Calibrated flow rate sensing and flow control device
A fluid flow rate sensor, which may also be the basis of a valve for a fire suppression system, uses a sensing arm to convey motion of an obturation body or a valve closing member to a sensor system which evaluates the motion and generates a calibrated measure of the flow rate and/or an alarm signal in response if warranted. The obturation body and the valve closing member are capable of both rotation and translational motion, both of which are sensed using the sensing arm. The sensor system is isolated from the fluid within the valve.
1 . A valve, said valve comprising:
a housing having an inlet and an outlet;
a seat surrounding said inlet;
a shaft rotatably mounted within said housing;
a valve closing member positioned within said housing and sealingly engageable with said seat, said valve closing member mounted on said shaft and movable relatively to and independently of said shaft between an open position allowing flow from said inlet to said outlet, and a closed position preventing reversal of said flow;
a sensing arm having a first end fixedly mounted on said shaft and a second end portion engaging said valve closing member; and
a spring acting to bias said sensing arm into contact with said valve closing member;
a sensor system adapted to sense rotation of said shaft relatively to said housing.
2 . The valve according to claim 1 , wherein said spring acts between said housing and said sensing arm.
3 . The valve according to claim 1 , further comprising a projection extending from said sensor system into said housing, said spring acting between said projection and said sensing arm.
4 . The valve according to claim 3 , wherein said projection extending from said sensor system into said housing has an eccentric cross section.
5 . The valve according to claim 2 , wherein said spring acts to bias said valve closing member into said closed position.
6 . The valve according to claim 1 , wherein said sensor system is mounted on said housing.
7 . The valve according to claim 1 , wherein said sensing arm comprises:
a first projection extending from said second end portion;
a second projection extending from said second end and in spaced relation to said first projection, said first and second projections engaging said valve closing member.
8 . The valve according to claim 7 , wherein said first and second projections are aligned along a line oriented parallel to said shaft.
9 . The valve according to claim 1 , wherein said valve closing member comprises:
a disk sealingly engageable with said seat;
a first lug projecting from said disk, said first lug defining a first opening receiving said shaft;
a second lug projecting from said disk, said second lug being arranged in spaced relation to said first lug and defining a second opening receiving said shaft, said disk being rotatable about said shaft relatively thereto.
10 . The valve according to claim 9 , wherein said first and second openings comprise respective first and second slots, said first and second slots being oriented relatively to said disk so as to permit translational motion of said disk toward and away from said seat.
11 . The valve according to claim 9 , wherein said sensing arm comprises:
a first projection extending from said second end portion;
a second projection extending from said second end portion positioned in spaced relation to said first projection, said first and second projections engaging said valve closing member.
12 . The valve according to claim 11 , wherein said first and second projections are aligned along a line oriented parallel to said shaft.
13 . The valve according to claim 12 , wherein said first projection engages said disk on one side of a diametral line of said disk and said second projection engages said disk on an opposite side of said diametral line, said diametral line being oriented perpendicularly to said shaft.
14 . The valve according to claim 11 , wherein said second end portion of said sensing arm extends in a direction parallel to said shaft and said first and second projections engage said disk at first and second points proximate to a center of said disk.
15 . The valve according to claim 14 , wherein said first and second points are located over center of said disk relatively to said shaft.
16 . The valve according to claim 1 , further comprising a magnet fixedly mounted on said shaft, said magnet being positioned proximate to said sensor system.
17 . The valve according to claim 16 , wherein said magnet is positioned within said housing.
18 . The valve according to claim 17 , wherein said magnet is mounted on an end of said shaft.
19 . The valve according to claim 18 , wherein said magnet is surrounded by a non-magnetic sheath projecting from said housing.
20 . The valve according to claim 1 , wherein said sensor system is positioned on an exterior of said housing.
21 . The valve according to claim 1 , wherein said sensor system comprises a non-contact sensor.
22 . The valve according to claim 1 , wherein said sensor system comprises a sensor selected from the group consisting of magnetic sensors, Hall effect sensors and capacitive sensors.
23 . The valve according to claim 1 , wherein said sensor system comprises a magnetic position sensor.
24 . The valve according to claim 23 , wherein said sensor system further comprises a controller in communication with said magnetic position sensor.
25 . The valve according to claim 22 , wherein said sensor system further comprises an adjustable delay circuit in communication with said controller for delaying communication of an alarm signal from said controller.
26 . A fire suppression sprinkler system connectable to a water supply, said sprinkler system comprising:
a standpipe connectable to said water supply;
a plurality of fire suppression sprinklers;
a piping network providing fluid communication between said standpipe and said sprinklers;
a check valve controlling fluid flow between said standpipe and said piping network, said check valve comprising:
a housing having an inlet connected to said standpipe and an outlet connected to said piping network;
a seat surrounding said inlet;
a shaft rotatably mounted within said housing;
a valve closing member positioned within said housing and sealingly engageable with said seat, said valve closing member mounted on said shaft and movable relatively to and independently of said shaft between an open position allowing flow from said inlet to said outlet, and a closed position preventing reversal of said flow;
a sensing arm having a first end fixedly mounted on said shaft and a second end portion engaging said valve closing member;
a spring acting to bias said sensing arm into contact with said valve closing member;
a sensor system adapted to sense rotation of said shaft relatively to said housing.
27 . The system according to claim 26 , further comprising a shutoff valve positioned between said check valve and said standpipe for controlling fluid flow to said valve.
28 . The system according to claim 26 , further comprising a shutoff valve positioned within said housing between said inlet and said valve closing member.
29 . The system according to claim 26 , wherein said check valve is calibrated by correlating a known rate of fluid flow with a rotational position of said shaft.
30 . The system according to claim 29 , wherein said check valve is calibrated to detect a fluid flow range from 4 gallons per minute (15 liters/minute) to 10 gallons per minute (38 liters/minute).
31 . The system according to claim 26 , further comprising a test and drain valve in fluid communication with said check valve at a position between said valve closing member and said outlet.
32 . The system according to claim 26 , further comprising a pressure gage in fluid communication with said check valve at a position between said valve closing member and said outlet.
33 . The system according to claim 26 , further comprising a pressure valve in fluid communication with said check valve at a position between said valve closing member and said outlet.