USRE33649E - Butterfly valve having a function for measuring a flow rate and method of measuring a flow rate with a butterfly valve - Google Patents

Butterfly valve having a function for measuring a flow rate and method of measuring a flow rate with a butterfly valve Download PDF

Info

Publication number
USRE33649E
USRE33649E US07/594,866 US59486690A USRE33649E US RE33649 E USRE33649 E US RE33649E US 59486690 A US59486690 A US 59486690A US RE33649 E USRE33649 E US RE33649E
Authority
US
United States
Prior art keywords
valve
flow rate
butterfly valve
butterfly
opening
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US07/594,866
Other languages
English (en)
Inventor
Kouzi Kawai
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tomoe Technical Research Co Ltd
Original Assignee
Tomoe Technical Research Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tomoe Technical Research Co Ltd filed Critical Tomoe Technical Research Co Ltd
Application granted granted Critical
Publication of USRE33649E publication Critical patent/USRE33649E/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
    • G01F1/10—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects using rotating vanes with axial admission
    • G01F1/115—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects using rotating vanes with axial admission with magnetic or electromagnetic coupling to the indicating device
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
    • G01F1/20—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow
    • G01F1/22—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow by variable-area meters, e.g. rotameters
    • G01F1/26—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow by variable-area meters, e.g. rotameters of the valve type
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
    • G01F1/20—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow
    • G01F1/28—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow by drag-force, e.g. vane type or impact flowmeter
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D7/00—Control of flow
    • G05D7/06—Control of flow characterised by the use of electric means
    • G05D7/0617—Control of flow characterised by the use of electric means specially adapted for fluid materials
    • G05D7/0629—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means
    • G05D7/0635—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means by action on throttling means
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/7722—Line condition change responsive valves
    • Y10T137/7758—Pilot or servo controlled
    • Y10T137/7759—Responsive to change in rate of fluid flow
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8158—With indicator, register, recorder, alarm or inspection means
    • Y10T137/8225—Position or extent of motion indicator
    • Y10T137/8242—Electrical

