Some standard content:
National Metrology Verification Regulation of the People's Republic of China JJG1029—2007
Vortex-shedding Flowmeter
2007-08-21 Issued
2007 November 21 Implementation
The General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China issued JJG 1029—2007
Verification Regulation of
Vortex-shedding Flowmeter
JIG 1029—2007
Replaces the vortex flow part in JJG198—1994
This regulation was approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on August 21, 2007, and came into effect on November 21, 2007.
Responsible unit: National Technical Committee on Flow and Capacity Measurement Main drafting unit: China Institute of Metrology, Beijing Institute of Metrology and Testing Science
Participating drafting unit: Liaoning Institute of Metrology, Dazhao Zhongjiang Instrument Co., Ltd.
Beijing Fischer Porter Instrument Co., Ltd.
Tianjin Yihuan Automation Instrument Co., Ltd.
Shanghai Yokogawa Electric Co., Ltd.
Emerson Process Control Co., Ltd.
This regulation is entrusted to the National Technical Committee on Flow and Capacity Measurement to interpret this regulation Main drafters:
JIG1029—2007
Duan Huiming (China Institute of Metrology) Yang Youtao (Beijing Institute of Metrology and Testing Science) Participating drafters:
Chen Mei (Liaoning Institute of Metrology)||tt ||Sun Huachun (Dalian Zhonglong Instrument Co., Ltd.)
Zhengsheng (Beijing Fischer-Porter Instrument Co., Ltd.) Liu Zhonghai (Tianjin Yihuan Baidong Instrument Co., Ltd.) Zhao Zhiliang (Shanghai Yokogawa Electric Co., Ltd.) Xiang Ziliang (Aimoniu Process Control Co., Ltd.) 3
References
Terms·
4Overview
Purpose and working principle
4.2Constitution and clamping method
5Metering performance requirements
5.1Accuracy level
5.2Repeatability
6General technical requirements
Random documents
Marking and nameplate
6.3Appearance.
Protective function
Sealing··
7Metering instrument control
7.1 Verification conditions
7.2 Verification items and methods
7.3 Processing of verification results
7.4 Verification cycle
Appendix A
Type evaluation personnel outline
JJG 1029—2007
Appendix B Verification certificate and verification result notice (inside page) Information 1
1 Scope
JJG 1029—2007
Verification procedure for vortex flowmeters
This procedure applies to type evaluation, initial verification, continued verification and in-use inspection of vortex flowmeters (hereinafter referred to as flowmeters):
2 Cited documents
The provisions contained in the following standards and regulations are the provisions of this regulation through reference. JF1001-1998 General terms and definitions JIF 1004-2004 Serial number Metrological terms and definitions GH17820-1999 Natural gas
GB50251-2003 Code for design of gas transmission pipeline engineering GB/T13609-1999 Guide for natural gas sampling GB3/T13610-2003 Analysis of natural gas components by gas chromatography GB/T17747.2-1999 Calculation of natural gas compressibility factor: Part 2: Calculation of H molar composition GB3836.1-200m Electrical apparatus for explosive gas atmospheres: Part 1: General requirements GB3836.2-2000 Electrical apparatus for explosive atmospheres Part 2: Flameproof type "d\ GH3836.3-2000 Electrical apparatus for explosive atmospheres Part 3: Increased safety type "e" OIM1. 125-1996 Vortex mctcrs used in nicasuring systcms for fluids should be used with the current version of the above references. 3 Terminology
In addition to the terms and definitions of JIF1001-1998 and JIF1004-2004, this program also uses the following terms
3.1 Biluff body Non-streamlined object that produces vortexes.
3.2 Probe (sensor)
Component that produces vortex frequency after the fluid vibration of the flow part. 3.3 Meter body (meter body)
Pipe section with baffles and probes
3.4 K coefficient (K-coefficient)
The number of pulses emitted by the flow meter when a unit volume of fluid flows through it. 3.5 Flow conditioner (flow conditiconer) Component that can reduce vortices and improve velocity distribution. 3.6 Flow factor (meier faclor）
Carry out actual flow calibration on the flowmeter and correct the flowmeter indication according to the result. The value is the standard instrument indication 1
JIG 1029-2007
The ratio of the estimated flow rate to the flow meter indication. It is generally expressed by a symbol. 4 Overview
4.1 Application and working principle
Flow meter is applicable to the measurement of gas, liquid and steam flow. The flow meter uses the gate vortex street principle: a vortex generator is placed in the fluid, and the fluid alternately separates and releases two rows of regularly staggered vortices on both sides of the downstream of the vortex generator. Within a certain Reynolds number range, the frequency of the vortex is related to the geometric dimensions of the vortex generator and the geometric dimensions of the pipeline. The frequency of the vortex is proportional to the flow rate, and this frequency can be detected by the probe.
