Method and apparatus for on-line detection of leaky emergency shut down or other valves
First Claim
1. An apparatus for use with a fluid transport system having an upstream pipe, a downstream pipe and a valve connected between the upstream pipe and the downstream pipe for controlling fluid flow through the system, the valve having at least one upstream seal, at least one downstream seal and an inner cavity effectively isolated by the seals from the fluid flow stream, the apparatus for detecting a leak in at least one of the seals, the apparatus comprising:
- a first transducer in fluid communication with the fluid flow stream at at least one of;
(1) a predetermined distance upstream of the upstream seal and, (2) a predetermined distance downstream of the downstream seal, the first transducer for sensing pressure pulsations resulting from at least one of;
(1) dynamic energy due to fluid flow through the fluid transport system and, (2) transient energy within the fluid in the transport system after the valve is closed, and for generating first representative electrical signals as a function of time;
a second transducer in fluid communication with the inner cavity for sensing substantially simultaneous pressure pulsations within the inner cavity and for generating second representative electrical signals as a function of time; and
an analyzer for receiving the first and second electrical signals and for generating at least one of the following functions;
(1) a frequency response function and, (2) a coherence function, the generated function being sufficiently averaged to provide a meaningful measure of the degree to which the two electrical signals are related to thereby indicate whether, and to what extent, sensed pressure pulsations within the fluid transport system are passing through at least one of the seals to the inner cavity.
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0 Petitions
Accused Products
Abstract
A method and apparatus for on-line detection of leaky emergency shutdown or other valves in a fluid transport system having an upstream pipe, a downstream pipe and the valve connected between the upstream pipe and the downstream pipe for controlling fluid flow through the system. The valve has at least one upstream seal and at least one downstream seal and an inner cavity effectively isolated by the seals from the fluid flow stream through the system. The apparatus comprises a first transducer in fluid communication with the fluid flow stream at at least one of: a predetermined distance upstream of the upstream seal; and a predetermined distance downstream of the downstream seal. The first transducer is for sensing pressure pulsations resulting from at least one of: dynamic energy due to fluid flow through the transport system; and transient energy within the fluid in the transport system after the valve is closed and for generating representative electrical signals as a function of time. A second transducer is in fluid communication with the inner cavity of the valve for sensing substantially simultaneous pressure pulsations within the inner cavity and for generating second representative electrical signals as a function of time. An analyzer receives the first and second electrical signals and generates at least one of: a frequency response function; and a coherence function. The generated function is sufficiently averaged to provide a meaningful measure of the degree to which the two electrical signals are related to thereby indicate whether, and to what extent, sensed pressure pulsations within the fluid transport system are passed through at least one of the seals to the inner cavity.
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Citations
28 Claims
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1. An apparatus for use with a fluid transport system having an upstream pipe, a downstream pipe and a valve connected between the upstream pipe and the downstream pipe for controlling fluid flow through the system, the valve having at least one upstream seal, at least one downstream seal and an inner cavity effectively isolated by the seals from the fluid flow stream, the apparatus for detecting a leak in at least one of the seals, the apparatus comprising:
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a first transducer in fluid communication with the fluid flow stream at at least one of;
(1) a predetermined distance upstream of the upstream seal and, (2) a predetermined distance downstream of the downstream seal, the first transducer for sensing pressure pulsations resulting from at least one of;
(1) dynamic energy due to fluid flow through the fluid transport system and, (2) transient energy within the fluid in the transport system after the valve is closed, and for generating first representative electrical signals as a function of time;a second transducer in fluid communication with the inner cavity for sensing substantially simultaneous pressure pulsations within the inner cavity and for generating second representative electrical signals as a function of time; and an analyzer for receiving the first and second electrical signals and for generating at least one of the following functions;
