to the shaft 56 and provides leverage for easy manual rotation of the shaft or for remote actuation using a solenoid 49 controlled by a controller 70 .

[0046] The flow sensor 10 further includes a sensor system 66 adapted to sense rotation of the shaft 20 relative to the housing 12. As shown in FIGS. 1, 6, and 7, the sensor system 66 is mounted on the housing 12. The sensor system 66 advantageously includes a non-contact rotation sensor positioned on the exterior of the housing 12 and thus isolated from the working fluid therein. Such non-contact rotation sensors include magnetic, Hall-effect, or capacitive sensors and encoders. In this example, the sensor system 66 includes a magnetic position sensor 68, shown in FIG. 7, adapted to sense rotation of the shaft 20 relative to the housing 12. The position sensor 68 communicates with a microprocessor controller 70. In a practical exemplary design, the MLX90365 Gen III Triaxis® rotary and linear position sensor IC, commercially available from Melixis NV (Belgium), is feasible. The MLX90365 is described as a monolithic magnetic position processor integrated circuit that includes a Triaxis® Hall magnetic front end (position sensor 68), analog / digital signal conditioner, DSP for advanced signal processing, and output stage drivers.

[0047] As shown in FIG. 7 , the sensor system 66 of the valve 10 advantageously further includes a magnet 72 fixedly mounted on the shaft 20 at the end of the shaft. The magnet 72 is positioned within the housing 12, proximate the position sensor 68. The magnet 72 is surrounded by a non-magnetic sheath 74 that protrudes from the housing 12, the interior volume of the sheath experiencing the pressure of the working fluid within the housing 12. Forming the sheath 74 from a material that is substantially transparent to the magnetic field of the magnet 72 allows changes in the field to be sensed by the position sensor 64 as the sensing arm 36 moves the shaft 20. For high-pressure applications, brass, bronze, and stainless steel are expected to provide the strength necessary to withstand internal pressure while being magnetically transparent. Stainless steel is also corrosion-resistant and therefore advantageous for parts with tight clearances and relative movement. For low-pressure applications, a polymer sheath may be advantageous.

[0048] As shown in FIG. 8 , the sensor system 66 further includes an adjustable delay circuit 76 in communication with the controller 70, which delays communication of an alarm signal from the controller indicating movement of the occlusion 22. A sudden increase in fluid pressure may momentarily disturb the position of the occlusion, and such movement would be detected by the sensor system 66. The use of the delay circuit 76 allows programming of the valve sensor system 66 to avoid misinterpreting minor or momentary pressure surges as large fluid flows through the housing 12. A delay of up to 90 seconds can be programmed into the design, reducing or eliminating signaling of minor flow rates. In the exemplary embodiment shown in FIG. 8 , the delay circuit 76 is implemented via a rotary dip switch 78. The dip switch 78 is accessible from the outside of the sensor system 66 by removing a protective screw 80 from a through-hole in the sensor system cover 82, then inserting an instrument, such as a screwdriver, into the sensor system and rotating the dip switch 78. Markings 84 adjacent the through-holes assist in setting the desired delay.

