Safety valve and system for hydrocarbon storage tanks

Claim 2

A safety system for a hydrocarbon storage tank having a floating roof, a water drain in said roof, a drain opening from said tank, and a flexible line connecting said roof drain to said tank drain for carrying off rain water collected on said floating roof and preventing leakage of hydrocarbon liquid and through said tank drain, said system comprising; an electrically-operated, normally-closed valve means connected in said tank drain, means responsive to pressure in said system exceeding a predetermined amount to maintain said valve means in a closed position for safety purposes until overridden, means responsive to the electrical conductivity of liquid on the inlet side of said valve means to detect the presence of water therein, and electric circuit means interconnecting said conductivity-responsive means and said electrically-operated valve means and operable to energize said valve means to open the same on detection of the presence of water in the inlet thereto.

Claim 3

A safety system for a hydrocarbon storage tank having a floating roof, a water drain in said roof, a drain opening from said tank, and a flexible line connecting said roof drain to said tank drain for carrying off rain water collected on said floating roof and preventing leakage of hydrocarbon liquid and through said tank drain, said system comprising; an electrically-operated, normally-closed valve means connected to said tank drain, means responsive to the electrical conductivity of liquid on the inlet side of said valve means to detect the presence of water therein, electric circuit means interconnecting said conductivity-responsive means and said electrically-operated valve means and operable to energize said valve means to open the same on detection of the presence of water in the inlet thereto, a primary power supply for operating said valve means, a secondary power supply operative in responsive to the failure of said primary power supply for operating said valve means, and an external power source for continuously charging said primary and secondary power supply.

Claim 4

A safety system for a hydrocarbon storage tank having a floating roof, a water drain in said roof, a drain opening from said tank, and a flexible line connecting said roof drain to said tank drain for carrying off rain water collected on said floating roof and preventing leakage of hydrocarbon liquid and through said tank drain, said system comprising; an electrically-operated, normally-closed valve means connected to said tank drain, means responsive to the electrical conductivity of liquid on the inlet side of said valve means to detect the presence of water therein, electric circuit means interconnecting said conductivity-responsive means and said electrically-operated valve means and operable to energize said valve means to open the same on detection of the presence of water in the inlet thereto, a primary power supply for operating said valve means, a secondary power supply operative in responsive to the failure of said primary power supply for operating said valve means, and an external power source for continuously charging said primary and secondary power supply.

Claim 5

A system according to claim 2 in which said external power source comprises solar electric power generating means supported adjacent to said system.

Claim 6

A system according to claim 2 including means responsive to the operation of said secondary power supply for signaling its operation and maintaining said valve means in a closed position, and means responsive to the pressure in said system exceeding a predetermined limit for maintaining said valve means in a closed position.

Claim 7

A system according to claim 4 in which said means responsive to electrical conductivity for detecting the presence of water in said drain line comprises a pair of electrodes extending into the interior of the inlet of said valve means, means connecting a source of direct current between said electrodes, and means responsive to the flow of current between said electrodes through said water.

Claim 8

A system according to claim 4 in which means sensing the pressure in such system comprises pressure sensing means in communication with the interior of the inlet of said valve means, means connecting a source of direct current to said device, and means responsive to the pressure above a predetermined level for by-passing said means for continuously measuring electrical conductivity.

Claim 9

A system according to claim 2 in which said primary power supply comprises a storage battery.

Claim 10

A system according to claim 2 in which said secondary power supply comprises a storage battery.

Claim 11

A system according to claim 2 in which said electrically operated valve means comprises a gate valve and electric motor operatively connected thereto.

Claim 12

A system according to claim 2 including a timing circuit operable to limit the time that said electrically operated valve means is energized to selected time intervals.

Claim 13

A system according to claim 2 in which said secondary source of power includes two alternate power sources, and circuit means for detecting a selected decrease in power from one of said alternate power sources and switching to said other power source.

