US4102175A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Response time verification of in situ hydraulic pressure sensors in a nuclear reactor
Assignee: Electric Power Research Institute
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Filing: 1976-10-15
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Granted: 1978-07-25
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Expires: 1996-10-15
Abstract
Abstract Method and apparatus for verifying response time in situ of hydraulic pressure and pressure differential sensing instrumentation in a nuclear fluid circuit is disclosed. Hydraulic pressure at a reference sensor and at an in situ process sensor under test is varied according to a linear ramp. Sensor response time is then determined by comparison of the sensor electrical analog output signals. The process sensor is subjected to a relatively slowly changing and a relatively rapidly changing hydraulic pressure ramp signal to determine an upper bound for process sensor response time over the range of all pressure transients to which the sensor is required to respond. Signal linearity is independent of the volumetric displacement of the process sensor. The hydraulic signal generator includes a first pressurizable gas reservoir, a second pressurizable liquid and gas reservoir, a gate for rapidly opening a gas communication path between the two reservoirs, a throttle valve for regulating rate of gas pressure equalization between the two reservoirs, and hydraulic conduit means for simultaneously communicating a ramp of hydraulic pressure change between the liquid/gas reservoir and both a reference and a process sensor. By maintaining a sufficient pressure differential between the reservoirs and by maintaining a sufficient ratio of gas to liquid in the liquid/gas reservoir, excellent linearity and minimal transient effects can be achieved for all pressure ranges, magnitudes, and rates of change of interest.
Inventors
- 👤 Carlton G. Foster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:03
CPC Classifications
G; G01; G01L; G01L27/00; G01L27/002; G01L27/005
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
121 words
A hydraulic signal generator for use in in situ verification of the response time of a hydraulic process sensor comprising a first reservoir for containing a gas under pressure; a second reservoir for containing a gas and a liquid under pressure; conduit means connecting said first and second reservoirs for communicating gas between said first and second reservoirs; means in said conduit means intermediate of said reservoirs for gating said conduit means; throttle means in said conduit means intermediate of said reservoirs for providing substantially linear pneumatic pressure equalization in the pressure ranges of interest between said reservoirs; and non expansible outlet means coupled to said second reservoir for providing hydraulic fluid communication between said second reservoir and said process sensor.
Claim 2
Dependent Claim
121 words
A hydraulic signal generator for use in in situ verification of the response time of a hydraulic process sensor comprising a first reservoir for containing a gas under pressure; a second reservoir for containing a gas and a liquid under pressure; conduit means connecting said first and second reservoirs for communicating gas between said first and second reservoirs; means in said conduit means intermediate of said reservoirs for gating said conduit means; throttle means in said conduit means intermediate of said reservoirs for providing substantially linear pneumatic pressure equalization in the pressure ranges of interest between said reservoirs; and non expansible outlet means coupled to said second reservoir for providing hydraulic fluid communication between said second reservoir and said process sensor.
Claim 3
Dependent Claim
42 words
A hydraulic signal generator according to claim 1, wherein said throttle means comprises a valve disposed between said gating means and said second reservoir, for inhibiting fluid turbulence in said conduit means and in said second reservoir caused by said gating means.
Claim 4
Dependent Claim
57 words
A hydraulic signal generator according to claim 2, wherein the gas volume capacity of said first reservoir is large in relation to the gas volume capacity of said second reservoir and the volumetric displacement capacity of said process sensor, such that said generator is operative as a constant pressure driving source over the pressure range of interest.
Claim 5
Dependent Claim
187 words
A hydraulic signal generator for use in in situ verification of the response time of a hydraulic process sensor comprising: a first reservoir for containing a gas under pressure; a second reservoir for containing a gas and a liquid under pressure; conduit means connecting said first and second reservoirs for communicating gas between said first and second reservoirs; means in said conduit means intermediate of said first and second reservoirs for gating said conduit means; throttle means in said conduit means intermediate of said reservoirs for providing substantially linear pneumatic pressure equalization between said reservoirs in pressure ranges of interest; outlet means coupled to said second reservoir for providing hydraulic fluid communication between said second reservoir and said process sensor; and a reference sensor coupled to said second reservoir for providing a reference signal for comparison with an output signal of said process sensor, said generator being of sufficient hydraulic fluid volume relative to the process sensor and to said reference sensor to be capable of generating signals whose waveform and rate of change are essentially independent of the volumetric displacement of the process and reference sensors.
