JPH07109254B2 - Check valve test system - Google Patents

Description

FIELD OF THE INVENTION The present invention relates generally to the field of testing the condition of valves, and more specifically to testing check valves.

BACKGROUND OF THE INVENTION Check valves are a type of one-way valve used in controlling fluid flow through conduits. The check valve allows the fluid to flow in one direction and prevents the fluid from flowing in the opposite direction. Check valves are generally slewing hinges (pi
It consists of a disc attached to a voting hinge). When the fluid is flowing in the direction in which it can flow, the disk is pushed upwards by the fluid to pass the fluid. When fluid is not flowing or is about to flow backwards, the disk swirls downward (usually due to gravity) and closes the conduit to prevent backflow. Typically, all parts of the check valve are installed inside the valve chamber, with no external parts that can be visually inspected.

Because it is difficult, if not impossible, to visually inspect a check valve, the danger is that the user generally does not know whether the check valve is actually working until the time it is needed. It is in. It's already too late then. The check valve is normally open on a continuous basis in most operating conditions because the pump is in steady state operation and fluid is constantly pumped in the direction that the conduit can flow. Thus, it will be appreciated that if the check valve disc or other component is broken and simply placed in the conduit, no one will know there is a problem. And when the "check" function is needed, the valve cannot function. Such unfortunate incidents occur frequently in industry. further,
A valve that is too small or too large, or any disturbed condition in the conduit, can cause damaging vibrations or "bouncing" of the check valve disc.
There is no practical way in the prior art to check for such harmful vibrations. To date, the inventors are unaware of any useful method for testing the condition of a check valve without removing the valve assembly or regurgitating the fluid.

SUMMARY OF THE INVENTION Briefly stated, the present invention tests the condition of a check valve while the check valve is fully assembled and operating under various conditions of fluid flow, including no flow. A method and apparatus therefor. The present invention includes the use of an ultrasonic transducer from which the check valve casting can be performed.
High-frequency sound waves are sent to reach the valve disc via the fluid transported via g). Sound wave reflections are detected and analyzed using signal recording and conditioning equipment to aid in determining valve disc position and movement.

It is an object of the present invention to provide a test system useful in testing and analyzing the condition of valve components without physically inspecting the check valve components or backflowing fluid.

Another object of the present invention is to provide a check valve test method and apparatus for determining whether a check valve is in a non-actuated state.

Yet another object of the present invention is to provide a check valve test method and apparatus for determining whether a check valve is still operational but is in a detrimental operating condition.

Other objects, features and advantages of the present invention will become apparent upon reading and understanding the following specification in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a check valve test system according to the present invention.

2 is a cutaway side view of the check valve being tested in accordance with the present invention of FIG. 1 and represents a portion of the check valve testing system of FIG.

FIG. 3 is a schematic view of a part of the check valve test system shown in FIG. 1, showing another embodiment.

FIG. 4 is a diagram representing various other installation points of the transducer of the check valve test system of FIG.

Detailed Description of the Preferred Embodiments The drawings are examined in more detail. Like numbers refer to like parts throughout the figures. FIG. 1 shows a check valve test system 10 of the present invention including an ultrasonic wave sending unit 12 and an ultrasonic wave receiving unit 16.
The ultrasonic wave sending unit 12 is connected to the wave sending transducer 13 by a wire 14, and the ultrasonic wave receiving unit 16 is connected by a wire.
It is connected at 17 to a wave receiving converter 18. The sending unit 12 is the first such as an oscilloscope by the signal cable 21.
Is connected to the recording device 23, and is also connected to the signal adjusting device 25 by the signal cable 21a. The wave receiving unit 16 is connected to the first recording device 23 by a signal cable 28 and is connected to the signal conditioning device 25 by a cable 28a.

The signal conditioning device 25 comprises a discriminating device 26 and a counter / delay device 27. The function of these devices is described below. The signal conditioning device 25 is connected to a first recording device by a signal cable 30 and is connected to a second recording device such as a second oscilloscope by a signal cable 31.
The signal cable 31 is an analog output terminal 34 of the signal conditioner 25.
It is connected to the.