[0049] Another aspect of the present invention relates to valves, such as wet or dry system valves, which may be used, for example, as check valves in fire suppression systems with integrated flow detection and sensing. FIG. 9 shows an exemplary embodiment of a valve 86 according to the present invention, which includes a housing 88 having an inlet 90 and an outlet 92. A seat 94 surrounds the inlet 90. A shaft 96 is rotatably mounted within the housing 88 between the inlet 90 and the outlet 92. In this example, the shaft 96 is rotatable on a pair of bearings 98, or for smaller sizes, on a single bearing 98, which may be integrally formed within the structure of the housing 88 or formed by a component pressed into (or otherwise attached to) the housing 88. A valve closure member 100 is positioned within the housing 88 and is sealingly engageable with the seat 94. A valve closure member 100 is mounted on the shaft 96 and is movable relative to the shaft 96 between an open position that allows flow from the inlet 90 to the outlet 92 and a closed position (as shown) in which the valve closure member sealingly engages the seat 94 to prevent flow. In this exemplary embodiment, the valve closure member includes a disk 102 that is sealingly engageable with the seat 94. As shown in FIGS. 10 and 11 , a first lug 104 projects from the disk 102. The first lug 104 defines a first opening 106 that receives the shaft 96. A second lug 108 also projects from the disk 102. The second lug 108 is disposed in a spaced-apart relationship with the first lug 104 and defines a second opening 110 that receives the shaft 96. The disk 102 is not rotationally fixed to the shaft 96 but is rotatable about and relative to the shaft. Advantageously, the first and second openings 106 and 110 are respective first and second oversized slots 112 and 114. The first and second slots 112 and 114 are oriented relative to the disk 102, in this example transverse to the plane of the disk, to allow translational movement of the disk toward and away from the seat 94 and rotational movement of the disk relative to the shaft 96.This relative translational and rotational movement allows the disk 102 to float relative to the seat 94, ensuring a good seal over a range of practical conditions. Other configurations of the slots 112 and 114 that allow for relative translational and rotational movement of the disk 102, such as oval or oversized holes, are also possible.

[0050] As shown in FIG. 10 , the valve 86 further includes a sensing arm 116 having a first end 118 fixedly mounted on the shaft 96. In this instance, the term “fixedly mounted” means that the sensing arm 116 is attached to or integrally formed with the shaft for rotation therewith. The engagement between the first end 118 and the shaft 96 may thus be via an interference fit, splined, welded, brazed, wedged, crimped, integrally cast and machined, or forged to ensure that the shaft 96 and arm 116 rotate together about the shaft longitudinal axis 120. A second end portion 122 of the sensing arm 116 engages the valve closure member 100, in this example, the disk 102. A spring 124 acts between the housing 88 (see also FIG. 9 ) and biases the valve closure member 100 into the closed position shown; it is advantageous if the spring 124 biases the valve closure member 100 into the closed position by acting against the sensing arm 116, thus keeping the sensing arm in intimate contact with the valve closure member 100 as shown in FIG. 10 . Forcing contact between the sensing arm 116 and the valve closure member 100 allows the sensing arm 116 to respond to movement of the valve closure member 100, whether translational, rotational, or a combination thereof, by rotation. Allowing the sensing arm 116 to respond to complex movements of the valve closure member increases the sensitivity of the flow sensor. However, other arrangements are possible, such as having the spring 124 acting directly on the valve closure member 100 and having an additional spring acting against the sensing arm 116 to bias the sensing arm 116 into contact with the valve closure member 100. Other methods of ensuring that the sensing arm 116 is maintained in or urged into contact with the valve closure member 100, such as the weighted arm 42 described in the embodiment of Figure 1A, are also feasible and within the scope of the present invention. An alternative embodiment is shown in Figure 10A in which a protrusion 67 extends from the sensor system 66 into the valve housing 88 (the cover plate 87 in this example is considered to be part of the sensor system). In this example, a spring 124 acts between the protrusion 67 and the sensor arm 116.It is expected that this configuration of spring 124 and protrusion 67 will eliminate variations in spring preload due to casting tolerances affecting the dimensions of the inner surface of housing 88. A smaller range of positional tolerances for protrusion 67 is expected to be achievable, which in turn should result in more repeatable positioning of the protrusion, smaller production variations in spring preload, and therefore improved consistency of valve response throughout production. Spring preload can be controlled even more precisely if protrusion 67 is eccentric or cam-like in cross-section, whereby rotation of protrusion 67 relative to sensor system 66 can specifically affect the preload on spring 124 by altering the location of engagement between protrusion 67 and spring 124. These exemplary embodiments can also be used to react springs for the flow sensors previously described.