Definitions

  • a butterfly valve has a valve member which is rotatably mounted in a main body and fixed to a valve shaft which is fixed rotatably to the main body.
  • the valve shaft is operated from outside of the main body manually or by means of a pneumatic or electric actuator so as to rotate the valve member, thus changing the valve opening.
  • the flow rate of a fluid flowing through such a butterfly valve can be controlled by measuring the flow rate by a measuring means and changing the valve opening based on the measured flow rate.
  • Such a measurement of the flow rate is conducted by, for example, a flowmeter which is independent from the butterfly valve and installed in the vicinity of the butterfly valve.
  • the flow rate measured by this flowmeter is regarded as the flow rate of the fluid flowing through the butterfly valve.
  • a typical flowmeter used for this purpose is a differential pressure type flowmeter comprises an orifice provided in the pipe in which the butterfly valve is installed, and a pressure sensor capable of detecting the differential pressure across the orifice, i.e., between the upstream and downstream sides of the orifice.
  • the flow rate is determined from the detected pressure ⁇ P and a capacity coefficient, (Cv value) which is a constant value peculiar to the orifice and determined beforehand through, for example, an experiment.
  • such a combination system comprises a pressure sensor capable of detecting the differential pressure of the fluid across the butterfly valve and means for detecting the valve opening of the butterfly valve.
  • a capacity coefficient (Cv value) as function of the valve opening peculiar to this butterfly valve is beforehand determined through, for example, an experiment.
  • the flow rate is determined from the detected differential pressure ⁇ P and the value of the capacity coefficient Cv corresponding to the detected valve opening.
  • Another combination system similar to the above-mentioned combination system of a butterfly valve and a pressure sensor is disclosed in Japanese Utility Model Unexamined Publication No. 62-1117, which is designed to measure the flow rate of a fluid flowing through a gate valve used also as such an orifice.
  • this combination system comprises a pressure sensor capable of detecting the differential pressure across the gate valve, and means for detecting the valve lift of the gate valve.
  • a capacity coefficient (Cv value) as a function of the valve lift peculiar to this gate valve is beforehand determined through, for example, an experiment.
  • the flow rate is determined by the detected differential pressure ⁇ P and the value of the capacity coefficient Cv corresponding to the detected valve lift.
  • Flowmeters of types other than the above mentioned differential pressure type also has been used.
  • a system has been known in which the valve opening of a butterfly valve disposed in a line of a conductive fluid is controlled in accordance with the flow rate of the fluid measured by an electromagnetic flowmeter disposed independently in the vicinity of the butterfly valve.
  • a butterfly valve system including such means for measuring the flow rate therefore complicates the construction of the flow passage, failing to meet the demand for a compact design.
  • a first object of the present invention is to provide a butterfly valve in which the valve member and the valve shaft function as a sensor for measuring the flow rate.
  • a second object of the present invention is to provide a method of measuring flow rate of a fluid flowing through a butterfly valve, wherein the valve member and the valve shaft of the butterfly valve function as a sensor.
  • the first object of the present invention can be achieved by a butterfly valve having a function for measuringf a flow rate of a fluid flowing through said butterfly valve, comprising;
  • the flow rate of a fluid flowing through a butterfly valve is ruled by the differential pressure across the butterfly valve, i.e., between the upstream and downstream sides of the butterfly valve, and the characteristic which is peculiar to the butterfly valve, provided that the type of the fluid and the flowing conditions are unchanged.
  • the flow rate Q can be expressed as the following formula (1) as a function F of variants ⁇ (valve opening) and ⁇ P (differential pressure).
  • valve opening ⁇ and the Cu value (practical torque coefficient) which is a function of variances T (dynamic torque) and ⁇ P (differential pressure).
  • the Cv value and the Cu value are respectively expressed by a function f of variants Q and ⁇ P, and a function g of vaiants T and ⁇ P as shown in the following formulae (3) and (4).
  • the butterfly valve of the present invention has a flow rate computation means for computing the flow rate of a fluid as a predetermined function of the valve opening and the dynamic torque.
  • a flow rate computation means can automatically output the computed flow rate.
  • the torque detection means used in the butterfly valve of the present invention preferably includes a strain detector provided to the valve shaft, and more preferably such a strain detector comprises a strain gauge attached on the valve shaft.
  • valve opening detection means used in the butterfly valve of the present invention includes an angle sensor connected to the valve shaft.
  • the angle sensor preferably comprises a potentiometer or a rotary encoder.
  • the butterfly valve of the present invention can be designed either as a so-called central-type valve in which the valve member is fixed to the valve shaft at a central axis of the valve member, or so-called an eccentric-type valve in which the valve member is fixed to the valve shaft at an eccentric axis of the valve member.
  • the estimation of the function through the experiment may be based on an assumption that a linear proportional relationship exists between the dynamic torque and the flow rate when the valve opening is fixed. In such a case, the experiment and the estimation can be simplified.
  • the method of the invention for determining the flow rate may employ a chart which shows the flow rate values in relation to the valve opening and the dynamic torque. Such a chart is preferably obtained through an experiment.
  • the determination of the flow rate in the measuring method of the present invention can be performed rapidly and easily when a suitable computer is used.
  • the butterfly valve is controlled such that the flow rate determined by the measuring method of the present invention approaches the desired flow rate which can be externally set. In such a case, a rapid control of the flow rate can be realized through a feedback of the measured data.
  • FIG. 1 is a partly-sectioned perspective view of a portion of an embodiment of the butterfly valve according to the present invention
  • FIG. 1A is a schematic view of an eccentric-type valve member in accordance with another embodiment of the invention.
  • FIG. 2 is a schematic diagram of an embodiment of the present invention
  • FIGS. 3 to 6 are graphs showing the functions used in the present invention.
  • FIG. 7 is schematic diagram of a system used in an experiment conducted on an embodiment of the present invention.
  • FIGS. 10 and 11 are graphs showing the functions derived from the results of experiment.
  • the butterfly valve has a main body 1 and a valve member 2 having an outside diameter slightly smaller than the inside diameter of the main body 1.
  • the valve member 2 is rotatably supported in the main body 1 by means of a valve shaft 3.
  • the arrangement of the valve member 2 to the valve shaft 3 is so-called central-type in which the valve member 2 is fixed to the valve shaft 3 at the central axis of the valve member 2.
  • This is only illustrative and the arrangement may be so-called eccentric type in which the valve member 2A is fixed to the valve shaft 3A at the eccentric axis of the valve member 2 as shown in FIG. 1A.
  • the valve shaft 3 extends through a shaft bore formed in the main body 1.
  • a gland packing 7 and a seal ring 8 are disposed between the valve shaft 3 and the wall of the shaft bore, in order to provide a seal therebetween while allowing the valve shaft 3 to rotate with respect to the main body 1.
  • a smooth rotation of the valve shaft 3 is ensured by a shaft bearing 6.
  • the main body 1 of this butterfly valve is connected to a pipe 100 in a manner known per se as shown in FIG. 2.
