CA1294345C - Electronic controlled gas valve and method - Google Patents

Abstract

ELECTRONIC CONTROLLED GAS VALVE AND METHOD

ABSTRACT OF THE DISCLOSURE

An electronic controlled gas valve and method are provided for regulating a gas flow rate to maintain a desired gas flow rate under varying operating conditions. A single valve disc opens and closes both the main gas supply seat and the regulator gas supply seat in response to signals provided by a programmable microprocessor control. A manual on-off valve is provided for manually terminating the flow of gas through the gas valve, and includes a meltable manual switch that melts at a predetermined temperature to allow the manual valve to close.

Description

~ 3-~5 ELECTRONIC CONTROLLED GAS VALVE AND METHOD

Back~round of the Invention This invention pertains to gas-fired furnaces, and ~ore particularly to an electronic controlled gas valve and method for regulating the flow of a fuel to a gas-fired furnace.

Typically, a gas-fired furnace comprises a com~ustion chamber having disposed therein burner devices for burning a mixture of combustion air and fuel, a heat exchan~er for receiving the combusted fuel air mixture, a fan or blower ~or drawing combustion air into the combustion chamber and for drawing the combusted fuel air mixture through the heat exchanger, and a gas supply valve for supplying the fuel to the burner devices.

Generally, most gas supply valves are of a somewhat complex structure in that they involve multiple electromechanical interaction between selected elements or parts for supplying a flow of fuel. For example, most prior art gas cUpply valves have two separate valve members to control gas flow to the burners. One of these members ls a maln seat that is individually controlled to be either fully open or fully closed. The other member is a diaphragm-spring mechanlsm that is individually controlled to vary the gas flow through the gas valve outlet.

Summary of the Invention It is an object of the present invention to provide an improved gas supply valve and me~hod of control thereor.

Another object of the present invention is to provide an improved gas supply valve that utilize8 one valve member to operate both the main gas seat and the regulating gas seat.

2 12~43~5 Yet another obj ect of the present inv~ntion i~ to provide an improved gas supply valve that i~ controlled by a programmable microprocessor control.

Further objects of the present invention will appear as the description proceeds.

In one form of the present invention there is provided a fluid flow control device comprising a housing having an inlet and an outlet, and a regulator chamber in the housing and having a regulator opening and a main opening. The regulator chamber is fluidly communlcable with the housing inlet and outlet through the regulator opening and main opening, respectively. A regulator disc member is disposed in the regulator chamber and is selectively positionable to any one of a plurality of positions between a first position wherein the regulator disc member closes the main opening and a second position wherein the regulator disc member closes the regulator opening for controlling the flow rate of a fluid through the housing between a zero flow rate and a maximum flow rate.

In another form of the present invention, there i~ a method of controlling the flow rate of a fluid through a housing having an lnlet and an outlet comprising the steps of providing a regulator chamber in the housing and having a regulator opening and a main opening. A regulator disc member is provided in the regulator chamber and is selectively movable between a first position closlng the main opening and a second position closing the regulator opening.
A flow of fluid is provided to the regulator opening and the fluid pressure created thereby is sensed. Depending upon the pressure created by the fluid flow, the regulator disc member is positioned at a selected point to provide a desired flow 35 rate.

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Further steps of this method may comprise moving the regulator disc member to the first position, terminating the supply of fluid flow, continuing to sense fluid pressure in the regulator chamber caused by undesired fluid flow, and, upon sensing an undesired flow of fluid, manually shutting off the housing inlet.

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Brief Description of the Drawin~s The above-mentioned and other feature~ and ~bjects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be bettèr understood by reference to the following description of an embodiment of the in~ention taken in conjunction with the accompanying drawings, wherein:

Figure 1 is a partially broken-away side elevational view of a furn&ce incorporating the principles of the present invention;

Figure 2 includes a sectional view of a gas regulator device in conjunction with a schematic of a furnace control system incorporating the principles of the present invention;

Figure 3 is a plot of a curve indicating the relationship between heat exchanger pressure differential and optimum ~anifold gas pressure; and Figure 4 is a block diagram of a portion of the furnace control system.