[0051] It is advantageous if the second end portion 122 of the sensing arm 116 extends in a direction substantially parallel to the shaft 96. As shown in Figure 11, first and second protrusions 126 and 128 extend from the second end portion 122. The second protrusion 128 is disposed in a spaced-apart relationship with respect to the first protrusion 126 and engages the valve closure member 100 (disk 102). The first and second protrusions 126 and 128 are therefore aligned along a line 130 that is oriented substantially parallel to the shaft 96.

[0052] Because the sensing arm 116 is part of a sensor system used to detect and measure movement of the valve closure member 100, it is advantageous to position the sensing arm's second end portion 122 so that the sensing arm provides the greatest possible sensitivity. To achieve this goal, the second end portion 122 is positioned so that the first and second protrusions 126 and 128 engage the disc 102 at first and second points 132 and 134 on either side of a diametric line 136 oriented transversely to the shaft 96. This location of contact between the sensing arm 116 and the disc 102 further helps prevent the disc from wobbling about the line 136 and increases sensitivity to such wobble. Increased sensitivity is also achieved by positioning the sensing arm's second end portion 122 proximate to a center 138 of the disc 102. Advantages may be conferred when the first point 132 and the second point 134 are located beyond the center of the disk 102 relative to the shaft 96, as shown in Figure 10. In this context, the term "beyond the center" refers to a position beyond the center 138 as measured relative to an axis of rotation, such as the shaft axis 120.

[0053] As shown in FIG. 10 , a sensor system 66, as described above and shown in FIGS. 7 and 8 , is mounted on the housing 88 of a valve 86. Similar to the flow sensor 10 described above, it is advantageous to use a non-contact rotary sensor located on the exterior of the housing 88 and therefore isolated from the working fluid within the valve 86. Non-contact rotary sensors, including magnetic, Hall-effect, or capacitive sensors and encoders, are expected to provide practical valve designs. In this example, similar to the flow sensor 10, a magnetic position sensor 68, shown in FIG. 7 , is adapted to sense the rotation of a shaft 96 relative to the housing 88. The position sensor 68 communicates with a microprocessor controller 70. In a practical exemplary design, the MLX90365 Gen III Triaxis® rotary and linear position sensor IC, commercially available from Melixis NV (Belgium), is feasible.

[0054] 7, the sensor system 66 of the valve 10 again includes a magnet 72 fixedly mounted on the shaft 96, advantageously at the end of the shaft. The magnet 72 is located within the housing 12, but in proximity to the position sensor 68. The magnet 72 is surrounded by a non-magnetic sheath 74 that protrudes from the housing 12, the interior volume of which experiences the pressure of the working fluid within the housing 12.

[0055] It is anticipated that the valve 86 may be employed in a method for detecting and measuring fluid flow between the inlet 90 and outlet 92. An exemplary method for detecting fluid flow through the valve 86 according to the present invention includes using a sensing arm 116 to detect movement of the valve closure member 100. Because the sensing arm 116 is mounted on the housing 88 and engaged with the valve closure member 100, its movement serves as a surrogate indicator for the movement of the valve closure member 100 between a closed position (sealingly engaged with the valve seat 94 indicating an absence of flow) and an open position disengaged from the valve seat, and the position can be directly related to flow through the valve.

[0056] Thus, sensing movement of the valve closure member 100 includes sensing movement of the sensing arm 116. As described above, the sensing arm 116 is fixedly mounted on the shaft 96, which is rotatably mounted on the housing 88. Because the sensing arm is engaged with the valve closure member 100, the sensing arm rotates in response to both translational and rotational movement of the valve closure member as it disengages from the seat 94 in response to fluid flow through the valve 86. Thus, sensing fluid flow through the valve 86 is accomplished in this example by sensing movement of the sensing arm 116, which includes sensing rotation of the shaft 96 relative to the valve housing 88 using the sensor system 66. It is expected that sensing the rotation of the shaft 96 provides a reliable and repeatable indication of fluid flow through the valve 86.