Claim 14

A system according to claim 2 in which said secondary source of power includes two alternate power sources, circuit means for detecting a selected decrease in power from one of said alternate power sources and switching to said other power source, and a timing circuit operable to limit the time that said electrically operated valve means is energized to selected time intervals.

Claim 15

A system according to claim 2 including a normally-open, motor-operated gate valve positioned in said drain, an electric motor operatively connected to said valve and operable to open and close the same, a pair of sensors positioned in the inlet to said valve to detect electric conductivity of liquid therein and permitting a flow of current when immersed in water, an electric relay connected to said motor and operable to energize said motor to move said valve to an open or a closed position, a plurality of NOR gates and a field effect transistor interconnected in circuit with said sensors and said relay and operable on current flow between said sensors in the presence of water to actuate said relay to energize said motor to open said valve and operable in the absence of current flow between said sensors to energize said motor to close said valve.

Claim 16

A system according to claim 13 including pressure responsive means positioned in the inlet to said valve to respond to pressure therein and including means operatively connected to one of said NOR gates whereby the occurrence of a selected pressure effects operation of said relay to energize said motor to close said valve.

Claim 17

A system according to claim 13 including a signal flag, an electric solenoid operatively connected to said signal flag to operate the same, a second electric relay connected in circuit with said solenoid and said NOR gates and operable in response to energization of said first relay for closing said valve to energize said solenoid to move said flag to provide a visual signal of the valve closing.

Claim 18

A system according to claim 13 in which one of said NOR gates has its output connected to the collector of said transistor and has its input from said sensors, one additional NOR gate and an OR gate being connected in series, said pressure responsive means being connected to one input to said first NOR gate, and the output from said one NOR gate being connected to the other input to said first NOR gate.

Claim 19

A system according to claim 13 including a signal flag, an electric solenoid operatively connected to said signal flag to operate the same, one of said NOR gates has its output connected to the collector of said transistor and has its input from said sensors, three additional NOR gates being connected in series with the output from the first and second gate being connected to the input to the second and third gates, said pressure responsive means being connected to one input to said first NOR gate, the output from said one NOR gate being connected to the other input to said first NOR gate, and a second electric relay connected in circuit with said solenoid and said third NOR gate and operable in response to energization of said first relay for closing said valve to energize said solenoid to move said flag to provide a visual signal of the valve closing.

Claim 20

A system according to claim 13 including a primary direct current battery connected to provide current for said system, a secondary direct current battery connected to provide current for said system, a switch connected to said batteries to select the battery supplying current to said system, and solar electric powr generating means connected to said batteries to charge the same.

Claim 21

A system according to claim 2 including a normally-open, motor-operated gate valve positioned in said drain, an electric motor operatively connected to said valve and operable to open and close the same, a pair of sensors positioned in the inlet to said valve to detect electric conductivity of liquid therein and permitting a flow of current when immersed in water, an electric relay connected to said motor and operable to energize said motor to move said valve to an open or a closed position, a plurality of NOR gates, an OR gate, and a field effect transistor interconnected in circuit with said sensors and said relay and operable on current flow between said sensors in the presence of water to actuate said relay to energize said motor to open said valve and operable in the absence of current flow between said sensors to energize said motor to close said valve.

Claim 22

A system according to claim 19 including pressure responsive means positioned in the inlet to said valve to respond to pressure therein and including means operatively connected to one of said NOR gates whereby the occurrence of a selected pressure effects operation of said relay to energize said motor to close said valve.

Claim 23

A system according to claim 19 including a signal flag, an electric solenoid operatively connected to said signal flag to operate the same, a second electric relay connected in circuit with said solenoid and said one NOR gate and said OR gate and operable in response to energization said solenoid to move said flag to provide a visual signal of the valve closing.

Claim 24

A system according to claim 19 in which one of said NOR gates has its output connected to the collector of said transistor and has its input from said sensors, one of said NOR gates and said OR gate being connected in series, said pressure responsive means being connected to one input to said first NOR gate, and the output from said one NOR gate being connected to the other input to said first NOR gate.