Transducers 13 and 18 are shown operating on the check valve assembly 40 shown in detail in FIG. Check valve assembly 40 is fluid conduit 42
The fluid conduit 42 allows the fluid from the inlet 42 to the outlet 43 to flow in the normal direction in the direction of arrow A without obstructing the fluid. A valve chamber 45 accommodating a rocking disc assembly 46 is located between the inlet 42 and the outlet 43 of the fluid conduit 41. Swing disk assembly 46 is a hinge arm
It has a valve disc 48 mounted on 49, the hinge arm being pivotally connected to a pin 50 mounted on the inner wall 51 of the valve chamber. Oscillating disc assembly 46
In some embodiments, a valve disc 48 and a hinge arm are included.
Some are forged so that 49 forms one component. In another embodiment, as shown in FIG. 2, the valve disc 48 is attached to the hinge arm 49 by a stud nut 53, which stud nut 53 projects upwardly from the disc 48. It is attached to the butt nut 54. The check valve assembly 40 further includes a lower valve stop 56 and a back stop 57.

The check valve test system 10 of the present invention is installed in the field along the check valve fluid conduit system. The wave delivery unit 12 is installed to generate and transmit a pulsating ultrasonic signal. That is, the sound wave signals are repeatedly generated at desired equal intervals. The time interval between each pulse is called "pulse interval". The rate at which pulses are generated is called the “pulse rate”. The frequency of the ultrasonic waves is set high enough to ensure that the acoustic waves are transmitted through various media such as valve casting, fluids and all other materials for the valve assembly 40. The user installs the sending transducer 13 and the receiving transducer 18 in the valve assembly body to direct the sound waves towards the valve disc 48 in the valve chamber 45. The two transducers 13, 18 are arranged in relation to each other so that the sound waves from the delivery transducer 13 are guided into the valve chamber 45 and then received by the receiving unit 18. The other arrangement example of the converters 13 and 18 is the third
Shown in Figures and 4. The positions of the transducers shown in FIG. 3 and the positions of “a”, “b” and “c” in FIG. 4 are determined by the receiving transducer after the sound wave from the transmitting transducer 13 is reflected by the valve disc 48. Note that it is oriented to be received by container 18.
The position of the transducers 13, 18 represented by the "d" position in FIG.
The receiving transducer 18 is like receiving acoustic waves from the transmitting transducer 13 that are not reflected by the valve disc 48. The significance of this "d" position is explained below.

Referring again to FIG. 1, the wave delivery unit 12 produces a trigger signal each time an ultrasonic pulse is produced in the delivery transducer 13. This trigger signal is signal cable 21
Is transmitted to the first recording device 23 via. In the first recording device, this trigger signal triggers the recording device to start the recording sequence. For example, in the case of an oscilloscope, the trigger signal triggers the oscilloscope to start the sweep function. This same trigger signal is transmitted to the signal conditioning device 25 via the signal cable 21a, which trigger signal is due to the fact that the sound wave is transmitted from the transducer 13.
Trigger 25. The signal conditioner 25 must then start the adjusting function described below.

When each sound wave is generated by the sound transducer 13 and is advanced to the valve chamber 45, the wave receiving transducer 18 is connected to the valve assembly 40.
Begins to receive reflected and refracted sound waves from the components of. For example, some of the waves generated by the delivery transducer 13 are reflected and refracted by the metal casting of the valve assembly 40, some of the waves are reflected and refracted by the fluid in the valve chamber 45, and some are reflected. Reflected by the valve disc 48. Various other materials and components within valve assembly 40 and valve chamber 45 may also reflect and refract portions of the respective waves produced by delivery transducer 13. In this way, one wave (pulse) is generated by the transmission converter 13.
The receiving transducer 18 receives a plurality of sound waves for each occurrence of. The waves received by the receiving transducer 18, whether reflected or refracted,
In the present disclosure, it is referred to as “reflected wave”. Each time each reflected wave is received by the receiving transducer 18, the wave receiving unit 16 recognizes the reception of the wave and produces a signal. The signal is sent to the first recording device 23 via the signal cable 28 and recorded. In the oscilloscope example, 1
Each signal corresponding to the individual received reflected waves is recorded in the form of a spike waveform. Since each of the reflected waves is received by the receiving unit 18 at different times, a series of temporally separated signals is sent by the receiving unit 16 to the oscilloscope 23. Therefore, a series of signals appear as multiple spike waveforms across the oscilloscope screen. The amplitude of the spike waveform corresponds to the energy of the individual reflected waves received by the receiving transducer 18. An example of such a sweep is provided by trace "f" in FIG.