[0057] The exemplary method of detecting fluid flow through valve 86 can serve as a basis for measuring fluid flow rate by calibrating the valve. By way of example, a further step added to the above detection method for calibrating the valve is: causing fluid to flow through valve 86 at a known rate; determining the position of the sensing arm 116 while the fluid is flowing at a known rate; Correlating the position of the sensing arm 116 with a known fluid flow rate; may include:

[0058] It may be advantageous to calibrate the valve over a range of flow rates. Exemplary method steps for this calibration include: causing fluid to flow through the valve 86 at a first known rate; determining a first position of the sensing arm 116 while the fluid is flowing at a first known rate; Associating a first known rate of fluid flow with a first position of the sensing arm 116; causing the fluid to flow through the valve 86 at a second known rate different from the first known rate; determining a second position of the sensing arm 116 while the fluid is flowing at a second known rate; associating a second known rate of fluid flow with a second position of the sensing arm 116; Includes.

[0059] These calibration steps may, of course, be repeated for three or more known flow rates in a practical design. An exemplary range of flow rates of interest may be a fluid flow of approximately 4 gallons (15 liters) per minute to approximately 10 gallons (38 liters) per minute, although other ranges are, of course, feasible. As described above, determining various positions of the sensing arm 116 during fluid flow through the valve 86 may be accomplished using the sensor system 66 to determine the rotational position of the shaft 96. The various positions of the sensing arm 116 may be related to corresponding known flow rates using, for example, a look-up table stored in the memory of the microprocessor controller 70 of the sensor system 66. Alternatively, a functional relationship between sensing arm position and flow rate may be derived, and the function may be stored in the controller 70. The controller 70 may use the sensing arm position and the table or function to calculate and display the flow rate. The flow volume may then be calculated by the controller by integrating the flow rate over time. A dial indicator with a dial calibrated according to flow rate may also be used to indicate the position of the sensing arm. If an eccentric or cam-like protrusion 67 is employed, calibration may additionally include rotation of the protrusion 67 to adjust the preload on the spring 124. Such adjustment may be made, for example, to improve the consistency or accuracy of the calibration.

[0060] As shown in FIG. 8, the sensor system 66 further includes adjustable delay circuitry 76 in communication with the controller 66, which delays communication of an alarm signal from the controller indicating the opening of the valve 10. A sudden increase in water pressure may momentarily disturb the position of the valve closure member 100 (see FIG. 9), and such movement will be detected by the sensing system 66. The use of the delay circuitry 76 allows programming of the sensing system 66 to avoid, for example, misinterpreting a minor water pressure surge as the opening of the valve 86 in response to a fire. A delay of up to 90 seconds may be programmed into a practical design to reduce or eliminate false fire alarm signaling by the valve 86.

[0061] As shown in Figures 12 and 13, the exemplary valve 86 may be used as a check valve in a fire suppression sprinkler system 140. The exemplary system 140 may be deployed in structures such as warehouses, office buildings, and hotels, to name a few. As shown in Figure 12, the system 140 includes a standpipe 142 connectable to a water supply 144, such as a municipal water supply for the structure. A plurality of fire suppression sprinklers 146 are distributed throughout the structure. A piping network 148 extends throughout the structure and provides fluid communication between the standpipe 142 and the sprinklers 146. The piping network 148 may contain water, as in a wet system, or may be initially filled with air or an inert gas, as in a dry system.

[0062] The check valve 86 controls fluid flow between the standpipe 142 and the piping network 148. As shown in FIG. 9 , the exemplary check valve 86 includes a housing 88 having an inlet 90 connected to the standpipe 142 and an outlet 92 connected to the piping network 148. A seat 94 surrounds the inlet 90. A shaft 96 is rotatably mounted within the housing 88. A valve closure member 100 is positioned within the housing 88 and sealingly engages the seat 94. The valve closure member is mounted on the shaft 96 and is movable relative to the shaft 96 between an open position that allows flow from the inlet 90 to the outlet 92 and a closed position that prevents reverse flow. As shown in FIG. 10 , a sensing arm 116 has a first end 118 fixedly mounted on the shaft 96 and a second end portion 122 that engages the valve closure member 100. A spring 124 operates to bias the sensing arm 116 into contact with the valve closure member 100. The sensor system 66 is adapted to sense rotation of the shaft 96 relative to the housing 88. Further details of the check valve 86 and the sensor system 66 are described above and will not be repeated here.