In: b
Width of the baffle, m;
Average velocity of the fluid flowing through the flow meter, m island; Frequency of a vortex, Fz; bzxZ.net
Strouhal number (Strouhal number 4.2 Structure and output mode
4.2.1 Structure
The flowmeter is composed of a sensor and a flow meter display device or a flow integrator or a computer. 4.2.2 Output mode
The flowmeter output can be pulse output, analog output and digital communication. Metering performance requirements
5.1 Accuracy level
The table shows the accuracy level series of flowmeters. The accuracy level must be clearly stated in the flowmeter product manual and the flow nameplate.
Table 1 Flowmeter Accuracy Grade Series
Accuracy Grade
Maximum Permissible Error
Note: Boundary flow, the error for the corresponding flow is 0.2m 5.2 Repeatability
The repeatability of the flowmeter shall not exceed 1% of the absolute value of the maximum permissible error specified for the corresponding accuracy grade! 3.6 General Technical Requirements
6.1 Random Documents
6. ". "Flowmeter Instructions for Use. The name, model, manufacturing unit, and measurement medium shall be given in the instruction manual. 2
.IJG 1029—2007
Quality, operating pressure range, operating temperature range, suitable diameter, flow range, boundary flow (when the flow meter has this indicator), accuracy level, manufacturing measuring instrument license number, explosion-proof level and explosion-proof certificate number (for flammable and explosive occasions), protection level, etc.:
6.1.2 It is recommended that the flow meter inspected later be accompanied by the previous calibration certificate. 6.2 Marking and nameplate
6.2.1 The flow meter body has obvious flow markings. 6.2.2 The flow meter should have a nameplate. The nameplate should generally indicate the name and model: factory number, applicable medium, flow range, diameter, accuracy level, maximum working force, manufacturer and manufacturing date and other technical requirements. 6.3 Appearance
6 .3.1 The newly manufactured flow meter should have good surface treatment, without burrs, scratches, cracks, rust, rashes and coating peeling, and the cover should be flat and free of damage: 6.3.2 The welding of the flow meter body and vortex generator should be flat and smooth, without cold welding, debonding, etc. 6.3.3 The flow meter joints must be firm and reliable, and must not loosen or fall off due to vibration: 63,4 The numbers displayed on the flow meter should be clear and neat, and the text symbols indicating the functions should be complete, clear and correct:
6.3.5 The flow meter buttons should have moderate feel and no adhesion. 6.3.6 The flow meter printing should be accurate; the protective glass of the flow meter display numbers should have good transparency and no defects that distort the readings or hinder the display:
6.4 Protection function
The flowmeter should have K coefficient or flow meter protection function, which will leave permanent traces after modification: the value of flowmeter K coefficient or flowmeter factor should be consistent with the value set during the first inspection. 6.5 Sealing
Pass the verification medium to the maximum test pressure for 5 minutes, and the flow meter body and all connections will not leak. 7 Measuring instrument control
The measuring instrument and its control package shall be subject to type evaluation, initial verification, subsequent verification and in-use inspection. Attachment A is the outline of type evaluation:
7.1 Verification conditions
7 Requirements for flow standard devices
7.1.1.1 The flow standard device (hereinafter referred to as the device) and its supporting instruments shall have valid verification (or calibration or test) certificates
7.1.1.2 The expanded uncertainty (=2) of the device shall not exceed 1/2 of the absolute value of the maximum allowable error of the flowmeter being tested. 7.11 .3 When the vapor of the calibrated liquid is small and the ambient pressure is high, the device should be a closed type. 7.1.14 When it is necessary to measure the temperature of the fluid flowing through the flowmeter, the temperature can be measured from the temperature measuring hole 1 on the flowmeter body. If there is no temperature measuring hole on the flowmeter body, the temperature measurement position is determined according to the requirements of the flowmeter itself and relevant regulations. If there is no special requirement, the temperature measurement position is set at the downstream of the flow (2~5) (D is the pipe diameter, see below). The influence of the measurement error of the thermometer used on the calibration result should be less than 1/5 of the absolute value of the maximum allowable error of the flowmeter. 7.1.1.5 When it is necessary to measure the pressure of the fluid flowing out of the flowmeter, the pressure can be measured from the temperature measuring hole on the flowmeter body. 1029—2007
If the flow meter body has no pressure hole, the pressure measurement device should be determined according to the requirements of the flow meter itself. If there is no special requirement, the device should install a pressure gauge at the downstream side of the flow meter (2-7)). The axis of the pressure hole is perpendicular to the axis of the measuring pipe with a diameter of (4-12) mm. The influence of the measurement error of the pressure gauge on the calibration result should be less than 1/5 of the absolute value of the maximum allowable error of the flow meter
7.1.2 Calibration fluid
7.1.2,1 General conditions