The pulse rate of the delivery unit 12 is adjusted by the user to help in receiving a good sweep trace on the oscilloscope 23. That is, the pulse rate is set so that the equal number of reflected waves resulting from the first generated sound wave are received by the receiving unit 18 before the next generated wave is sent to the sending transducer 13. Each time a new wave is generated in the sending converter 13, a trigger signal is sent from the sending unit to the oscilloscope via the signal cable 21 and triggers the oscilloscope to start a new sweep. As mentioned above, during a new sweep, the oscilloscope will
The input from 16 is recorded, which corresponds to the received reflected waves associated with the individual generated sound wave pulses. By analyzing the traces recorded with each sweep, the user becomes familiar with the spike waveform corresponding to "noise" 60. "Noise" 60 corresponds to waves that are reflected and refracted by valve castings, fluids, or various other materials. The user also has a special target spike (pa) corresponding to the part of the wave reflected on the valve disc 48.
rticular target spike) 61. The pulse rate of the sending unit 12 is adjusted so that the target spike 61 is clearly and surely generated at each sweep of the oscilloscope 23.

At the same time that a series of signals is sent from the receiving unit to the oscilloscope 23, the same series of signals will be sent to the signal cable 28a.
Is transmitted to the signal conditioning device via. Signal conditioner 25
Includes (1) separating the target spike 51 for each signal sweep of the first recording device 23, and (2) the digital signal in connection with each sweep of the first recording device 23.
It serves the two main functions of converting to an analog signal which is transmitted via 31 to the second recording device 33. The separation function is fulfilled as follows. That is, the trigger signal is sent to the cable 21 every time the sending unit 12 generates a pulse.
It is transmitted to the counter / delay device 27 of the signal conditioning device 25 via a. Counter / delay device by this trigger signal
The 27 counters are reset to "zero" to begin counting relative time after each pulse is sent by the sending unit 12. The delay mechanism of the counter / delay device 27 affects the counter by delaying the start time of counting by a user-selected amount of increasing time. In this way, the user adjusts the delay so that the counter does not start counting until most, if not all, of the reflected waves that eventually result in "noise" 60. The signal conditioning device 25 is a discrimination device 26.
Is also equipped. The function of the discriminator 26 is to control the signal conditioner 25 to recognize only signals from the receiving unit 16 having an amplitude greater than the selected minimum amplitude. Therefore, in practice, the user is
The discriminator 26 is adjusted so that 25 prefers to identify signals of some high amplitude. Therefore, it is understood that by selectively adjusting the delay device 27 and the discriminator device 26, the user can effectively isolate the target spike 61 from all of the noise spikes 60. The signal conditioner differentially seeks a signal that occurs after the delay period and that has an amplitude greater than or equal to the minimum discriminative amplitude during each pulse interval. The separated signal is transmitted to the first recording device 23 via the signal cable 30 and recorded therein. If an oscilloscope is used, the separated signal is displayed on the lower trace "g" during each sweep of the oscilloscope.