[0063] As shown in FIG. 12 , when the check valve 86 is used in a fire suppression system 140, the system may further include a shut-off valve 150 positioned between the check valve 86 and the standpipe 142. The shut-off valve 150 controls fluid flow from the supply 144 to the valve 86 and, therefore, the piping network 148, and may therefore be used to isolate the network for performing testing and draining functions. In the exemplary system embodiment 140 shown in FIG. 12 , the shut-off valve 150 is a separate, discrete valve that, in this example, is coupled to the standpipe 142 and the housing 88 using a mechanical linkage 152. The shut-off valve 150 in this example includes a handwheel 154 for manually opening and closing the valve and a valve status indicator 156. In an alternative embodiment shown in FIG. 13 , the shut-off valve 150 is positioned within the housing 88 of the check valve 86 between the inlet 90 and the valve closure member 100 (not visible).

[0064] 12 and 13, system 140 may further include a test drain valve 158 in fluid communication with check valve 86 at a location between valve closure member 100 (not visible) and check valve outlet 92. Additional equipment, such as a system pressure gauge 160 and a pressure valve 162, may also be in fluid communication with check valve 86 at a location between the valve closure member and the outlet. In this exemplary embodiment, a port 164 is provided in housing 88 for tethering the system for fluid communication between the system and the additional equipment. Note that pressure valve 162 is mounted on and in fluid communication with test drain valve 158.

[0065] When used with fire suppression system 140, check valve 86 can detect and measure fluid flow into the system. To perform this detection and measurement function, check valve 86 is calibrated by relating known rates of fluid flow to rotational positions of the shaft, as described above. In a practical exemplary system, the flow rate range of interest over which the check valve can be calibrated to detect fluid flow ranges from 4 gallons per minute (15 liters / minute) to 10 gallons per minute (38 liters / minute).

[0066] It is expected that the exemplary flow sensors as described and claimed will provide superior sensitivity and accuracy over prior art sensors. Valves such as the examples disclosed herein are expected to improve practical fire suppression system design because they avoid the need for a separate flow switch and its attendant drawbacks, such as loss of pressure head, or the need for an intermediate chamber and separate pressure switch in dry systems. Further improvements to the robustness of both the sensor and the valve are also expected through the elimination of paddle switches, which are subject to physical damage due to their lightweight construction required to detect low flow rates in large diameter pipes. System repair and maintenance can also be improved by isolating the sensor system from the working fluid within the valve or sensor housing, as there would be no need to drain the entire piping network to effect repair or replacement of the sensor system. Due to the sensitivity and accuracy of the sensor, the valve can also be used to measure flow rate and distinguish between leaks and flame conditions in the system. The size of a flame can also be determined by flow rate measurements.

[0067] All embodiments of the claimed invention described herein are expressly provided by way of example only. Numerous variations and modifications may be made to the exemplary embodiments described herein without departing from the concepts of the disclosure. Additionally, the scope of the disclosure is intended to encompass all modifications and combinations of all elements, features, and aspects described in the specification and claims and shown in the drawings. All such modifications and combinations are intended to be within the scope of the disclosure.

Claims

1. A flow sensor, the flow sensor comprising: a housing having an inlet and an outlet, the housing defining a flow path between the inlet and the outlet; a shaft rotatably mounted within the housing; an obstruction positioned within the housing between the inlet and the outlet, the obstruction mounted on the shaft and movable relative to and independent of the shaft and relative to the housing in response to fluid flow between the inlet and the outlet; a sensing arm having a first end fixedly mounted on the shaft and a second end that engages the closure; a sensor system adapted to sense rotation of the shaft relative to the housing; and A flow sensor comprising:

2. The flow sensor of claim 1 , wherein the occlusion comprises a disk oriented transversely to the flow path.

3. The flow sensor of claim 2 , wherein the closure further comprises at least one lug extending between the disk and the shaft, the lug defining a hole for receiving the shaft.