Detailed Descript~on Referring to Figure 1, there i8 illustrated a gas-fired furnace which may be operatet according to the principles of the present i~vention. The following description is made with re~erence to condensing furnace 10, but it should be underætood that the present invention contemplates 3Q incorporation with a noncondensing-type furnace. Referring now to Figure 1, condensing furnace 10 includes in major part steel cabinet 12 housing therein burner assembly 14, gas regulator 16, heat exchanger assembly 18, inducer housing 20 supporting inducer motor 22 and inducer wheel 24, and circulating air blower 26. Gas regulator 16 includes pilot circuitry for controlling and proving the pilot flame. This 12~43~5 pilot c~rcuitry or control can be a BDP model 740A pilot obtainable from BDP Company, Indianapolis, ~ndiana.

Burner assembly 14 includes at least one inshot burner 28 for at least one primary heat exchanger 30. surner 28 receives a flow of combustible gas from gas regulator 16 and injects the gas into primary heat exchanger 30. A part of the injection process includes drawing air into heat exchanger assembly 18 so that the gas and air mixture may be combusted therein. A
flow of combustion air is delivered through combustion air inlet 32 to be mixed with the gas delivered to burner assembly 14.

Primary heat exchanger 30 includes an outlet 34 opening into chamber 36. Connected to chamber 36 and in fluid communication therewith is at least one condensing heat exchanger 38 having an inlet 40 and an outlet 42. Outlet 42 opens into chamber 44 for venting exhaust flue gases and condensate.
Inducer housing 20 is connected to chamber 44 and has mo~mted therewith inducer motor 22 with inducer wheel 24 for drawing the combusted gas air mixture from burner as~embly 14 through heat exchanger assembly 18. Air blower 26 delivers air to be heated upwardly through air pas9age 52 and over heat exchanger assembly 18, and the cool air passing over conden~ing he~t exchanger 38 lowers the heat exchanger wall temperature below the dew point of the combusted gas air mixture causing a portion of the water vapor in the combusted gas air mixture to condense, thereby recovering a portion of the sensible and latent heat energy. The condensate formed within heat exchanger 38 flows through chamber 44 into drain tube 46 to condensate trap assembly 48. As air blower 26 continues to urge a flow of air to be heated upwardly through heat exchanger assembly 18, heat energy is transferred from the combusted gas air mixture flowing through heat exchangers s 12~3.~5 30 and 38 to heat the air circulated by blower 26. Finally, the combusted gas air mixture that flows th~ough heat exchangers 30 and 38 exits through outlet 42 and is then delivered by inducer motor 22 through exhaust gas outlet S0 and thence to a vent pipe (not shown).

Cabinet 12 also ~ouses microproces~or control assembly S~, LED display 56, pressure tap 58 at primary heat exchanger inlet 60, pressure tap 62 at condensing heat exchanger outlet lo 42 and limit switch 64 disposed in air passage 52; the purposes of which will be explained in greater detail below.
If condensin~ furnace lo is replaced with a noncondensing-type furnace, then naturally pressure tap 62 would be disposed at primary heat exchanger outlet 34, since there would be no condensing heat exchanger 38.

Referring now to Figure 2, gas regulator 16 generally comprises valve body 66 having an inlet 68 and outlet 70.
Between inlet 68 and outlet 70 are a series of chambers, in particular, inlet chamber 72, intermediate chamber 74, regulator chamber 76, and main chamber 78. These chambers are in fluid communication, directly or indi~ectly, with valve body inlet 68 and outlet 70; inlet 68 communicates with inlet chamber 72 through inlet chamber seat 80, inlet chamber 7~ communicates with intermediate chamber 74 through intermediate chamber seat 82, intermediate chamber 74 communicates with regulator chamber 76 through regulator seat 84, regulator chamber 76 communicates with main chamber 78 through main seat 86, and main chamber 78 communicates with outlet 70. The use of the term "seat" is equivalent to terms such as "opening", "hole", and the like.