When performing the second function, the counter of the counter / delay device 27 starts counting as soon as the delay period ends,
The signal conditioning device 25 receives a signal having an amplitude larger than the discrimination amplitude (that is, a target spike) and receives the signal.
Continue counting until you receive it from 16. When the counter stops counting, the digital output from this digital counter is input to the digital / analog converter in the signal conditioning device 25. The output of this D / A converter is analog output terminal 3
It is transmitted to the second recording device 33 through 4. The output of the D / A converter is preferably in the form of an equivalent voltage so that a low count number in the counter is converted into a low voltage and a high count number in the counter is converted into a high voltage. The counter is reset by a trigger signal from the wave delivery unit 12 each time a new wave pulse is generated by the delivery converter. Therefore, each time a new wave is generated, the counter newly starts counting and separate analog signals are generated at each pulse interval. The counter sends a sound wave of a predetermined pulse from the transducer 13 to the valve disc.
It is understood that it counts the relative length of time from reaching 48 to the receiving transducer 18 ("critical distance")) critical distance)). If it takes a long time for a wave to travel this critical distance, the count of the digital counter will increase and the voltage of the analog output will increase. On the contrary, if it takes a relatively short time for the wave to travel the critical distance, the count value of the digital counter becomes small and the voltage of the analog output becomes low. Since the time it takes for a sound wave to travel a critical distance is directly related to the distance the valve disk 48 is from the transducers 13,18, the output voltage is the valve disk in the valve chamber 45.
Relative to 48 positions.

The voltage of the analog output is sent to the second recording device 33 via the cable 31, and the second recording device 33 collects and records the voltages corresponding to the individual pulse intervals of the sending unit 12. Preferably, the second recording device 33 performs one or more of the functions of collecting, storing, correlating, recording and analyzing the output of the signal conditioner.

In the preferred embodiment, the second recording device 33 is a storage oscilloscope, in which the voltage corresponding to successive pulse intervals of the delivery unit 12 is converted into a digital number and stored. To be done. The storage oscilloscope 33 also functions to plot the collected data continuously over time, generating and displaying a time (distance) versus real-time curve. This temporal correlation of the collected data can be used to diagnose the condition and function of the check valve. By way of example with reference to FIG. 1, two typical traces are represented as the output of the second recorder 33. In each trace, the vertical axis represents the "relative time", which is a factor directly related to the distance (voltage) between the valve disk 48 and the transducers 13,18. . This parameter is related to the individual pulse intervals of the delivery unit and more specifically to the relative time the counter counts for each pulse interval of the delivery unit 12, thus It is called. The horizontal axis of each trace represents real time. This parameter is called “real time” because it is not reset every pulse interval of the sending unit 12 but is a continuous time that collectively covers a plurality of pulse intervals.

In another embodiment of the invention, the recording device is a computer or a combination of an oscilloscope and a computer, in which the computer performs various operations on the analog output of the signal conditioning device 25. The computer performs spectral (frequency) analysis of voltage / time traces. Further, the computer uses known mathematical formulas and additional inputs such as known speeds at which sound travels through various materials to determine the position of the valve disk 48 within the valve chamber 45 at any "real time" time point. Also calculated in. In yet another embodiment, the second recording device 33 includes a measurement analog tape recorder (instrumentation) for collecting, recording, and storing analog signals.
analog tape recorder). The stored data is then passed from this tape recorder to an oscilloscope for display and analysis, or to a computer for further analysis.

An example of analysis of the traces "h" and "i" drawn by the second oscilloscope 33 is shown here. Trace "h" is a typical trace representing valve disc position and position variation with fluid flowing. Throughout the real time, relative time and disk 48 and transducer 13,1
It is understood that the voltage associated with the distance between 8 and 8 varies from higher voltage to lower voltage. This indicates that the distance between the valve disc 48 and the transducers 13, 18 is different for each pulse of the sound wave. Therefore, the trace “h” represents the vibration or “bounce” of the valve disc 48. This condition represents an improper valve size or some other harmful condition that will cause the valve to fail in the future. The trace "i" shows the voltage increasing gradually from the open position of the valve disk 48 (low voltage = short relative time = short distance from the transducer). It shows a state of gradually moving to a closed position (high voltage = long relative time = long distance from the converter). Analyzing a trace, such as trace "i", determines whether the valve disk 48 is free moving or stuck at one point during rocking, and whether the valve moves completely from the open position to the closed position. , As well as help determine if the disk is stable under various conditions of normal fluid flow. First recording device
Analyzing the output of 23 shows whether the valve disk 48 is actually in place (ie not broken (broken
off) or still in place), the relative position of the valve disc 48 and the ability of the oscillating disc assembly 46 to swing sufficiently from the open position to the closed position are immediately determined. Useful when