  • the pipe 100 is usually made of a metal or a plastic and the diameter of the pipe 100 generally ranges between several millimeters and several meters. Preferably, the diameter of the pipe 100 ranges between more than 10 millimeters and several meters, more preferably between several tens of millimeters and several meters.
  • a plurality of classes of bufferfly valve having different sizes of the main body 1 are manufactured and the size of the main body 1 of which conforms with the pipe diameter is used.
  • a higher degree of conformity between the inside diameter of the pipe 100 and the inside diameter of the main body 1 reduces any turbulency of flow of the fluid which is generated at the juncture between the pipe 100 and the main body 1.
  • the state of the flow of fluid coming into the main body 1 more closely approximates the state of laminar flow. This feature is advantageous particularly in the measurement of large flow rates.
  • the flow passage is not completely shut off even when the valve opening is 0°.
  • the butterfly valve of the invention may have a seat ring or an "O" ring made of rubber. Teflon [Trade name] or metal etc. on the inner peripheral surface of the main body 1 so as to be contacted by the peripheral edge of the valve member 2 thereby to completely shut off the flow of the fluid when the valve opening is 0°.
  • the arrangement also may be such that another butterfly valve or another kind of valve which can completely close the flow passage is disposed in the pipe 100 in series to the butterfly valve of the present invention.
  • An actuator 11 shown in FIG. 2 is operatively connected to one end 9 of the valve shaft 3 in a manner known per se.
  • the actuator 11 is capable of rotating the valve shaft 3 so as to cause the valve member 2 to rotate about the axis of the valve shaft 3.
  • the actuator 11 is also capable of fixing the valve shaft 3 and, hence, the valve member 2 at a predetermined angle, thus determining the valve opening of the butterfly valve.
  • Various types of actuators such as an electric actuator, a pneumatic actuator, a diaphragm actuator and a solenoid-type actuator can be used as the actuator 11.
  • the use of the actuator 11 is not essential. Namely, the butterfly valve of the invention may be constructed such that the valve shaft 3 is rotated manually.
  • a strain detector 12 capable of detecting a minute twist of the valve shaft 3 is provided on the valve shaft 3.
  • a known strain gauge is preferably used as the strain detector 12.
  • the amount of twist detected by the strain detector 12 is delivered to a torque converter 13 which converts the detected amount of the twist into the dynamic torque which acts on the valve member 2 tending to rotate the valve member 2 about the axis of the valve shaft 3, and outputs the thus determined value of dynamic torque.
  • the strain detector 12 and the torque converter 13 in combination provide a torque detection means 14.
  • Various other torque detectors can be used as the means for detecting the dynamic torque applied to the valve member 2 around the valve shaft 3 by the fluid. It is therefore possible to use an optimum dynamic torque detector taking into account both the measurement precision and the cost.
  • the strain detector 12 In order to prevent the bending strain generated in the valve shaft 3 from being included in the signal obtained from the stain detector 12 which is intended for detecting the twist of the valve shaft 3, there are two shaft bearings 6 on each side of the strain detector 12 so as to prevent the bending strain from being transmitted to the strain detector 12. It is preferred that the position of the strain detector 12 on the valve shaft 3 is determined such that the dynamic torque applied to the valve member 2 is more directly transmitted to the strain detector 12. From this point of view, the strain detector 12 is disposed on a portion of the valve shaft 3 which is comparatively close to the valve member 2 across the shaft bearings 6 and the gland packing 7. Such an arrangement enhances the precision of detection of the dynamic torque applied to the valve member 2.
  • the rotation of the valve shaft 3 is transmitted to a potentiometer 15 as an angle sensor, through a gear 10 formed on the outer peripheral surface of the valve shaft 3 and a gear 4 meshing with the gear 10.
  • the potentiometer 15 is capable of delivering a signal indicative of the amount of rotation of the valve shaft 3 to a valve opening converter 16 which converts this signal into the degree of the valve opening of the butterfly valve.
  • the gear ratio between the gear 4 and the gear 10 is so selected that the angle of rotation of the valve shaft 3 is amplified by the factor of two, thus enabling a higher precision of detection of the valve opening.
  • the gear 10, gear 4, potentiometer 15 and the valve opening converter 16 in combination provide a valve opening detection means 17.
  • the potentiometer 15 may be incorporated in the actuator 11. It is also possible to arrange such that the rotation of the valve shaft 3 is transmitted to a separate potentiometer 15 through other gears incorporated in the actuator 11.
  • the valve opening detection means 17 may have a rotary encoder which is connected to the gear 4 or 10 and which is capable of directly or indirectly measuring the rotation angle of the valve shaft 3 in terms of the number of the teeth of the gear 4 or 10.
  • the valve opening detection means 17 may be installed on a portion of the valve shaft 3 which is on the opposite side of the valve member 2 with respect to the torque detection means 14.
  • the described constructions of the valve opening detection means 17 is only illustrative and various other known arrangements are usable as the valve opening detection means 17.
  • the construction of the butterfly valve of the present invention is shown in the form of a schematic diagram in FIG. 2.
  • the simplest way of determination is to substitute the torque Tm and the opening ⁇ m to the formula (2) which expresses the flow rate Q as a function G of the dynamic torque T and the valve opening ⁇ which is peculiar to each butterfly valve and which can be determined beforehand.
  • This operation can be done without difficulty by means of, for example, a desk-top calculator, so that the flow rate Qm can be definitely determined in accordance with the measured values of the torque Tm and the opening ⁇ m.
  • a chart showing the values of the flow rate Q in relation to the torque T and the opening ⁇ is prepared beforehand, so that the flow rate Qm is located on this chart in accordance with the measured values of the torque Tm and the opening ⁇ m. It is thus possible to achieve the first object of the invention by the combination of the torque detection means 14 and the valve opening detection means 17.
  • the torque Tm derived from the torque detection means 14 and the opening ⁇ m derived from the valve opening detection means 17 are input to the flowrate computation means 18.
  • the flow rate computation means 18 includes a memory device 19 which is capable of storing the aforementioned function G of the formula (2) which is peculiar to each butterfly valve and which can be determined beforehand.
  • the flow rate computation means 18 also includes an arithmetic operation device 20 which comprises the valve of the function G of the formula (2) using the measured values of the torque Tm and the opening ⁇ m.
  • the flow rate computation means 18 computes and outputs the flow rate Qm upon receipt of the measured values of the torque Tm and the opening ⁇ m.
  • the butterfly valve of this embodiment can be applied to a variety of types of liquids such as water, alcohol, lubrication oil, fuel oil, petroleum and so forth.
  • the butterfly valve also is applicable to various gases such air, combustion gas, fuel gas, steam and so forth, provided that the precision of the torque detection means is enhanced.
  • the flow rate Qm output from the flow rate computation means 18 is input to the control means 21 in which a desired flow rate Qd is set externally.
  • the external setting of the flow rate Qd may be conducted by a known remote operation means through a suitable tele-communication device or may be done at the site of the butterfly valve.