~ach of the above mentioned seats are closed and opened by particular members. Inlet chamber seat 80 is closed and opened by manually-operated valve head 88. Valve head 88 is connected to plunger 90, w~ich is slidably received through 6 ~ Z9 ~3 ~

valve body 66 in a flUid-tight manner. The externally remote end of plunger 90 is suitably connected to manual on-off lever 92, which is surrounded by indicator bracket 94.
Bracket 94 is connected to valve body 66 in an~J suitable manner. Spring 96 is disposed within inlet 68 and between valve head 88 and the valve top cover plate 91 so as to bias valve head 88 into seating engagement with inlet chamber seat 80, thereby to prevent fluid communication between inlet 68 and inlet chamber 72. O-ring 89 insures a fluid tight fit between valve head 88 and seat 80. To open or move valve head 88 to an open position to allow fluid communication between inlet 68 and inlet chamber 72, manual on-off lever 92 i8 rotated in a counter-clockwise direction, as viewed in Figure 2. Manual on-off lever 92 includes an enlarged end portion 98 that has a camming surface 100. Camming surface 100 is defined by two relatively flat surface~ 102 and 104 that are generally perpendicularly disposed to esch other and joined by a generally curved surface 106. As seen in Figure 2, manual lever 92 is in th2 clo~ed position so that spring 96 is biasing valve head 88 into seating engagement with inlet chamber ~eat 80 in a flui.d-tight manner. AB manual lever 92 is rotated counter-clockwi~e, the action of camming surface 100 and enlarged end portion 98 causes plunger 90 to be pulled upwardly against the force of sprlng 96 to separate valve head 88 from inlet chamber seat 80, thereby permitting fluid communication between inlet 68 and inlet chamber 72.
Manual lever 92 is held in ~he open position b~ the engaging force or friction existing between flat surface 102 and the flat exterior surface portion of valve body 66. Naturally, to close inlet chamber seat 80, manual lever 92 is rotated clockwise to permit spring 96 to extend plun~er 9O
downwardly, thereby per~itting valve head 88 to engage inlet chamber seat 80.
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Intermediate chamber seat 82 is opened and closed by valve seat disc 108, which is disposed in inlet chamber 72. Valve 7 l Z'343 ~S

seat disc 108 has a secondary plunger 110 oonnected thereto in any suitable manner and secondary plunger 110 is slidably received in bore 112 disposed in valve head 88 and plunger 90. Spring 114 is disposed in inlet chamber 7i between valve seat disc 108 and opposltely disposed inlet chamber upper surface 116. Spring 114 biases valve seat disc 108 downwardly to close intermediate chamber seat 82 in a fluid tight manner. A rubber portion 109 insures a fluid tight fit between disc 108 and seat 82. Valve se~t disc 108 is connected to secondary plunger 110 so that valve seat disc 108 moves in a generally vertical or straight line direction ~enerally perpendicular to the plane of intermediate chamber seat 82, thereby insuring a fluid tight closure of intermediate chamber seat 82 when valve seat dlsc 108 is in the closed po~ition, as illustrated in Figure 2. Disposed on the opposite side of valve seat disc 108 and in general axial alignment wlth secondary plunger 110 is push rod 118. Push rod 118 abuts against the undersurface of valve seat disc 108, and upon being moved in an upwardly direction, push rod 118 moves valve seat disc 108 upwardly against spring 114 to open intermediate chamber seat 82, thereby permitting fluid communication between inlet chamber 72 and intermediate chamber 74. Push rod 118 is moved in an up and down direction, as viewed in Figure 2, by pick and hold solenoid 120, Solenoid 120 is connected to valve body 66 in any suitable manner and includes a joining segment 122 extending slightly inwardly of intermediate chamber 74. Joining segment 122 provides a fluid tight fit or connection between solenoid 120 and intermediate chamber 74. Joining segment 122 has an axial passage 124 for slidably receiving push rod 118 therein, with the lower remote end of push rod 118 being fixed loosely to movable plunger 126 of solenoid 120. When solenoid 120 is in a de-energized state, plunger 126 and push rod 118 are located in a lowermost position, as illustrated in Figure 2, so that spring 114 biases valve seat disc 108 in fluid tight engagement with intermediate chamber seat 82.