Claim 6
Dependent Claim
187 words
A hydraulic signal generator for use in in situ verification of the response time of a hydraulic process sensor comprising: a first reservoir for containing a gas under pressure; a second reservoir for containing a gas and a liquid under pressure; conduit means connecting said first and second reservoirs for communicating gas between said first and second reservoirs; means in said conduit means intermediate of said first and second reservoirs for gating said conduit means; throttle means in said conduit means intermediate of said reservoirs for providing substantially linear pneumatic pressure equalization between said reservoirs in pressure ranges of interest; outlet means coupled to said second reservoir for providing hydraulic fluid communication between said second reservoir and said process sensor; and a reference sensor coupled to said second reservoir for providing a reference signal for comparison with an output signal of said process sensor, said generator being of sufficient hydraulic fluid volume relative to the process sensor and to said reference sensor to be capable of generating signals whose waveform and rate of change are essentially independent of the volumetric displacement of the process and reference sensors.
Claim 7
Dependent Claim
183 words
A hydraulic signal generator for use in in situ verification in response time of a hydraulic process sensor under test comprising a first accumulator for containing a gas under pressure; a second accumulator for containing a gas and liquid under pressure and having an outlet coupled to said process sensor for supplying hydraulic fluid thereto, said first and second accumulators each having a volume substantially greater than the total volumetric displacement of said process sensor; a non-expansible conduit coupled between said accumulators for communicating gas between said accumulators; a solenoid valve disposed in said conduit between said accumulators for opening and closing a pneumatic communication path between said accumulators; an adjustable throttle valve disposed in said conduit between said solenoid valve and said second accumulator for equalizing pneumatic pressure between said accumulators at a constant rate over the pressure range of interest and for isolating solenoid valve-induced fluid turbulence from said second accumulator; and a non-expansible hydraulic fluid conduit coupled to a hydraulic fluid outlet of said second accumulator for communicating hydraulic fluid between said second accumulator and said process sensor under test.
Claim 8
Dependent Claim
183 words
A hydraulic signal generator for use in in situ verification in response time of a hydraulic process sensor under test comprising a first accumulator for containing a gas under pressure; a second accumulator for containing a gas and liquid under pressure and having an outlet coupled to said process sensor for supplying hydraulic fluid thereto, said first and second accumulators each having a volume substantially greater than the total volumetric displacement of said process sensor; a non-expansible conduit coupled between said accumulators for communicating gas between said accumulators; a solenoid valve disposed in said conduit between said accumulators for opening and closing a pneumatic communication path between said accumulators; an adjustable throttle valve disposed in said conduit between said solenoid valve and said second accumulator for equalizing pneumatic pressure between said accumulators at a constant rate over the pressure range of interest and for isolating solenoid valve-induced fluid turbulence from said second accumulator; and a non-expansible hydraulic fluid conduit coupled to a hydraulic fluid outlet of said second accumulator for communicating hydraulic fluid between said second accumulator and said process sensor under test.
Claim 9
Dependent Claim
36 words
Apparatus according to claim 5, further including a reference sensor and a non-expansible conduit coupled between said reference sensor and said second accumulator outlet for communicating hydraulic fluid between said reference sensor and said second accumulator.
Claim 10
Dependent Claim
42 words
Apparatus according to claim 6, further including means for pneumatically pressurizing the first accumulator and means for pneumatically pressurizing the second accumulator to a pressure differing from said first accumulator by a sufficient amount to ensure adequate linearity of the hydraulic waveform.
Claim 11
Dependent Claim
33 words
Apparatus according to claim 6, further including means for establishing the pressurized pneumatic volume of the second accumulator substantially greater than the combined volumetric displacement of said process sensor and said reference sensor.
Claim 12
Dependent Claim
21 words
Apparatus according to claim 8, wherein said accumulators are mounted rigidly with respect to one another for preventing relative oscillation therebetween.
Claim 13
Dependent Claim
41 words
Apparatus according to claim 6, wherein said reference sensor is a variable reluctance sensor including a magnetically sensitive transducer element and wherein said reference sensor is mounted with the magnetically sensitive element orthogonal to magnetic fields emanating from said solenoid valve.
Claim 14
Dependent Claim
35 words
Apparatus according to claim 5, wherein said throttle valve is located in said conduit between said gate valve and said second accumulator for inhibiting gate-valve induced turbulence in said conduit and in said second reservoir.