(1) a frequency response function and, (2) a coherence function, the generated function being sufficiently averaged to provide a meaningful measure of the degree to which the two electrical signals are related to thereby indicate whether, and to what extent, sensed pressure pulsations within the fluid transport system are passing through at least one of the seals to the inner cavity. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for use with a fluid transport system having an upstream pipe, a downstream pipe and a valve connected between the upstream pipe and the downstream pipe for controlling fluid flow through the system, the valve having at least one upstream seal, at least one downstream seal and an inner cavity effectively isolated by the seals from the fluid flow stream, the apparatus for detecting and identifying the location of a leak in at least one of the seals when the valve is closed, the apparatus comprising:
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an external sound source in fluid communication with the fluid transport system for generating sound energy within the system; a first transducer in fluid communication with the fluid in the system at at least one of;
(1) a predetermined distance upstream of the upstream seal and, (2) a predetermined distance downstream of the downstream seal, the first transducer for sensing pressure pulsations resulting from the acoustic energy generated by the sound source and for generating first representative electrical signals as a function of time;a second transducer in fluid communication with the inner cavity for sensing substantially simultaneous pressure pulsations within the inner cavity resulting from the acoustic energy generated by the sound source and for generating second representative electrical signals as a function of time; and an analyzer for receiving the first and second electrical signals and for generating at least one of the following functions;
(1) a frequency response function and, (2) a coherence function, the generated function being sufficiently averaged to provide a meaningful measure of the degree to which the two electrical signals are related to thereby indicate whether, and to what extent, sensed pressure pulsations within the fluid transport system are passing through at least one of the seals to the inner cavity. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method for use with a fluid transport system having an upstream pipe, a downstream pipe and a valve connected between the upstream pipe and the downstream pipe for controlling fluid flow through the system, the valve having at least one upstream seal, at least one downstream seal and an inner cavity effectively isolated by the seals from the fluid flow stream, the method for detecting a leak in at least one of the seals, comprising the steps of:
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sensing pressure pulsations within the fluid flow stream at at least one of;
(1) a predetermined distance upstream of the upstream seal and, (2) a predetermined distance downstream of the downstream seal and generating first representative electrical signals as a function of time, the pressure pulsations resulting from at least one of;
(1) a dynamic energy due to fluid flow through the fluid transport system and, (2) transient energy within the fluid in the transport system after the valve is closed;sensing substantially simultaneous pressure pulsations within the inner cavity and generating second representative electrical signals as a function of time; and analyzing the first and second electrical signals and generating at least one of the following functions;
(1) a frequency response function and, (2) a coherence function, the generated function being sufficiently averaged to provide a meaningful measure of the degree to which the two electrical signals are related to thereby indicate whether, and to what extent, sensed pressure pulsations within the flow stream are passing through at least one of the seals to the inner cavity. - View Dependent Claims (21, 22, 23)
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24. A method for use with a fluid transport system having an upstream pipe, a downstream pipe and a valve connected between the upstream pipe and the downstream pipe for controlling fluid flow through the system, the valve having at least one upstream seal, at least one downstream seal and an inner cavity effectively isolated by the seals from the fluid flow stream, the method for detecting a leak in at least one of the seals when the valve is closed, comprising the steps of:
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generating sound energy within the fluid transport system utilizing an external sound source in fluid communication with the system; sensing pressure pulsations in the system at at least one of;
(1) a predetermined distance upstream of the upstream seal and, (2) a predetermined distance downstream of the downstream seal and generating first representative electrical signals as a function of time, the pressure pulsations resulting from the acoustic energy generated by the sound source;sensing substantially simultaneous pressure pulsations within the inner cavity and generating second representative electrical signals as a function of time; and analyzing the first and second electrical signals and generating at least one of the following functions;
(1) a frequency response function and, (2) a coherence function, the generated function being sufficiently averaged to provide a meaningful measure of the degree to which the two electrical signals are related to thereby indicate whether, and to what extent, sensed pressure pulsations within the fluid transport system are passing through at least one of the seals to the inner cavity. - View Dependent Claims (25, 26, 27, 28)
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Specification