4. The flow sensor of claim 3 , wherein the hole is sized to allow rotational and translational movement of the disk relative to the shaft.

5. The flow sensor of claim 2 further comprising a seat surrounding the inlet, the closure being engageable with the seat.

6. The flow sensor of claim 5 further comprising a spring acting between the closure and the housing for biasing the closure into engagement with the seat.

7. The flow sensor of claim 1 , further comprising a protrusion extending from the sensor system into the housing, the spring acting between the protrusion and the sensing arm.

8. The flow sensor of claim 5 , further comprising a seal positioned between the seat and the closure and mounted on one of the seat or the closure.

9. The flow sensor of claim 1 further comprising a weight mounted on the sensing arm distal to the shaft.

10. 10. The flow sensor of claim 1, further comprising a coupling extending between the sensing arm and the occlusion, the coupling positioned distally of the shaft for flexibly connecting the sensing arm to the occlusion.

11. 2. The flow sensor of claim 1, further comprising an actuator for moving the sensing arm, the actuator comprising a push rod having a first end extending from the housing and a second end proximate the shaft and engageable with the sensing arm, the push rod defining an eccentric line of action relative to the shaft, thereby enabling a force applied to the push rod to rotate the sensing arm about the shaft.

12. The flow sensor of claim 11 , wherein the actuator further comprises a solenoid adapted to move the push rod.

13. The sensor further includes an actuator for moving the sensing arm, the actuator comprising: a shaft having a first end protruding from the housing and a second end positioned within the housing proximate the shaft; a cam mounted on the second end of the shaft; Equipped with 2. The flow sensor of claim 1, wherein the cam is rotatable into and out of engagement with the sensing arm upon rotation of the shaft, thereby causing rotation of the sensing arm and the shaft.

14. The flow sensor of claim 13 , further comprising an electric motor engaged with the shaft and adapted to rotate the shaft to rotate the cam.

15. The flow sensor of claim 13 , wherein the actuator further comprises a lever arm attached to a first end of the shaft, the lever arm extending transversely to the shaft.

16. 16. The flow sensor of claim 15, further comprising a solenoid adapted to engage and move the lever arm, thereby rotating the shaft.

17. The flow sensor of claim 1 , further comprising a magnet fixedly mounted on the shaft, the magnet positioned proximate to the sensor system.

18. The flow sensor of claim 17 , wherein the magnet is positioned within the housing.

19. 20. The flow sensor of claim 18, wherein the magnet is mounted on an end of the shaft.

20. 20. The flow sensor of claim 19, wherein the magnet is surrounded by a non-magnetic sheath that protrudes from the housing.

21. The flow sensor of claim 1 , wherein the sensor system is located on an exterior of the housing.

22. The flow sensor of claim 1 , wherein the sensor system comprises a non-contact sensor.

23. The flow sensor of claim 1 , wherein the sensor system comprises a sensor selected from the group consisting of a magnetic sensor, a Hall effect sensor, and a capacitive sensor.

24. The flow sensor of claim 1 , wherein the sensor system comprises a magnetic position sensor.

25. 25. The flow sensor of claim 24, wherein the sensor system further comprises a controller in communication with the magnetic position sensor.

26. 26. The flow sensor of claim 25, wherein the sensor system further comprises an adjustable delay circuit in communication with the controller, the adjustable delay circuit delaying communication of an alarm signal from the controller.