8 1~29~ 5 Upon energizlng solenoid 120, plunger 126 and push rod 118 move upwardly against valve seat disc 1~8 and spring 11~, thereby to open intermediate chamber seat 82 to allow fluid communication between inlet chamber 72 and intèrmediate chamber 74.

The fluid communication between intermediate chamber 74, regulator chamber 76, and main chamber 78 are closely related in that the opening and closing of regulator seat 84 and main seat 86 are controlled by a single regulator valve disc 128 disposed in re~ulator chamber 76. It should be noted that regulator seat 84 and main Seat 86 are generally oppositely disposed from each other in regulator chamber 76 and are in generally axial alignment With each other, whereby the axial or linear movement of regulator valve disc 128 regulates the fluid communication between intermediate chamber 74, regulator chamber 76, and main chamber 78. Regulator valve disc 128 is connected in any suitable manner to regulator plunger 130 of regulator solenoid 132. A spring 134 is disposed against the underside of regulator valve disc 128 and through regulator seat 84, and biases regulator valve disc 128 upwardly to close main seat 86 in a-fluid tight iashion. The upper portion 136 of regulator valve disc 128 is made of a rubber material to ensure fluid tight engagement between valve di.sc 128 and main seat 86. Re~ulator valve disc 128 is moved downwardly from its uppermost position where it closes m~in seat 86 to a lowermost position where it closes regulator seat 84, thereby opening main seat 86 to permit fluid communication between regulator chamber 76 and main chamber 78. Regulator valve disc 128 is mo~ed to its lowermost position upon energizing regulator solenoid 132, which pulls regulator plunger 130 downwardly until valve disc 128 seats against regulator seat 84. By controlling the voltage to regulator olenoid 132, which will be explained in greater detail below, regulator valve disc 128 is positionable to an infinite number of positions between its 9 129~3 ~S

uppermost position where it closes main seat 86 and its lowermost position where it closes regulator seat 84.
Naturally, any position, other than the uppermost and lowermost positions, will provide simultaneous fluid communication between intermediate chamber 74, regulator chamber 76, and main chamber 78.

Disposed in fluid communication with intermediate chamber 74 are pilot filter 138 and pilot conduit 140 for respectively filtering the portion of the gas flowing through filter 138 and delivering it through pilot conduit 140 to the pilot flame assembly, which is part of gas regulator and pilot circuitry 16 (Figure 4).

A pressure-tap port 142 is disposed in regulator chamber 76 for transmitting variations in fluid pressure from chamber 76 through line 144 to pressure transducer 146. Pressure transducer 146 then generates an analog signal to microprocessor control 148 indicative of a change in fluid pressure in regulator chamber 76. Microprocessor control 148 is located in microprocessor control assembly 54 in condensing furnace 10, and is capable of being preprogrammed to generate a plurality of control signals in response to received input signals. Microprocessor control 148 is also connected electrically to thermostat 150 to receive signals therefrom, to pick and hold solenoid 120 by electrical lires 152, and to regulator solenoid 132 by electrical lines 154.

Referring to Figure 4, there is illustrated a simplified block diagram illustrating the interconnection between microprocessor control 148 and pressure ~aps 58, 62 through differential pressure tranqducer 156. As illustrated in Figure 2, differential pressure transducer 156 receives pressure tap inputs from pressure taps 58, 62 and generates an analog signal indicative of the differential pressure to microprocessor control 148 via electrical lines 158.