  • the control means 21 operates to compute the difference between the flow rate Qm and the flow rate Qd and delivers an instruction to the actuator 11 so as to cause the actuator 11 to rotate the valve member 2 in such a direction as to reduce the difference.
  • the butterfly valve is disposed in a portion of the pipe 100 through which a fluid to be controlled flows.
  • the fluid such as water, oil or the like flows through the pipe 100 at a flow rate which is determined by the differential pressure of the fluid across the butterfly valve and the degree of the valve opening of the butterfly valve.
  • the valve opening is variable between 0° and 90°.
  • the valve opening of 0° means that the valve member has been rotated to the position of the minimum opening so that the fluid is allowed to flow only through a minute gap left between the valve member 2 and the main body 1.
  • the valve opening of 90° means the state in which the valve is fully opened so that the differntial pressure of the fluid across the butterfly valve is minimized. It is assumed here that the fluid is flowing through the butterfly valve which is set at a desired valve opening.
  • the valve opening detection means 17 detects the valve opening and delivers the same as the opening ⁇ m.
  • the torque detection means 14 detects the dynamic torque which is produced by the fluid and which acts on the valve member 2 so as to tend to rotate the valve member 2 about the axis of the valve shaft 3 and delivers the thus detected torque as the torque Tm.
  • the flow rate computation means 18 executes the computation of the function G of the formula (2) or the function G' of the formula (10) so as to determine the flow rate Qm corresponding to the opening ⁇ m and the torque Tm, and delivers this flow rate Qm to the control means 21.
  • the control means 21 Upon receipt of the flow rate Qm, the control means 21 operates to determine any difference between the flow rate Qm and the desired flow rate Qd which is externally set and, if there is any difference, delivers an instruction to the actuator 11 so as to enable the actuator 11 to actuate the valve shaft 3 in such a direction as to reduce the difference.
  • the instruction given by the control means 21 to the actuator 11 is sorted into the following three types:
  • the described embodiment employs a closed feedback loop which enables the actuator 11 to operate in such a manner as to cause the measured flow rate Qm to infinitely approach the desired flow rate Qd.
  • the instruction delivered by the control means 21 to the actuator 11 is ceased when the measured value of the flow rate Qm has become equal to the flow rate Qd as a result of operation of the actuator 11, so that the actuator 11 stops to operate so as to fix the valve member 2, thereby allowing the instant flow rate Qm to be maintained.
  • Any change in the pressure at the upstream side and/or the downstream side of the butterfly valve causes the flow rate Qm to be changed, even after the coincidence between the measured flow rate Qm and the flow rate Qd has been achieved.
  • the above-mentioned closed feedback loop enables the valve opening to be varied without delay to recover the flow rate Qm coinciding with the flow rate Qd.
  • the valve member 2 itself functions both as a sensor for producing a flow rate information and a restriction member which restricts the flow of the fluid in accordance with the thus obtained flow rate information.
  • the measurement of the flow rate can be conducted directly and at a high degree of precision without suffering from any error which may otherwise be caused by spacing between the sensor and the butterfly valve and by a delay of time.
  • ⁇ represents a correction coefficient employed for the purpose of compensation for a change in the result of measurement caused by a change in factors such as specific gravity, viscosity and temperature of the fluid.
  • the flow rate Q is in proportion to the root of the differential pressure ⁇ P, if the opening ⁇ is fixed, and the proportion constant is ⁇ Cv, as can be seen from the formula (11).
  • the formula (13) means that, if the opening ⁇ is fixed, the flow rate Q is proportional to the torque T and the proportion constant is ( ⁇ / ⁇ ) ⁇ (Cv/Cu). It is therefore possible to determine the function G( ⁇ ,T) by determining, through an experiment, values of ff( ⁇ ) and gg( ⁇ ) with varying the opening ⁇ .
  • FIG. 7 shows the outline of the apparatus.
  • a pressure gauge 22 is capable of measuring the fluid pressure P 1 at the upstream side of the butterfly valve 27, while a differential pressure meter 23 measures the pressure difference ⁇ P across the butterfly valve 27.
  • the flow rate Q of the fluid flowing through the butterfly valve 27 is measured by an electromagnetic flowmeter 24.
  • the fluid is supplied by a fluid supply device 25 to the butterfly valve 27, as well as to a bypass valve 26 which capable of changing its opening degree for the purpose of setting a desired flow rate through the butterfly valve 27.
  • the values of the torque T, differential pressure ⁇ P, pressure P 1 and the flow rate Q are measured for each unit opening ⁇ of the butterfly valve 27, while controlling the degrees of the opening ⁇ of the bypass valve 26 and the opening of the butterfly valve 27 by means of a D/A converter.
  • the measurement is conducted under the following conditions: sampling frequency 200 Hz; sample number 200 samples/sec; interval of setting of the opening ⁇ 0.2 mA; range of setting of the opening ⁇ 20 mA to 4 mA, interval of setting of the bypass valve opening 1 mA; and range of setting of the bypass valve opening 20 mA to 10 mA.
  • Water maintained at a normal temperature is used as the fluid.
  • the measurement is executed by sequentially executing the following steps (a) to (g).
  • step (g) To repeat step (a) for a predetermined time, thus completing the whole process.
  • FIGS. 8 and 9 The Cv and Cu values in relation to the measured opening ⁇ m, obtained as results of the experiment, are shown in FIGS. 8 and 9, respectively.
  • discrete dots represent the values obtained through the experiment.
  • the function ff( ⁇ ) of a formula (14) and the function gg( ⁇ ) of a formula (15) are determined, respectively, by applying four-degree approximate expression and five-degree approximate expression, respectively, to the values of these discrete dots.
  • the Cv and Cu values are determined as follows for any opening ⁇ as follows.
  • the flow rate Q can be computed from the measured opening ⁇ and the measured torque T from the formula (13), without requiring measurement of the differential pressure ⁇ P, insofar as this butterfly valve 27 or a butterfly valve of the same design as this valve is concerned.
  • the function F( ⁇ , ⁇ P) and H( ⁇ , ⁇ P) may be determined in accordance with an experimental formula from the flow rate Q, the opening ⁇ , the differential pressure ⁇ P and the torque T. It is to be noted that the function G( ⁇ , T) may be determined as an experimental formula directly from the results of the experiment, although in the described embodiment the function G ( ⁇ , T) is determined after the determination of the functions ff( ⁇ ) and gg( ⁇ ).
  • the butterfly valve of the present invention has a valve opening detection means capable of detecting the degree of the valve opening of the butterfly valve and a torque detection means capable of detecting the dynamic torque produced by the flow of the fluid acting on the valve member around the axis of the valve shaft. Therefore, by determining beforehand a relationship between the flow rate and the values of the valve opening and the dynamic torque peculiar to the butterfly valve, it is possible to determine the flow rate from the measured values of the valve opening and the dynamic torque.
  • the valve member has not only a function for restricting the flow of the fluid but also a function for sensing the flow rate.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Electromagnetism (AREA)
  • Indication Of The Valve Opening Or Closing Status (AREA)
  • Measuring Volume Flow (AREA)
  • Lift Valve (AREA)
  • Details Of Valves (AREA)
  • Indicating Or Recording The Presence, Absence, Or Direction Of Movement (AREA)
  • Flow Control (AREA)
US07/594,866 1989-02-17 1990-10-09 Butterfly valve having a function for measuring a flow rate and method of measuring a flow rate with a butterfly valve Expired - Lifetime USRE33649E (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP1-38965 1989-02-17
JP1038965A JP2574449B2 (ja) 1989-02-17 1989-02-17 バタフライ弁