Claim 15
Independent Claim
207 words
A method for generating a linear ramp hydraulic signal with a first pressurizable reservoir, a second pressurizable reservoir, a fluid conduit connecting said reservoir, a gate valve in said conduit for opening fluid communication between said reservoirs, a throttle valve in said conduit for regulating the rate of pressure equalization between said reservoirs and an outlet in said second reservoir for communicating hydraulic fluid pressure to a hydraulic pressure sensing device having substantially smaller volumetric displacement than the volume of said reservoirs to compare the response time of a hydraulic process sensor in situ in a nuclear reactor with the response time of a reference sensor, said method comprising the steps of: pressurizing said first reservoir with a gas; pressurizing said second reservoir with a gas and a liquid pressure substantially different from the pressure in said first reservoir, communicating hydraulic fluid under pressure between said sensors and said second reservoir; thereafter rapidly opening said conduit to establish a pneumatic communication path between said first and second reservoirs; while regulating, through said throttle valve, the pneumatic pressure equalization between the first and second reservoirs at an essentially constant rate over the pressure range of interest to generate a linear ramp change in hydraulic pressure at the sensors.
Claim 16
Independent Claim
207 words
A method for generating a linear ramp hydraulic signal with a first pressurizable reservoir, a second pressurizable reservoir, a fluid conduit connecting said reservoir, a gate valve in said conduit for opening fluid communication between said reservoirs, a throttle valve in said conduit for regulating the rate of pressure equalization between said reservoirs and an outlet in said second reservoir for communicating hydraulic fluid pressure to a hydraulic pressure sensing device having substantially smaller volumetric displacement than the volume of said reservoirs to compare the response time of a hydraulic process sensor in situ in a nuclear reactor with the response time of a reference sensor, said method comprising the steps of: pressurizing said first reservoir with a gas; pressurizing said second reservoir with a gas and a liquid pressure substantially different from the pressure in said first reservoir, communicating hydraulic fluid under pressure between said sensors and said second reservoir; thereafter rapidly opening said conduit to establish a pneumatic communication path between said first and second reservoirs; while regulating, through said throttle valve, the pneumatic pressure equalization between the first and second reservoirs at an essentially constant rate over the pressure range of interest to generate a linear ramp change in hydraulic pressure at the sensors.
Claim 17
Dependent Claim
28 words
A method according to claim 12, further including establishing the pneumatic pressure in said first reservoir at a pressure sufficient to ensure adequate linearity of the hydraulic signal.
Claim 18
Dependent Claim
69 words
A method according to claim 13, further comprising the steps of obtaining an electrical output signal from the reference sensor representative of response to the applied bydraulic pressure ramp signal, obtaining an electrical output signal from the process sensor representative of response to the applied hydraulic pressure signal, and comparing the respective output signals, whereby the time difference therebetween is determined for verifying response time of the process sensor.
Claim 19
Dependent Claim
27 words
A method according to claim 14, further including the steps of at least temporarily storing the reference sensor response and the process sensor response for comparison therebetween.
Claim 20
Dependent Claim
44 words
A method according to claim 12, wherein said regulating step further includes the step of inhibiting gate-valve induced fluid turbulence in said conduit and in said second reservoir by locating said throttle valve in said conduit between said gate valve and said second accumulator.
Claim 21
Independent Claim
309 words
A method for testing the response time of a hydraulic process sensor in a nuclear reactor hydraulic fluid circuit comprising: hydraulically isolating said process sensor in situ; pressurizing a first reservoir containing a gas; pressurizing a second reservoir containing a gas and a liquid to a pressure sufficient to ensure adequate linearity of the hydraulic signal, said second reservoir being coupled to said first reservoir by a gated conduit; opening hydraulic communication between said second reservoir and the process sensor and between the second reservoir and a reference sensor; setting a throttle valve in said conduit between said first and second reservoirs for a first essentially constant pneumatic equalization rate over the pressure range of interest; thereafter rapidly opening said gated conduit to establish a pneumatic communication path between said reservoirs while regulating the rate of pressure equalization with said valve at said first essentially constant equalization rate over the pressure range of interest to effect a first linear ramp change in hydraulic pressure at the sensors; sensing and recording the response of said sensors to compare the time delay therebetween at said rate of said first ramp change; again pressurizing said first reservoir containing a gas; again pressurizing said second reservoir containing a gas and a liquid to a pressure sufficient to ensure adequate linearity of the hydraulic signal, setting said throttle valve for a second substantially different constant pneumatic pressure equalization rate; thereafter rapidly opening said gated conduit to establish a pneumatic communication path between said reservoirs while regulating the rate of gas pressure equalization at said second equalization rate to effect a second linear ramp change in hydraulic pressure at the sensors; and sensing and recording the response of said sensors to compare the time delay therebetween at a second ramp rate, thereby to establish the time delay characteristics of the hydraulic process sensor under test.