lo 1294345 Still referring to Figure 4, it can be seen that microprocessor control 148 is electrically connected to limit switch 64 (Figure 1), gas valve 16 through electrical lines 152, 154, air blower motor control 160 of air blower 26 through electrical lines 162, and inducer motor control 164 of inducer motor 22 through electrical lines 166. Air blower motor control 160 and inducer motor control 164 respectively control the rate of fluid flow created by air blower 26 and inducer wheel 24.
With the manual on-off lever 92 moved in a counter-clockwise position to open inlet chamber seat 80, and upon closing of contacts in thermostat 150 indicating a need for heat, microprocessor control 148 is programmed to send a signal via electrical lines 166 (Figure 4) to inducer motor control 164 to start inducer motor 22 to rotate inducer wheel 24, thereby causing a flow of combustion air through combustion air inlet 32, burner assembly 14, heat exchanger assembly 18, inducer housing 20, and out exhaust gas outlet 50. After a predetermined period of time, for example, ten seconds, to en~ure purging of the furnace, microprocessor control 148 generates a signal through electrical lines 152 to pick and hold solenoid 120, thereby energizing it to move plunger 126 upwardly so that push rod 118 separates valve seat disc 108 from intermediate chamber seat 82 to permit gas flow from inlet chamber 72 to intermediate chamber 74. The gas flows then to and through pilot filter 13~ and pilot conduit 140 to initiate the pilot flame, and flows also into regulator chamber 76 where the pressure is sensed at pressure-tap port 142. Ignition of the pilot flame is proved by the pilot circuitry in the pilot control of gas regulator 1~ and a signal is generated to microprocessor control 148 through electrical lines 152, 154 (Figure 4) to indicate the flame is proved.

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During this period of time, microprocessor control 148 ~Figure 2) is mon~toring the pressure drop across heat exchanger asse~bly 18, which is provided by pressure taps 58, 62 transmitting pressure readings to differential pressure transducer 156. Differential pressure transducer 156 sends a pressure differential signal through electrical lines 158 to micropro~essor control 148 indicati~e o~ the pressure drop reading. Pressure-tap port 142 is also transmitting increasing gas pressure in regulator chamber 76 through line 144 to pressure transducer 146, which generates an analog signal indicative of the increasing gas pressure to microprocessor control 148. After microprocessor control 148 determines a sufficient pressure drop exists across heat exchanger assembly 18, that the gas pressure in regulator chamber 76 is at or above a predetermined pressure, and the pilot flame has been proved, microprocessor control 148 is programmed to generate a voltage signal through electrical lines 154 to regulator solenoid 132. During this period of time, regulator valve disc 128 is closing off main seat 86 of main chamber 78 to prevent gas flow therethrough.

Because of the relatively high pressure existing in regulator chamber 76, the signal generated from microprocessor control 148 to regulator solenoid 132 is of a relatively high voltage to cause solenoid 132 to pull regul~tor plunger 130 to its lowermost position, whereby regulator ~alve disc 128 opens main seat 86 and closes regulator seat 84. This prevents fluid communication between regulator chamber 76 and intermediate chamber 74, but does permit fluid communication between regulator chamber 76 and main chamber 78. Thus, the increased gas pre~sure in regulator chamber 76 bleeds off through main seat 86, main chamber 78, and through outlet 70.
This decreasing gas pressure in regulator chamber 76 is continually monitored by microprocessor control 148 through port 14Z and upon reaching a predetermined low pressure, microproce~sor control 148 generates a relatively low voltage 12 ~2~4~ ~5 si~nal to regulator solenoid 132 to open regulator seat 84 by moving regulator plunger 130 and disc 128 to. an intermediate position between its uppermost position where it closes off main seat 86 and its lowermost position where it closes off regulator seat 84. Microprocessor control 148 is preprogrammed to position regulator valve disc 128 in regulator chamber 76 to provide a desired gas flow rate and pressure in main chamber 78.