Claim 25

A system according to claim 19 including a signal flag, an electric solenoid operatively connected to said signal flag to operate the same, one of said NOR gates has its output connected to the collector of said transistor and has its input from said sensors, one of said NOR gates and said OR gate being connected in series with the output from said NOR gate being connected to the input to said OR gate, said pressure responsive means being connected to one input to said first NOR gate, the output from said one NOR gate being connected to the other input to said first NOR gate, and a second electric relay connected in circuit with said solenoid and said OR gate and operable in response to energization of said first relay for closing said valve to energize said solenoid to move said flag to provide a visual signal of the valve closing.

Claim 26

A system according to claim 19 including a primary direct current battery connected to provide current for said system, a secondary direct current battery connected to provide current for said system, a switch connected to said batteries to select the battery supplying current to said system, and solar electric power generating means connected to said batteries to charge the same.

Claim 27

A safety valve apparatus for use in a system for a hydrocarbon storage tank having a floating roof, a water drain in said roof, a drain opening from said tank, and a flexible line connecting said roof drain to said tank drain for carrying off rain water collected on said floating roof and preventing leakage of hydrocarbon liquid and through said tank drain, said apparatus comprising; an electrically-operated, normally-closed valve means adapted to be connected in said tank drain, means responsive to pressure in said system exceeding a predetermined amount to maintain said valve means in a closed position for safety purposes until overridden, means responsive to the electrical conductivity of liquid on the inlet side of said valve means to detect the presence of water therein, and electric circuit means interconnecting said conductivity-responsive means and said electrically-operated valve means and operable to energize said valve means to open the same on detection of the presence of water in the inlet thereto.

Claim 28

A safety valve apparatus for use in a system for a hydrocarbon storage tank having a floating roof, a water drain in said roof, a drain opening from said tank, and a flexible line connecting said roof drain to said tank drain for carrying off rain water collected on said floating roof and preventing leakage of hydrocarbon liquid and through said tank drain, said apparatus comprising; an electrically-operated, normally-closed valve means adapted to be connected in said tank drain, means responsive to pressure in said system exceeding a predetermined amount to maintain said valve means in a closed position for safety purposes until overridden, means responsive to the electrical conductivity of liquid on the inlet side of said valve means to detect the presence of water therein, and electric circuit means interconnecting said conductivity-responsive means and said electrically-operated valve means and operable to energize said valve means to open the same on detection of the presence of water in the inlet thereto.

Claim 29

A safety valve apparatus for use in a system for a hydrocarbon storage tank having a floating roof, a water drain in said roof, a drain opening from said tank, and a flexible line connecting said roof drain to said tank drain for carrying off rain water collected on said floating roof and preventing leakage of hydrocarbon liquid and through said tank drain, said apparatus comprising; an electrically-operated, normally-closed valve means adapted to be connected in said tank drain, means responsive to the electrical conductivity of liquid on the inlet side of said valve means to detect the presence of water therein, electric circuit means interconnecting said conductivity-responsive means and said electrically-operated valve means and operable to energize and valve means to open the same on detection of the presence of water in the inlet thereto, a primary power supply for operating said valve means, a secondary power supply operative in responsive to the failure of said primary power supply for operating said valve means, and means adapted to be connected to an external power source for continuously charging said primary and secondary power supply.

Claim 30

A safety valve apparatus for use in a system for a hydrocarbon storage tank having a floating roof, a water drain in said roof, a drain opening from said tank, and a flexible line connecting said roof drain to said tank drain for carrying off rain water collected on said floating roof and preventing leakage of hydrocarbon liquid and through said tank drain, said apparatus comprising; an electrically-operated, normally-closed valve means adapted to be connected in said tank drain, means responsive to the electrical conductivity of liquid on the inlet side of said valve means to detect the presence of water therein, electric circuit means interconnecting said conductivity-responsive means and said electrically-operated valve means and operable to energize and valve means to open the same on detection of the presence of water in the inlet thereto, a primary power supply for operating said valve means, a secondary power supply operative in responsive to the failure of said primary power supply for operating said valve means, and means adapted to be connected to an external power source for continuously charging said primary and secondary power supply.