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US07/347,621 Reissue US4926903A (en) 1989-05-05 1989-05-05 Butterfly valve having a function for measuring a flow rate and method of measuring a flow rate with a butterfly valve

Publications (1)

Publication Number Publication Date
USRE33649E true USRE33649E (en) 1991-07-30

Family

ID=12539877

Family Applications (1)

Application Number Title Priority Date Filing Date
US07/594,866 Expired - Lifetime USRE33649E (en) 1989-02-17 1990-10-09 Butterfly valve having a function for measuring a flow rate and method of measuring a flow rate with a butterfly valve

Country Status (18)

Country Link
US (1) USRE33649E (pt)
EP (1) EP0382964B1 (pt)
JP (1) JP2574449B2 (pt)
KR (1) KR940011014B1 (pt)
CN (1) CN1018572B (pt)
AT (1) ATE120274T1 (pt)
AU (1) AU614839B2 (pt)
BR (1) BR8902580A (pt)
CA (1) CA1335900C (pt)
DE (1) DE68921872T2 (pt)
DK (1) DK237389A (pt)
ES (1) ES2069581T3 (pt)
FI (1) FI95074C (pt)
MX (1) MX173847B (pt)
MY (1) MY105957A (pt)
NO (1) NO176854C (pt)
NZ (1) NZ229129A (pt)
PT (1) PT90551B (pt)

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5487302A (en) * 1993-03-01 1996-01-30 Lockheed Martin Energy Systems, Inc. Method and system for measuring gate valve clearances and seating force
US5609183A (en) * 1994-02-16 1997-03-11 Btr Plc Butterfly valve with sensing coil
US6644133B2 (en) * 2001-02-15 2003-11-11 Schneider Automation, Inc. Flow meter module for a controller
US20040055393A1 (en) * 2001-02-15 2004-03-25 Schneider Automation Inc Controller for monitoring fluid flow volume
US20050127317A1 (en) * 2003-12-11 2005-06-16 Rebello Peter J. Metering ball valve and method of determining fluid flow therethrough
US20100264349A1 (en) * 2009-04-16 2010-10-21 Z & J Technologies Gmbh Double-disc gate valve
US20110126637A1 (en) * 2009-12-01 2011-06-02 Battelle Energy Alliance, Llc Force measuring valve assemblies, systems including such valve assemblies and related methods
US20110155933A1 (en) * 2005-10-12 2011-06-30 Buehring Heiko Leak detector
US20130319545A1 (en) * 2012-05-31 2013-12-05 Trox Gmbh Butterfly valve for arrangement in a flow duct of an air-conditioning installation
US20140261714A1 (en) * 2013-03-15 2014-09-18 Schneider Electric Buildings, Llc Advanced Valve Actuator With True Flow Feedback
US20160040802A1 (en) * 2012-05-25 2016-02-11 Mueller International, Llc Position indicator for valves
US20160139614A1 (en) * 2014-11-13 2016-05-19 Toyota Jidosha Kabushiki Kaisha Valve control apparatus and valve control method
US10502172B2 (en) * 2014-07-22 2019-12-10 Delphi Technologies Ip Limited Fuel injector with device for detecting needle position
US10564020B2 (en) * 2015-09-04 2020-02-18 Halliburton Energy Services, Inc. Flow-rate monitoring system for a pressure pump
US10895254B2 (en) 2015-09-04 2021-01-19 Halliburton Energy Services, Inc. Pressure pump valve monitoring system
US10914302B2 (en) 2015-09-04 2021-02-09 Halliburton Energy Services, Inc. Single-sensor analysis system
US10927831B2 (en) 2015-09-04 2021-02-23 Halliburton Energy Services, Inc. Monitoring system for pressure pump cavitation
US10975985B2 (en) * 2017-12-05 2021-04-13 Flowserve Management Company Position sensors for valve systems and related assemblies, systems and methods
US10995594B2 (en) 2015-09-04 2021-05-04 Halliburton Energy Services, Inc. Critical valve performance monitoring system
CN114135711A (zh) * 2021-12-08 2022-03-04 中国航发南方工业有限公司 一种新型伺服液动式线性蝶形调节阀
US11486385B2 (en) 2016-09-15 2022-11-01 Halliburton Energy Services, Inc. Pressure pump balancing system
US11499544B2 (en) 2016-08-31 2022-11-15 Halliburton Energy Services, Inc. Pressure pump performance monitoring system using torque measurements