Thereafter, gas flow is provided by gas regulator 16 to burner assembly 14 and the fuel air mixture is combusted by inshot burner 28. The combusted fuel air mixture is then drawn through heat exchanger assembly 18 and out exhaust gas outlet 50 by the rotation of inducer wheel 24 by mot~r 22.
After a preselected period of time, for example, one minute, to ensure heat exchanger assembly 18 has reached a predetermined temperature, microprocessor control 148 is preprogrammed to generate a signal through electrical lines 162 (Figure ~) to air blower motor control 160, which starts air blower 26 to provide a flow of air to be heated over condensing heat exchanger 38 and primary heat exchanger 30.
Any condensate that forms in condensing heat exchanger 38 is delivered through drain tube 46 to condensate trap assembly 48.
After the heating load has been satisfied, the contacts of thermostat 150 open, and in response thereto microprocessor control 148 de-energizes pick and hold solenoid 120 and regulstor solenold 132. Plunger 126 then moves downwardly, as viewed in Figure 2~ under the influence of spring 114, and valve seat disc 10~ closes intermediate chamber seat 82 due to the downwardly directed force provided by spring 114, thereby preventing fluid communication between inlet chamber 72 and intermediate chamber 74. In addition, upon de-energizing regulator solenoid 132, regulator plunger 130 moves upwardly under the influence of spring 134, and ~2~43 ~
regulator ~alve di6c 128 is moved to its uppermost position under the force exerted by spring 134 to thereby clo~e off main seat 86. Thu~, both intermediate chamber sea~ 82 and main seat 86 are-closed to prevent gas flow through gas regulator 16. This naturally cause8 the pilot flame and burner flame to be e~tinguished, and upon cooling down of the pilot assembly, all switches are reset.

After regulator solenoid 132 is de-energi~.ed, microprocessor control 148 generates a slgnal over electrical llnes 166 to lnducer motor control 16~ to terminate operation of inducer motor 22. After inducer motor 22 has been de-energized, microprocessor control 148 is further preprogrammed to generate a signal over lines 162 to air blower motor control 160, thereby terminating operation of air blower 26, after a preselected period of time, for example, 60-240 seconds.
This continual running of air blower 26 for this predetermined amount of time permits further heat transfer between the air to be heated and the heat being generated through heat exchanger asse~bly 18, which also naturally serves to cool heat exchanger assembly 18.

Because the pre~sure drop aCro~8 heat exchanger ~ssembly 18 can vary due to changing conditlons or parameters, mi~roprocessor control 148 i~ preprogrammed to ensure an opt~mum manlold gas pressure a8 a function of the a~ount of combustion a~r ~low~ng through combustion air inlet 32 under the influence of inducer wheel 24. The pres.~ure drop across heat exchanger assembly 18 is measured by pressure taps 58, 62 which transmit their individual pressure readings to differential pressure transducer 156 (Figures 1 and 2).
Transducer 156 then generates a pressure differential signal to microprocessor control 148 over electrical lines 158 indicative of the pressure drop across heat exchanger assembly 1~, Figure 3 illustrates a plot or graph of an empirically determined equation for optimum manifold gas 1~
~129~3~5 pressure versus heat exchanger pressure drop. Although the graph is a straight line, it can be of any geometry, such as a curved line. Irregardles~ of the shape of the line, the graph represents that for one heat e~changer pressure drop value, there is one optimum mani:Eold gas pressure. This equation, as represented by Figure 3, is programmed into microprocessor control 148 whereby it determines the optimum manifold gas pressure for a particular pressure drop across heat exchanger assembly 18, as indicated by the pressure differential signal received from differential pressure transducer 156. As the pressure drop varies, microprocessor control 148 generates a signal over electrical lines 154 to regulator solenoid 132, which moves regulator valve disc 128 relative to main seat 86 to provide the desired gas flow rate through main seat 86 and outlet 70. During continued operation of furnace 10, microprocessor control 148 continues to make ad~ustments in the gas flow rate and pressure as a function of heat exchanger pressure drop. Thus, gas regulator 16 and microprocessor control 148 can provide essentially an infinite number of gas flow rates between a zero flow rate and a maximum flow rate in a selected range of, for example, two inches - fourteen inches W.C.

Manual on-off lever 92 is made of a ~eltable material that will melt at a de8ired temperature. Thus, if for some reason the temperature in cabinet 12 should exceed a de~ired temperature, lever 92 will melt to allow spring 96 to move valve head 88 downwardly to close inlet chamber seat 80, thereby preventing gas flow through regulator 16.
The principles of operation of gas regulator 16 can also be applied in controlling other fluid5, such as the flow rate of refrigerant in a refrigeration system.