27. A valve, the valve comprising: a housing having an inlet and an outlet; a seat surrounding the entrance; a shaft rotatably mounted within the housing; a valve closure member positioned within the housing and sealingly engageable with the seat, the valve closure member mounted on the shaft and movable relative to and independently of the shaft between an open position that allows flow from the inlet to the outlet and a closed position that prevents reverse flow; a sensing arm having a first end fixedly mounted on the shaft and a second end portion that engages the valve closure member; a spring operative to bias the sensing arm into contact with the valve closure member; a sensor system adapted to sense rotation of the shaft relative to the housing; and The valve is provided with:

28. 28. The valve of claim 27, wherein the spring acts between the housing and the sensing arm.

29. 28. The valve of claim 27, further comprising a protrusion extending from the sensor system into the housing, the spring acting between the protrusion and the sensing arm.

30. 29. The valve of claim 28, wherein the spring operates to bias the valve closure member to the closed position.

31. 28. The valve of claim 27, wherein the sensor system is mounted on the housing.

32. The sensing arm a first projection extending from the second end portion; a second projection extending from the second end and in spaced relation to the first projection; Equipped with 28. The valve of claim 27, wherein the first and second protrusions engage the valve closure member.

33. 33. The valve of claim 32, wherein the first and second protrusions are aligned along a line oriented parallel to the shaft.

34. The valve closing member is a disc sealingly engageable with said seat; a first lug protruding from the disc, the first lug defining a first opening for receiving the shaft; a second lug protruding from said disc; and Equipped with 28. The valve of claim 27, wherein the second lug is disposed in a spaced relationship relative to the first lug and defines a second opening that receives the shaft, and the disc is rotatable about and relative to the shaft.

35. 35. The valve of claim 34, wherein the first and second openings include respective first and second slots oriented relative to the disc to permit translational movement of the disc toward and away from the seat.

36. The sensing arm a first projection extending from the second end portion; a second projection positioned in spaced relation to the first projection and extending from the second end portion; and Equipped with 35. The valve of claim 34, wherein the first and second projections engage the valve closure member.

37. 37. The valve of claim 36, wherein the first and second protrusions are aligned along a line oriented parallel to the shaft.

38. 38. The valve of claim 37, wherein the first protrusion engages the disc on one side of a diameter line of the disc and the second protrusion engages the disc on an opposite side of the diameter line, the diameter line being oriented perpendicular to the shaft.

39. 37. The valve of claim 36, wherein the second end portion of the sensing arm extends in a direction parallel to the shaft, and the first and second protrusions engage the disc at first and second points proximate a center of the disc.

40. 40. The valve of claim 39, wherein the first and second points are located beyond the center of the disc relative to the shaft.

41. 28. The valve of claim 27, further comprising a magnet fixedly mounted on the shaft, the magnet positioned proximate to the sensor system.

42. 42. The valve of claim 41, wherein the magnet is positioned within the housing.

43. 43. The valve of claim 42, wherein the magnet is mounted on an end of the shaft.

44. 44. The valve of claim 43, wherein the magnet is surrounded by a non-magnetic sheath projecting from the housing.

45. 28. The valve of claim 27, wherein the sensor system is located on an exterior of the housing.

46. 30. The valve of claim 27, wherein the sensor system comprises a non-contact sensor.

47. 28. The valve of claim 27, wherein the sensor system comprises a sensor selected from the group consisting of a magnetic sensor, a Hall effect sensor, and a capacitive sensor.

48. 28. The valve of claim 27, wherein the sensor system comprises a magnetic position sensor.

49. 49. The valve of claim 48, wherein the sensor system further comprises a controller in communication with the magnetic position sensor.

50. 50. The valve of claim 49, wherein the sensor system further comprises an adjustable delay circuit in communication with the controller, the adjustable delay circuit delaying communication of an alarm signal from the controller.

51. 1. A method of detecting fluid flow through a valve, the valve comprising: a valve housing defining a seat; a valve closure member positioned within the valve housing, the valve closure member mounted on a shaft rotatably mounted within the housing, the valve closure member sealingly engaged with the seat and movable between a closed position preventing the fluid flow and an open position allowing the fluid flow, the valve closure member mounted on the shaft and movable relative to and independent of the shaft, the shaft being rotatably mounted within the valve housing; a sensing arm mounted on the shaft, the sensing arm being movable independently of the valve closing member, the sensing arm being engaged with the valve closing member; Equipped with The method comprises: Sensing movement of the valve closure member between the closed and open positions with the sensing arm. A method comprising:

52. 52. The method of claim 51, wherein sensing movement of the valve closure member comprises sensing rotation of the sensing arm.