Families Citing this family (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL9001562A (nl) * 1990-07-09 1992-02-03 Keystone Int Meet- en regelafsluiter.
JP2600763Y2 (ja) * 1991-05-20 1999-10-25 アネルバ株式会社 弁装置
ES2078135B1 (es) * 1991-12-10 1996-08-16 Quinones Alfredo Lopez Contador de gas perfeccionado.
DE19612370C1 (de) * 1996-03-28 1997-11-20 Samson Ag Verfahren und Vorrichtung zur Durchflußbestimmung eines Prozeßmediums an einem Stellgerät
GB9914500D0 (en) * 1999-06-22 1999-08-25 Axon Instr Limited Flow meter
DE102004005977A1 (de) * 2004-02-06 2005-08-25 Volkswagen Ag Vorrichtung zum Messen eines Strömungsparameters einer Wirbelströmung
EP2066880A1 (en) * 2006-09-19 2009-06-10 Industriell Plåtproduktion Ab Exhaust gas system
CN101852661A (zh) * 2009-03-31 2010-10-06 项美根 阀门扭矩连续测试装置及其测试方法
JP5397351B2 (ja) * 2010-08-23 2014-01-22 株式会社デンソー 流量検出装置
US9200725B2 (en) * 2010-11-16 2015-12-01 Fujikin Incorporated Opening degree detection device for manual valve
CN103748391B (zh) * 2011-06-02 2016-04-27 高级阀私人有限公司 手动平衡阀
KR101268481B1 (ko) * 2011-08-12 2013-06-04 한국수력원자력 주식회사 밸브패킹 마찰계수 시험장치 및 그 방법
US10295080B2 (en) 2012-12-11 2019-05-21 Schneider Electric Buildings, Llc Fast attachment open end direct mount damper and valve actuator
CN105531520B (zh) 2013-03-15 2018-08-17 施耐德电气建筑有限公司 具有集成能量计量的先进阀门致动器
JP6427370B2 (ja) * 2013-09-30 2018-11-21 株式会社フジキン 回転弁
CN104132180A (zh) * 2014-07-07 2014-11-05 中原工学院 阀门执行器主轴位置的测量传动机构
DE102014110161A1 (de) 2014-07-18 2016-01-21 Krones Aktiengesellschaft Verfahren zum Befüllen eines Behälters mit einem Füllprodukt mittels eines Proportionalventils
ES2531064A1 (es) * 2014-09-09 2015-03-10 Univ Madrid Politecnica Procedimiento y sistema para la medición de caudal de agua con llaves de mariposa
CN104407630B (zh) * 2014-11-19 2017-09-22 江苏天泽环保科技有限公司 一种基于传感器网络的流体流量控制阀的控制方法
CN104455641B (zh) * 2014-12-04 2017-05-17 天津埃柯特测控技术有限公司 检测级执行机构
CN104748809B (zh) * 2015-03-30 2017-12-26 王向乔 基于调压器的智能计量仪及计量方法
JP2016192039A (ja) * 2015-03-31 2016-11-10 アズビル株式会社 流量制御弁
US9739651B1 (en) * 2016-05-23 2017-08-22 Saudi Arabian Oil Company Variable cone flow meter
JP6753791B2 (ja) * 2017-02-07 2020-09-09 アズビル株式会社 メンテナンス時期予測装置、流量制御装置およびメンテナンス時期予測方法
KR102165227B1 (ko) * 2018-11-15 2020-10-13 김기덕 스마트 밸브 시스템
CN110185806A (zh) * 2019-06-20 2019-08-30 江苏百时得计量设备有限公司 一种测控一体式阀门流量计

Citations (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU257781A1 (ru) * П. П. Человань , Л. И. Чернощеков Датчик расхода жидкости
US1877810A (en) * 1926-09-07 1932-09-20 Waterworks Supply Company Indicating and controlling system
GB631973A (en) * 1947-02-27 1949-11-14 Richard Harvey Webb Improvements in or relating to flow-meters
US2501583A (en) * 1946-06-13 1950-03-21 Honeywell Regulator Co Electric motor control device
US2662547A (en) * 1946-09-03 1953-12-15 Garrett Corp Flow control apparatus
US2723615A (en) * 1952-09-12 1955-11-15 Garrett Corp System and apparatus for pressurization of aircraft cabins
GB919593A (en) * 1960-11-19 1963-02-27 Paul Flatten Improvements in and relating to the measuring of the velocity of fluid substances and/or of the mass flow
US3225785A (en) * 1963-03-01 1965-12-28 Cons Electrodynamics Corp Servo-system for fluid flow regulating valves
US3240062A (en) * 1962-12-05 1966-03-15 Fredriksson Curt Johan Flow-controlling apparatus
US3331388A (en) * 1965-05-04 1967-07-18 Caterpillar Tractor Co Control system and fluid flow transducer therefor
US3776249A (en) * 1972-07-14 1973-12-04 Valve M Co Pipeline flow control system and method
DE2614811A1 (de) * 1976-04-02 1977-10-13 Siemens Ag Durchflussmessgeraet mit einem plattenfoermigen messkoerper
US4112885A (en) * 1975-05-23 1978-09-12 Nippon Soken, Inc. Throttle valve control system for an internal combustion engine
US4157661A (en) * 1978-03-07 1979-06-12 Milltronics Limited Flowmeters
JPS55142169A (en) * 1979-04-20 1980-11-06 Tomoe Gijutsu Kenkyusho:Kk Seat ring of butterfly valve
JPS5628355A (en) * 1979-05-15 1981-03-19 Tomoe Gijutsu Kenkyusho:Kk Sealing mechanism for butterfly valve
US4428242A (en) * 1982-03-11 1984-01-31 Amsted Industries Incorporated Flowmeter using twisting torque
JPS621117A (ja) * 1985-06-26 1987-01-07 Hitachi Maxell Ltd 磁気記録媒体
JPS62270873A (ja) * 1986-05-16 1987-11-25 Tomoe Gijutsu Kenkyusho:Kk 流量制御特性を有するバタフライ弁
JPS63120973A (ja) * 1986-11-06 1988-05-25 Tomoe Gijutsu Kenkyusho:Kk 自動制御弁の作動方法