A user can use the system of the present invention to test valve conditions at various flow conditions. For example, the check valve assembly 40 first
Is tested under full fluid flow. An analysis of the records taken during this first test will show whether the valve is (or appears to be) open.
And to determine if the valve disc is free from vibration or wobbling in full flow conditions.
The test is then carried out using fluid streams of various flow rates, which are lower than the full flow rate. As a result of this second test, the user is able to record and analyze the position of the valve disc 48 at various flow velocities, and the effects on the vibration and sway of the valve disc 48 when the flow velocity is reduced. It can be recorded and analyzed. Finally, the user turns off the fluid flow through each fluid conduit 41, identifies the position of the valve disc 48 during the test, and records and analyzes the oscillating characteristics (ie, whether it does not move) of the oscillating disc assembly 46. be able to.

In another embodiment of the invention, the converters 12, 13 are the fourth
It is installed at the position indicated by "d" in the figure. With the transducers 13, 18 in this position, the user wants to check whether the valve disc 48 has taken the fully closed position.
Therefore, if the valve disc 48 is not completely closed,
The sound waves generated by the emitting transducer 13d are (mostly) received by the receiving transducer 18d. However, the valve disc 48
When fully seated, the valve disk 48 will interfere with the sound waves produced by the delivery transducer 13d so that no or only a small portion will be received by the receiving transducer 18d.

While described in detail in relation to each of its preferred embodiments of the invention, alterations and modifications are made within the spirit and scope of the invention as described above and as set forth in the appended claims. It will be understood that is possible.

 ─────────────────────────────────────────────────── --Continued front page (56) References JP-A-56-147978 (JP, A) JP-A-56-89072 (JP, A) US Pat. No. 4543649 (US, A)

Claims (14)