53. 53. The method of claim 52, wherein the rotation of the sensing arm senses rotational movement of the valve closure member.

54. 53. The method of claim 52, wherein the rotation of the sensing arm senses translational movement of the valve closure member.

55. 53. The method of claim 52, wherein sensing the rotation of the sensing arm comprises sensing rotation of the shaft relative to the valve housing.

56. further comprising calibrating the valve, wherein calibrating the valve comprises: causing a fluid to flow through the valve at a known rate; determining a position of the sensing arm while the fluid is flowing at the known rate; relating the position of the sensing arm to the known rate of fluid flow; 52. The method of claim 51, comprising:

57. further comprising calibrating the valve, wherein calibrating the valve comprises: causing fluid to flow through the valve at a first known rate; determining a first position of the sensing arm while the fluid is flowing at the first known rate; Associating the first known rate of fluid flow with the first position of the sensing arm; causing fluid to flow through the valve at a second known rate different from the first known rate; determining a second position of the sensing arm while the fluid is flowing at the second known rate; associating the second known rate of fluid flow with the second position of the sensing arm; and 52. The method of claim 51, comprising:

58. 58. The method of claim 57, wherein the first and second known rates of fluid flow range from 4 gallons per minute (15 liters) to 10 gallons per minute (38 liters).

59. 1. A fire suppression sprinkler system connectable to a water supply, the sprinkler system comprising: a standpipe connectable to the water supply; Multiple fire suppression sprinklers; a piping network providing fluid communication between the standpipe and the sprinkler; a check valve for controlling fluid flow between the standpipe and the piping network; Equipped with The check valve is a housing having an inlet connected to the standpipe and an outlet connected to the piping network; a seat surrounding the entrance; a shaft rotatably mounted within the housing; a valve closure member positioned within the housing, the valve closure member sealingly engageable with the seat, the valve closure member mounted on the shaft and movable relative to and independently of the shaft between an open position that allows flow from the inlet to the outlet and a closed position that prevents reverse flow; a sensing arm having a first end fixedly mounted on the shaft and a second end portion that engages the valve closure member; a spring operative to bias the sensing arm into contact with the valve closure member; a sensor system adapted to sense rotation of the shaft relative to the housing; and A sprinkler system comprising:

60. 60. The system of claim 59, further comprising a shut-off valve positioned between the check valve and the standpipe for controlling fluid flow to the valve.

61. 60. The system of claim 59, further comprising a shut-off valve positioned within the housing between the inlet and the valve closure member.

62. 60. The system of claim 59, wherein the check valve is calibrated by relating a known rate of fluid flow to a rotational position of the shaft.

63. 63. The system of claim 62, wherein the check valve is calibrated to detect a fluid flow range of 4 gallons per minute (15 liters / minute) to 10 gallons per minute (38 liters / minute).

64. 60. The system of claim 59, further comprising a test drain valve in fluid communication with the check valve at a location between the valve closure member and the outlet.

65. 60. The system of claim 59, further comprising a pressure gauge in fluid communication with the check valve at a location between the valve closure member and the outlet.

66. 60. The system of claim 59, further comprising a pressure valve in fluid communication with the check valve at a location between the valve closure member and the outlet.

67. The flow sensor of claim 7 , wherein the protrusion extending from the sensor system into the housing has an eccentric cross section perpendicular to the direction in which the protrusion extends from the sensor system into the housing.

68. 30. The valve of claim 29, wherein the protrusion extending from the sensor system into the housing has an off-center cross section perpendicular to the direction in which the protrusion extends from the sensor system into the housing.

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