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU530314B2 (en) * 1978-09-01 1983-07-14 Advanced Medical Technologies, Inc. Apparatus for controlling the flow of intravenous fluid to patient
GB2077434B (en) * 1980-05-30 1984-04-26 Millar John Ascertaining flow rate through valves or pumps
JPS60120218A (ja) * 1983-11-29 1985-06-27 アムステッド・インダストリ−ス・イン・コ−ポレ−テッド 流量測定装置と流量測定−制御弁並びに流量測定法
DE3513543A1 (de) * 1985-04-16 1986-10-16 Hydrotechnik Gmbh, 6250 Limburg Klappendurchflussmesser
JPS62223622A (ja) * 1986-03-25 1987-10-01 Kurifu Kk 風量制御測定方法並びに装置

Patent Citations (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU257781A1 (ru) * П. П. Человань , Л. И. Чернощеков Датчик расхода жидкости
US1877810A (en) * 1926-09-07 1932-09-20 Waterworks Supply Company Indicating and controlling system
US2501583A (en) * 1946-06-13 1950-03-21 Honeywell Regulator Co Electric motor control device
US2662547A (en) * 1946-09-03 1953-12-15 Garrett Corp Flow control apparatus
GB631973A (en) * 1947-02-27 1949-11-14 Richard Harvey Webb Improvements in or relating to flow-meters
US2723615A (en) * 1952-09-12 1955-11-15 Garrett Corp System and apparatus for pressurization of aircraft cabins
GB919593A (en) * 1960-11-19 1963-02-27 Paul Flatten Improvements in and relating to the measuring of the velocity of fluid substances and/or of the mass flow
US3240062A (en) * 1962-12-05 1966-03-15 Fredriksson Curt Johan Flow-controlling apparatus
US3225785A (en) * 1963-03-01 1965-12-28 Cons Electrodynamics Corp Servo-system for fluid flow regulating valves
US3331388A (en) * 1965-05-04 1967-07-18 Caterpillar Tractor Co Control system and fluid flow transducer therefor
US3776249A (en) * 1972-07-14 1973-12-04 Valve M Co Pipeline flow control system and method
US4112885A (en) * 1975-05-23 1978-09-12 Nippon Soken, Inc. Throttle valve control system for an internal combustion engine
DE2614811A1 (de) * 1976-04-02 1977-10-13 Siemens Ag Durchflussmessgeraet mit einem plattenfoermigen messkoerper
US4157661A (en) * 1978-03-07 1979-06-12 Milltronics Limited Flowmeters
JPS55142169A (en) * 1979-04-20 1980-11-06 Tomoe Gijutsu Kenkyusho:Kk Seat ring of butterfly valve
JPS5628355A (en) * 1979-05-15 1981-03-19 Tomoe Gijutsu Kenkyusho:Kk Sealing mechanism for butterfly valve
US4428242A (en) * 1982-03-11 1984-01-31 Amsted Industries Incorporated Flowmeter using twisting torque
JPS621117A (ja) * 1985-06-26 1987-01-07 Hitachi Maxell Ltd 磁気記録媒体
JPS62270873A (ja) * 1986-05-16 1987-11-25 Tomoe Gijutsu Kenkyusho:Kk 流量制御特性を有するバタフライ弁
JPS63120973A (ja) * 1986-11-06 1988-05-25 Tomoe Gijutsu Kenkyusho:Kk 自動制御弁の作動方法

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
"Study on Hydrodynamic Characteristics of a Butterfly Valve", (a doctoral theses), Kazuhiko Ogawa, Jan. 1986, Kobe Univ., Japan.
ISA Handbook of Control Valves, 2nd Edition, pp. 123 and 124 published in Pennsylvania, U.S.A. (date unknown). *
Study on Hydrodynamic Characteristics of a Butterfly Valve , (a doctoral theses), Kazuhiko Ogawa, Jan. 1986, Kobe Univ., Japan. *