[Claims] 1. A method for testing the operating condition of a fluid flow check valve comprising a movable valve disc provided in a valve chamber defined by valve casting, wherein a sound wave sending unit and a sound wave receiving unit are arranged on the check valve. The step of setting the sound wave toward the valve casting and passing through the valve casting toward the check valve disc; the step of receiving the reflected sound wave reflected by the valve disk, the step of advancing the sound wave to the receipt of the reflected sound wave A step of observing the passage of time between; including a step of determining the position of the check valve in the valve chamber according to the observed passage of time, whereby the position of the valve disc is determined. 2. A step of observing time, the step of emitting a first signal in advancing a sound wave, the step of transmitting a first signal to a recording device, and the step of receiving a first signal and then increasing a predetermined amount. When a time elapses, a step of starting relative time in the recording apparatus, a step of emitting a second signal when receiving a reflected sound wave, a step of transmitting a second signal to the recording apparatus, a step of receiving the second signal in the recording apparatus A method according to claim 1 including the steps of terminating the relative time in, and recording the passage of time from the start to the end of the relative time. 3. The method according to claim 1, wherein the step of disposing the sound wave sending unit and the sound wave recording unit on the check valve includes the step of disposing the sound sending unit and the recording unit at the same position on the check valve. The method described. 4. A method for testing the operating condition of a fluid flow check valve comprising a movable valve disc provided in a valve chamber defined by valve casting, wherein a first sound wave is directed toward the valve casting and the valve Record the time lapse between advancing and receiving the first sound wave, passing through the casting and advancing toward the valve disk, receiving the reflected sound wave generated when the first sound wave is reflected by the valve disk. Advancing the second sound wave toward the valve casting and passing through the valve casting toward the valve disc; receiving a reflected sound wave generated by reflecting the second sound wave on the valve disc; Steps to record the passage of time between proceeding and receiving Compare the passage of time from the advance of the first sound wave to the reception of the second passage of sound and the passage of the time from the advance of the second sound wave to the receipt of the second sound wave. A method comprising the step of determining a relative change in the position of the valve disc during advancement. 5. The method of claim 4 further comprising the step of sequentially repeating each of the above steps for a period of time to produce a comparison from a plurality of advanced sound waves. 6. A method of testing the working condition of a fluid flow check valve comprising a movable valve disc provided in a valve chamber defined by valve casting, the sound wave being directed to and passing through the valve casting. Then, the step of advancing toward the valve chamber, the step of receiving a plurality of reflected sound waves obtained by reflecting the advanced sound wave on the valve component, and the plurality of reflected sound waves being received, the reflected sound wave reflected on the valve disc is received. Generating the corresponding separated signal, determining the time elapsed between the selected start time of the relative time and the generation of the separated signal, each of the above steps being at selected intervals Steps that repeat during a real-time period and A time-dependent correlation of the elapsed time defined for the system, whereby the elapsed time corresponds to the relative position of the valve disc in the valve chamber and thus the movement of the valve can be determined and analyzed. The method of including. 7. A method for testing the operating state of a fluid flow check valve having a movable valve disc provided in a valve chamber, the method comprising: advancing a sound wave toward the valve chamber; A step of receiving a plurality of reflected sound waves obtained by reflecting on a part, and a step of generating a separated signal corresponding to the reflected sound waves reflected on the valve disc when the plurality of reflected sound waves are received. And then starting relative time to the selected increase time to avoid generation of a signal from the reflected sound wave that occurs before the selected increase time elapses, and below a predetermined minimum level. A step that includes the step of differentially suppressing the generation of a signal from a reflected sound wave having an energy level, a selected start time of the relative time The step of determining the elapsed time between the generation of the separated signal and the step of determining the elapsed time between the start of the relative time and the generation of the separated signal. The steps are repeated at a selected interval for a certain real-time period, and during each step, a time-wise inter-relationship of the elapsed time is generated, whereby the elapsed time is reduced by the valve. A method comprising the step of corresponding to the relative position of the valve disc in the chamber, so that the movement of the valve can be determined and analyzed. 8. The method of claim 6 further comprising the step of analyzing elapsed time against a real-time trace. 9. A method of testing the working condition of a fluid flow check valve comprising a movable valve disc provided in a valve chamber defined by valve casting, the sound wave being directed to and passing through the valve casting. In response to whether the sound wave is received or not received, the sound wave receiving unit is positioned to receive the advanced sound wave, the sound wave reception is recorded, and the sound wave is received or not received. A method comprising the step of determining the position of a disc within a valve chamber. 10. A step of obtaining an elapsed time, a step of generating a first signal when advancing a sound wave, a step of transmitting the first signal to a recording device, and an increasing time selected after receiving the first signal. The step of initiating relative time in the recording device after the passage of time, the step of generating a second signal when receiving the separated signal, the step of transmitting the second signal to the recording device, the recording when receiving the second signal 7. A method according to claim 6 including the steps of terminating the relative time in the device and recording the time from the start to the end of the relative time. 11. The method according to claim 1, wherein the step of disposing the sound wave sending unit and the sound wave receiving unit includes the step of dismounting the sound wave sending unit and the sound wave receiving unit and temporarily disposing the check valve. The method described in. 12. The method of claim 4, further comprising the step of removably and temporarily disposing the sound wave sending unit and the sound wave receiving unit on the check valve. 13. The method according to claim 6, further comprising the step of removably and temporarily disposing the sound wave sending unit and the sound wave receiving unit on the check valve. 14. The method according to claim 9, further comprising the step of removably and temporarily disposing the sound wave sending unit and the sound wave receiving unit on the check valve.