Claim 22
Independent Claim
309 words
A method for testing the response time of a hydraulic process sensor in a nuclear reactor hydraulic fluid circuit comprising: hydraulically isolating said process sensor in situ; pressurizing a first reservoir containing a gas; pressurizing a second reservoir containing a gas and a liquid to a pressure sufficient to ensure adequate linearity of the hydraulic signal, said second reservoir being coupled to said first reservoir by a gated conduit; opening hydraulic communication between said second reservoir and the process sensor and between the second reservoir and a reference sensor; setting a throttle valve in said conduit between said first and second reservoirs for a first essentially constant pneumatic equalization rate over the pressure range of interest; thereafter rapidly opening said gated conduit to establish a pneumatic communication path between said reservoirs while regulating the rate of pressure equalization with said valve at said first essentially constant equalization rate over the pressure range of interest to effect a first linear ramp change in hydraulic pressure at the sensors; sensing and recording the response of said sensors to compare the time delay therebetween at said rate of said first ramp change; again pressurizing said first reservoir containing a gas; again pressurizing said second reservoir containing a gas and a liquid to a pressure sufficient to ensure adequate linearity of the hydraulic signal, setting said throttle valve for a second substantially different constant pneumatic pressure equalization rate; thereafter rapidly opening said gated conduit to establish a pneumatic communication path between said reservoirs while regulating the rate of gas pressure equalization at said second equalization rate to effect a second linear ramp change in hydraulic pressure at the sensors; and sensing and recording the response of said sensors to compare the time delay therebetween at a second ramp rate, thereby to establish the time delay characteristics of the hydraulic process sensor under test.
Claim 23
Dependent Claim
178 words
A hydraulic signal generator for use in in situ verification of response time of a hydraulic process sensor under test comprising: a first accumulator for containing a gas under pressure; a second accumulator for containing a gas and liquid under pressure and having an outlet coupled to said process sensor for supplying hydraulic fluid thereto, said first and second accumulators each having a volume substantially greater than the total volumetric displacement of said process sensor; a conduit coupled between said accumulators for communicating gas between said accumulators; an externally actuable valve disposed in said conduit between said accumulators for opening and closing a pneumatic communication path between said accumulators; an adjustable throttle valve disposed in said conduit between said externally actuable valve and said second accumulator for equalizing pneumatic pressure between said accumulators at a constant rate over a pressure range of interest and for isolating fluid turbulence; and a non-expansible hydraulic fluid conduit coupled to a hydraulic fluid outlet of said second accumulator for communicating hydraulic fluid between said second accumulator and said process sensor under test.
Claim 24
Dependent Claim
178 words
A hydraulic signal generator for use in in situ verification of response time of a hydraulic process sensor under test comprising: a first accumulator for containing a gas under pressure; a second accumulator for containing a gas and liquid under pressure and having an outlet coupled to said process sensor for supplying hydraulic fluid thereto, said first and second accumulators each having a volume substantially greater than the total volumetric displacement of said process sensor; a conduit coupled between said accumulators for communicating gas between said accumulators; an externally actuable valve disposed in said conduit between said accumulators for opening and closing a pneumatic communication path between said accumulators; an adjustable throttle valve disposed in said conduit between said externally actuable valve and said second accumulator for equalizing pneumatic pressure between said accumulators at a constant rate over a pressure range of interest and for isolating fluid turbulence; and a non-expansible hydraulic fluid conduit coupled to a hydraulic fluid outlet of said second accumulator for communicating hydraulic fluid between said second accumulator and said process sensor under test.
References Cited (Backward Citations)
US3159995A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-24 | 1982-01-23 | 1982-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-24 | 1986-01-23 | 1986-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-24 | 1990-01-23 | 1990-07-25 | $7700.00 | Window Closed / Lapsed |