Claim 31

A valve apparatus according to claim 26 including means responsive to the operation of said secondary power supply for signaling its operation and maintaining said valve means in a closed position, and means responsive to the pressure in said valve means exceeding a predetermined limit for maintaining the same in a closed position.

Claim 32

A valve apparatus according to claim 27 in which said means responsive to electrical conductivity for detecting the presence of water in said drain line comprises a pair of electrodes extending into the interior of the inlet of said valve means, means connecting a source of direct current between said electrodes, and means responsive to the flow of current between said electrodes through said water.

Claim 33

A valve apparatus according to claim 27 in which said means sensing the pressure in said valve means comprises pressure sensing means in communication with the interior of the inlet of said valve means, means connecting a source of direct current to said device, and means responsive to the pressure above a predetermined level for by-passing said means for continuously measuring electrical conductivity.

Claim 34

A valve apparatus according to claim 26 in which said primary and secondary power supplies comprise storage batteries.

Claim 35

A valve apparatus according to claim 26 in which said electrically operated valve means comprises a gate valve and electric motor operatively connected thereto.

Claim 36

A safety valve apparatus for use in a system for a hydrocarbon storage tank having a floating roof, a water drain in said roof, a drain opening from said tank, and a flexible line connecting said roof drain to said tank drain for carrying off rain water collected on said floating roof and preventing leakage of hydrocarbon liquid and through said tank drain, said apparatus comprising; an electrically-operated, normally-closed valve means adapted to be connected in said tank drain, means responsive to the electrical conductivity of liquid on the inlet side of said valve means to detect the presence of water therein, and electric circuit means interconnecting said conductivity-responsive means and said electrically-operated valve means and operable to energize said valve means to open the same on detection of the presence of water in the inlet thereto, a normally-open, motor-operated gate valve adapted to be positioned in said drain, an electric motor operatively connected to said valve and operable to open and close the same, a pair of sensors adapted to be positioned in the inlet to said valve to detect electric conductivity of liquid therein and permitting a flow of current when immersed in water, an electric relay adaptedto be connected to said motor and operable to energize said motor to move said valve to an open or a closed position, a plurality of NOR gates and a field effect transistor interconnected in circuit with said sensors and said relay and operable on current flow between said sensors in the presence of water to actuate said relay to energize said motor to open said valve and operable in the absence of current flow between said sensors to energize said motor to close said valve.

Claim 37

A safety valve apparatus for use in a system for a hydrocarbon storage tank having a floating roof, a water drain in said roof, a drain opening from said tank, and a flexible line connecting said roof drain to said tank drain for carrying off rain water collected on said floating roof and preventing leakage of hydrocarbon liquid and through said tank drain, said apparatus comprising; an electrically-operated, normally-closed valve means adapted to be connected in said tank drain, means responsive to the electrical conductivity of liquid on the inlet side of said valve means to detect the presence of water therein, and electric circuit means interconnecting said conductivity-responsive means and said electrically-operated valve means and operable to energize said valve means to open the same on detection of the presence of water in the inlet thereto, a normally-open, motor-operated gate valve adapted to be positioned in said drain, an electric motor operatively connected to said valve and operable to open and close the same, a pair of sensors adapted to be positioned in the inlet to said valve to detect electric conductivity of liquid therein and permitting a flow of current when immersed in water, an electric relay adaptedto be connected to said motor and operable to energize said motor to move said valve to an open or a closed position, a plurality of NOR gates and a field effect transistor interconnected in circuit with said sensors and said relay and operable on current flow between said sensors in the presence of water to actuate said relay to energize said motor to open said valve and operable in the absence of current flow between said sensors to energize said motor to close said valve.

Claim 38

A valve apparatus according to claim 32 including pressure responsive means positioned in the inlet to said valve to respond to pressure therein and including means operatively connected to one of said NOR gates whereby the occurrence of a selected pressure effects operation of said relay to energize said motor to close said valve.