While this invention has been described as having a preferred embodiment, it will be understood that it is capable of ~ Z~9h~5 further modifications. This application is therefore intended to cover any variations, uses, or adaptations of the invention following the general principles thereof, and including such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and fall within the limits of the appended claims.

Claims (20)

1. A fluid flow control device, comprising:
a housing having an inlet and an outlet, a regulator chamber in said housing and having a regulator opening and a main opening, said regulating chamber being fluidly communicable with said housing inlet and outlet through said regulator opening and said main opening, respectively, a regulator disc member in said regulator chamber and being selectively positionable to any one of a plurality of positions between a first position wherein said regulator disc member closes said main opening and a second position wherein said regulator disc member closes said regulator opening, a pressure-sensing means in said regulator chamber for sensing variations of fluid pressure in said regulator chamber, and an actuating means operatively connected between said pressure-sensing means and said regulator disc member for receiving sensed variations in the fluid pressure from said pressure-sensing means and for selectively positioning said regulator disc member in response to the fluid pressure variation, whereby the flow rate of a fluid through said housing is selectively controlled between a zero flow rate and a maximum flow rate.

2. The device of claim 1 further comprising a pressure transducer means operatively connected between said pressure-sensing means and said actuating means for receiving sensed variations in pressure from said pressure-sensing means and for generating a first electrical signal in response thereto to said actuating means.

3. The device of claim 2 wherein said actuating means includes a programmable microprocessor means for receiving said first electrical signal from said pressure transducer means and for generating a second electrical signal in response thereto to selectively position said regulator disc member.

4. The device of claim 3 wherein said actuating means further includes a coil means operatively connected between said programmable microprocessor means and said regulator disc member for receiving said second electrical signal from said programmable microprocessor means and for selectively positioning said regulator disc member in response thereto.

5. The device of claim 1 wherein said regulator opening and said main opening are in axial alignment, and said regulator disc member moves linearly therebetween.

6. The device of claim 1 further comprising a manually operated valve means disposed generally between said housing inlet and said housing outlet for manually controlling fluid communication therebetween.

7. The device of claim 6 wherein said manually operated valve means includes a valve disc member movable between a closed position wherein said valve disc member prevents fluid communication between said housing inlet and said housing outlet, and an open position wherein said valve disc member permits fluid communication between said housing inlet and said housing outlet, a manually operated switch member disposed externally of said housing and connected to said valve disc member for moving said valve disc member between said closed and said open positions, and a bias means for biasing said valve disc member to said closed position.

8. The device of claim 7 wherein said manually operated switch member is made of a meltable material that melts at a predetermined temperature, whereby when said manually operated switch member melts at said predetermined temperature, said bias means moves said valve disc member to said closed position.

9. A fluid flow control device, comprising:
a housing having an inlet and an outlet, a regulator chamber in said housing and having a regulator opening and a main opening, said regulator chamber being fluidly communicable with said housing inlet and said housing outlet through said regulator opening and said main opening, respectively, and a regulator disc member in said regulator chamber and being selectively positionable to any one of a plurality of positions between a first position wherein said regulator disc member closes said main opening and a second position wherein said regulator disc member closes said regulator opening for controlling the flow rate of a fluid through said housing between a zero flow rate and a maximum flow rate.

10. The device of claim 9 further comprising:
a fluid flow detecting means in said regulator chamber for detecting fluid pressure in said regulator chamber, and an actuating means operatively connected between said fluid flow detecting means and said regulator disc member for receiving detected variations in the fluid pressure from said fluid flow detecting means and for selectively positioning said regulator disc member in response to the fluid pressure variation.

11. The device of claim 10 further comprising a pressure transducer means operatively connected between said fluid flow detecting means and said actuating means for receiving detected variations in pressure from said fluid flow detecting means and for generating a first electrical signal in response thereto to said actuating means.

12. The device of claim 11 wherein said actuating means includes a programmable microprocessor means for receiving said first electrical signal from said pressure transducer means and for generating a second electrical signal in response thereto, and a coil means operatively connected between said programmable microprocessor means and said regulator disc member for receiving said second electrical signal from said programmable microprocessor means and for selectively positioning said regulator disc member in response thereto.