Cited By (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5487302A (en) * 1993-03-01 1996-01-30 Lockheed Martin Energy Systems, Inc. Method and system for measuring gate valve clearances and seating force
US5609183A (en) * 1994-02-16 1997-03-11 Btr Plc Butterfly valve with sensing coil
US6644133B2 (en) * 2001-02-15 2003-11-11 Schneider Automation, Inc. Flow meter module for a controller
US20040055393A1 (en) * 2001-02-15 2004-03-25 Schneider Automation Inc Controller for monitoring fluid flow volume
US6792361B2 (en) * 2001-02-15 2004-09-14 Schneider Automation Inc. Controller for monitoring fluid flow volume
US20050127317A1 (en) * 2003-12-11 2005-06-16 Rebello Peter J. Metering ball valve and method of determining fluid flow therethrough
US8365581B2 (en) * 2005-10-12 2013-02-05 Airbus Operations Gmbh Valve for a leak detector
US20110155933A1 (en) * 2005-10-12 2011-06-30 Buehring Heiko Leak detector
US8413956B2 (en) * 2009-04-16 2013-04-09 Z & J Technologies Gmbh Double-disc gate valve
US20100264349A1 (en) * 2009-04-16 2010-10-21 Z & J Technologies Gmbh Double-disc gate valve
US8156822B2 (en) 2009-12-01 2012-04-17 Bettelle Energy Alliance, Llc Force measuring valve assemblies, systems including such valve assemblies and related methods
US20110126637A1 (en) * 2009-12-01 2011-06-02 Battelle Energy Alliance, Llc Force measuring valve assemblies, systems including such valve assemblies and related methods
US11125355B2 (en) 2012-05-25 2021-09-21 Mueller International, Llc Position indicator for valves
US9909687B2 (en) * 2012-05-25 2018-03-06 Mueller International, Llc Position indicator for valves
US20160040802A1 (en) * 2012-05-25 2016-02-11 Mueller International, Llc Position indicator for valves
US9562623B2 (en) 2012-05-25 2017-02-07 Mueller International, Llc Position indicator for valves
US20130319545A1 (en) * 2012-05-31 2013-12-05 Trox Gmbh Butterfly valve for arrangement in a flow duct of an air-conditioning installation
US9128490B2 (en) * 2012-05-31 2015-09-08 Trox Gmbh Butterfly valve for arrangement in a flow duct of an air-conditioning installation
US20140261714A1 (en) * 2013-03-15 2014-09-18 Schneider Electric Buildings, Llc Advanced Valve Actuator With True Flow Feedback
US9658628B2 (en) * 2013-03-15 2017-05-23 Schneider Electric Buildings, Llc Advanced valve actuator with true flow feedback
US10502172B2 (en) * 2014-07-22 2019-12-10 Delphi Technologies Ip Limited Fuel injector with device for detecting needle position
US20160139614A1 (en) * 2014-11-13 2016-05-19 Toyota Jidosha Kabushiki Kaisha Valve control apparatus and valve control method
US9880567B2 (en) * 2014-11-13 2018-01-30 Toyota Jidosha Kabushiki Kaisha Valve control apparatus and valve control method
US10564020B2 (en) * 2015-09-04 2020-02-18 Halliburton Energy Services, Inc. Flow-rate monitoring system for a pressure pump
US10895254B2 (en) 2015-09-04 2021-01-19 Halliburton Energy Services, Inc. Pressure pump valve monitoring system
US10914302B2 (en) 2015-09-04 2021-02-09 Halliburton Energy Services, Inc. Single-sensor analysis system
US10927831B2 (en) 2015-09-04 2021-02-23 Halliburton Energy Services, Inc. Monitoring system for pressure pump cavitation
US10995594B2 (en) 2015-09-04 2021-05-04 Halliburton Energy Services, Inc. Critical valve performance monitoring system
US11499544B2 (en) 2016-08-31 2022-11-15 Halliburton Energy Services, Inc. Pressure pump performance monitoring system using torque measurements
US11486385B2 (en) 2016-09-15 2022-11-01 Halliburton Energy Services, Inc. Pressure pump balancing system
US10975985B2 (en) * 2017-12-05 2021-04-13 Flowserve Management Company Position sensors for valve systems and related assemblies, systems and methods
CN114135711A (zh) * 2021-12-08 2022-03-04 中国航发南方工业有限公司 一种新型伺服液动式线性蝶形调节阀
CN114135711B (zh) * 2021-12-08 2023-11-03 中国航发南方工业有限公司 一种新型伺服液动式线性蝶形调节阀

Also Published As

Publication number Publication date
JP2574449B2 (ja) 1997-01-22
DE68921872D1 (de) 1995-04-27
NO176854C (no) 1995-06-07
FI95074B (fi) 1995-08-31
KR940011014B1 (ko) 1994-11-22
CN1018572B (zh) 1992-10-07
CN1044978A (zh) 1990-08-29
DK237389A (da) 1990-08-18
NZ229129A (en) 1990-11-27
JPH02216418A (ja) 1990-08-29
MX173847B (es) 1994-04-05
FI95074C (fi) 1995-12-11
DE68921872T2 (de) 1995-07-27
DK237389D0 (da) 1989-05-16
FI892168A (fi) 1990-08-18
PT90551A (pt) 1990-08-31
ES2069581T3 (es) 1995-05-16
BR8902580A (pt) 1990-11-20
AU614839B2 (en) 1991-09-12
NO176854B (no) 1995-02-27
EP0382964A2 (en) 1990-08-22
AU3469389A (en) 1990-08-23
CA1335900C (en) 1995-06-13
EP0382964B1 (en) 1995-03-22
NO891911D0 (no) 1989-05-10
KR900013294A (ko) 1990-09-05
FI892168A0 (fi) 1989-05-05
EP0382964A3 (en) 1991-08-07
NO891911L (no) 1990-08-20
PT90551B (pt) 1995-09-12
MY105957A (en) 1995-02-28
ATE120274T1 (de) 1995-04-15

Similar Documents

Publication Publication Date Title
USRE33649E (en) Butterfly valve having a function for measuring a flow rate and method of measuring a flow rate with a butterfly valve
US4926903A (en) Butterfly valve having a function for measuring a flow rate and method of measuring a flow rate with a butterfly valve
US5251148A (en) Integrated process control valve
US5717146A (en) Device and method for measuring multi-phase fluid flow in a conduit having an abrupt gradual bend
US5905208A (en) System and method measuring fluid flow in a conduit
US6923074B2 (en) Ball valve with flow-rate gauge incorporated directly in the ball
US20050115612A1 (en) Flow regulating valve, flow rate measuring device, flow control device, and flow rate measuring method
US3686948A (en) Turbine-type volumetric flowmeters
JPH07174596A (ja) 流量測定機能を有するバタフライ弁及びバタフライ弁において流量を測定する方法
CN115307693B (zh) 一种多量程可调节式mems差压流量计
Zhu et al. Structural optimization to improve the dynamic performance of turbine flowmeters
CN216385818U (zh) 一种具有管径检测功能的流量计
CN210372039U (zh) 一种测控一体式阀门流量计
CN110596353A (zh) 一种原油含水率在线测量设备
CN101435729B (zh) 压力测量防堵塞方法及装置
CN2409496Y (zh) 一体化智能均速管质量流量计
AU763633B2 (en) Turbine meter with a rotor having accuracy enhancing rotor blades
CN115773790A (zh) 一种流量计及方法
SU1415061A1 (ru) Пневматический способ измерени среднего диаметра капилл рных трубок
Bertani et al. MULTIPHASE FLOW MEASUREMENT
Baker et al. On-site calibration of flow metering systems installed in buildings. Building science series
JPS61202120A (ja) 流量計測装置
Xu-Bin The simple economic elbow meter for flow measurement
SIEV et al. 2.12 Mass Flowmeters—Miscellaneous
Lucier et al. Positive Displacement Calibration for Laboratory Flowmeters

Legal Events

Date Code Title Description
FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12