Claim 39

A valve apparatus according to claim 32 including a signal flag, an electric solenoid operatively connected to said signal flag to operate the same, a second electric relay connected in circuit with said solenoid and said NOR gates and operable in response to energization of said first relay for closing said valve to energize said solenoid to move said flag to provide a visual signal of the valve closing.

Claim 40

A valve apparatus according to claim 33 in which one of said NOR gates has its output connected to the collector of said transistor and has its input from said sensors, three additional NOR gates being connected in series with the output from the first and second gate being connected to the input to the second and third gates, said pressure responsive means being connected to one input to said first NOR gate, and the output from said one NOR gate being connected to the other input to said first NOR gate.

Claim 41

A valve apparatus according to claim 33 including a signal flag, an electric solenoid operatively connected to said signal flag to operate the same, one of said NOR gates has its output connected to the collector of said transistor and has its input from said sensors, three additional NOR gates being connected in series with the output from the first and second gate being connected to the input to the second and third gates, said pressure responsive means being connected to one input to said first NOR gate, the output from said one NOR gate being connected to the other input to said first NOR gate, and a second electric relay connected in circuit with said solenoid and said third NOR gate and operable in response to energization of said first relay for closing said valve to energize said solenoid to move said flag to provide a visual signal of the valve closing.

Claim 42

A safety valve apparatus for use in a system for a hydrocarbon storage tank having a floating roof, a water drain in said roof, a drain opening from said tank, and a flexible line connecting said roof drain to said tank drain for carrying off rain water collected on said floating roof and preventing leakage of hydrocarbon liquid and through said tank drain, said apparatus comprising; an electrically-operated, normally-closed valve means adapted to be connected in said tank drain, means responsive to the electrical conductivity of liquid on the inlet side of said valve means to detect the presence of water therein, and electric circuit means interconnecting said conductivity-responsive means and said electrically-operated valve means and operable to energize said valve means to open the same on detection of the presence of water in the inlet thereto, a normally-open, motor-operated gate valve adapted to be positioned in said drain, an electric motor operatively connected to said valve and operable to open and close the same, a pair of sensors adapted to be positioned in the inlet to said valve to detect electric conductivity of liquid therein and permitting a flow of current when immersed in water, an electric relay connected to said motor and operable to energize said motor to move said valve to an open or a closed position, a plurality of NOR gates, an OR gate, and a field effect transistor interconnected in circuit with said sensors and said relay and operable on current flow between said sensors in the presence of water to actuate said relay to energize said motor to open said valve and operable in the absence of current flow between said sensors to energize said motor to close said valve.

Claim 43

A safety valve apparatus for use in a system for a hydrocarbon storage tank having a floating roof, a water drain in said roof, a drain opening from said tank, and a flexible line connecting said roof drain to said tank drain for carrying off rain water collected on said floating roof and preventing leakage of hydrocarbon liquid and through said tank drain, said apparatus comprising; an electrically-operated, normally-closed valve means adapted to be connected in said tank drain, means responsive to the electrical conductivity of liquid on the inlet side of said valve means to detect the presence of water therein, and electric circuit means interconnecting said conductivity-responsive means and said electrically-operated valve means and operable to energize said valve means to open the same on detection of the presence of water in the inlet thereto, a normally-open, motor-operated gate valve adapted to be positioned in said drain, an electric motor operatively connected to said valve and operable to open and close the same, a pair of sensors adapted to be positioned in the inlet to said valve to detect electric conductivity of liquid therein and permitting a flow of current when immersed in water, an electric relay connected to said motor and operable to energize said motor to move said valve to an open or a closed position, a plurality of NOR gates, an OR gate, and a field effect transistor interconnected in circuit with said sensors and said relay and operable on current flow between said sensors in the presence of water to actuate said relay to energize said motor to open said valve and operable in the absence of current flow between said sensors to energize said motor to close said valve.