13. The device of claim 9 wherein said regulator opening and said main opening are in axial alignment, and said regulator disc member moves linearly therebetween.

14. A fluid flow control device, comprising:
a housing having an inlet and an outlet, an intermediate chamber in said housing and having a chamber inlet and a chamber outlet, said intermediate chamber being fluidly communicable with said housing inlet through said chamber inlet, an intermediate disc member at said intermediate chamber inlet and being positionable to open and close said intermediate chamber inlet, a regulator chamber in said housing and having a regulator opening and a main opening, said regulator chamber being fluidly communicable with said intermediate chamber through said regulator opening and said intermediate chamber outlet, and being fluidly communicable with said housing outlet through said main opening, a regulator disc member in said regulator chamber and being selectively positionable to any one of a plurality of positions between a first position wherein said regulator disc member closes said main opening and a second position wherein said regulator disc member closes said regulator opening, a pressure detecting means in said regulator chamber for detecting variations of fluid pressure in said regulator chamber and generating a signal in response thereto, and a microprocessor control means operatively connected to said pressure-detecting means, said intermediate disc member, and said regulator disc member for receiving said generated signal from said pressure detecting means and for selectively positioning said regulator disc member in response thereto, whereby the flow rate of a fluid through said housing is selectively controlled between a zero flow rate and a maximum flow rate.

15. The device of claim 14 wherein said regulator opening and said main opening are in axial alignment, and said regulator disc member moves linearly therebetween.

16. The device of claim 14 further comprising a manually operated valve means disposed generally between said housing inlet and said intermediate chamber inlet for manually controlling the flow of fluid therebetween.

17. The device of claim 16 wherein said manually operated valve means includes a valve disc member movable between a closed position wherein said valve disc member prevents fluid communication between said housing inlet and said intermediate chamber and an open position wherein said valve disc member permits fluid communication between said housing inlet and said intermediate chamber, a manually operated switch member disposed externally of said housing and connected to said valve disc member for moving said valve disc member between said closed and said open positions, and a bias means for biasing said valve disc member to said closed position, said manually operated switch member being made of a meltable material that melts at a predetermined temperature, whereby when said manually operated switch member melts at said predetermined temperature, said bias means moves said valve disc member to said closed position to prevent fluid communication between said housing inlet and said regulator opening.

18. A method of controlling the flow rate of a fluid through a housing having an inlet and an outlet comprising the steps of:
providing a regulator chamber in the housing and having a regulator opening and a main opening, the regulator chamber being fluidly communicable with the housing inlet and outlet through the regulator opening and the main opening, respectively, providing a regulator disc member in the regulator chamber and being selectively movable to any one of a plurality of positions between a first position wherein the regulator disc member closes the main opening and a second position wherein the regulator disc member closes the regulator opening, supplying a flow of fluid through the housing inlet and regulator opening into the regulator chamber, sensing an increase in fluid pressure in the regulator chamber, at a predetermined first pressure in the regulator chamber, moving the regulator disc member from the first position to the second position, thereby preventing fluid communication between the regulator chamber and the housing inlet and permitting fluid communication between the regulator chamber and housing outlet to permit the fluid in the regulator chamber to flow out the housing outlet, sensing the decrease in fluid pressure in the regulator chamber, and at a predetermined second pressure, selectively moving the regulator disc member to a selected one of the plurality of positions between the first and second positions to provide a desired flow rate of fluid through the housing.

19. The method of claim 18 further comprising the steps of continuing to sense any variations in fluid pressure in the regulator chamber, and selectively moving the regulator disc member to one of the plurality of positions between the first and second positions to maintain the. flow rate of fluid as desired.

20. The method of claim 19 further comprising the steps of moving the regulator disc member to the first position, terminating the supply of fluid flow, continuing to sense fluid pressure in the regulator chamber caused by undesired fluid flow, and upon sensing an undesired flow of fluid, manually shutting off the housing inlet.