(1) The calibration fluid should be a phase gas or liquid, filling the test pipe; (2) The calibration fluid should be clean and free of visible particles, fibers and other substances; (3) The density, viscosity and other physical parameters of the calibration medium should be close to those of the test medium: 7.1.2.2 Calibration liquid
(1) The pressure of the calibration liquid at any point in the pipeline system and the flowmeter should be higher than the saturated vapor pressure. For easily vaporized calibration liquids, there should be a certain back pressure downstream of the flowmeter. The recommended minimum back pressure is 1.3 times the saturated vapor pressure of the calibration liquid at the highest calibration temperature: (2) During the calibration process at each flow point, the liquid temperature change should not exceed 10.5℃. 7.1.2.3 Calibration gas
(1) The calibration gas should not contain impurities such as free water or oil, and the particle size of solid matter such as dust should be less than 5fm. (2) Alignment For flowmeters with an accuracy level not lower than level 1.0, during each calibration process at each flow point, the temperature change of the calibration gas should not exceed -0.5°C. For flowmeters with an accuracy level lower than level 1.5, during each calibration process at each flow point, the temperature change of the calibration body should not exceed +1°C. (3) When the calibration gas is natural gas, the natural gas quality should at least meet the requirements of Class II gas in (G17820). The natural gas density is 0.55·0.80. During the calibration process, the gas composition should be relatively stable. Natural gas sampling shall be carried out in accordance with GPT13609, and natural gas composition shall be carried out in accordance with GPT13610. (4) During the calibration process at each flow point, the pressure fluctuation shall not exceed 0.5%. 7.1.3 Calibration environmental conditions
7.1.3.1 The ambient temperature is generally (5--45); and the relative humidity is 35-95%; the relative humidity is (86 -106)kPa.
7.1.3.2 The AC power supply should be (220+22)V, and the frequency should be (5012.5)I: You can also use a suitable AC or DC power supply (such as 24V DC power supply) according to the requirements of the flow meter. 7.1.3.3 The external magnetic field is so small that the effect on the flow meter can be ignored. 7.1.3.4 The vibration and noise of the machine should be small enough to have negligible effect on the flow rate. 7.1.3.5 When the test medium is flammable or explosive fluids such as natural gas, all the test equipment and its function equipment, the test site shall meet the requirements of GB50251, and all equipment and environmental conditions shall meet the relevant safety and explosion-proof requirements of GB3836:
7.1.3.6 During the test, avoid or eliminate the disturbances close to the flow rate of the meter. 7.1.4 Installation of flow meter
7.1.4.1 The flow meter should be installed horizontally: Other installation methods can be specified by the flow meter manufacturer. When other installation methods are used, the flow meter should be installed in the rising section of the pipeline to ensure that the fluid fills the pipeline. 7.1.4.2 During installation, ensure that the fluid flow direction is close to the flow meter mark. 4
JJG 1029—2007
7.1.4.3 During installation, the flow meter measuring line should be aligned with the pipeline axis. 7.4.4 The connection between the flow meter and the pipeline should be free of leakage, and the seal at the connection should not protrude into the pipeline. 7.1.4.5 Principle 1 of calibration: All components of the flow meter should be sent for inspection together. 7.1.5 The time of each measurement should not be less than the shortest measurement time allowed by the device and the flow to be tested. 7.1.6 When the pulse output of the meter to be tested is used for calibration, the number of pulses recorded in one calibration should not be less than 10 times the reciprocal of the absolute value of the maximum allowable error of the flowmeter: 7.2 Verification items and verification methods Verification items The first verification, subsequent verification and in-use inspection items are listed in Table 2. Table 2 Verification items for first verification, subsequent verification and in-use inspection Verification items Random documents and appearance Indication error Complexity First verification Subsequent verification Note: "+" indicates items to be inspected, """ indicates items that cannot be inspected. 7.2.2 Random documents 7.2.2.1 Check the random documents, which shall meet the requirements of 6.1 of this regulation. 7.2.2.2 Check the appearance of the flowmeter by daily measurement. It shall meet the requirements of 6.2, 6.3 and 6.4 of this regulation. 7.2.3 Verification of indication error 7.2.3.1 Pre-operation inspection Preheat the power supply, and check the setting of flowmeter parameters according to the method specified in the flowmeter manual. 7.2.3.2 The flowmeter reaches 70% of the maximum verification flow rate. Run within the 100% range for at least 5 seconds, wait until the fluid temperature, pressure and flow rate are delayed, avoid the indication error and calibrate. 7.2.3.3 Control of calibration flow points and calibration times (1) The calibration flow points should include: 4mm, 4, 0.404eu and 4mx: For flow meters with an accuracy level of 0.5, add two flow points of 0.254mx and 0.70qmx. (2) During the calibration process, the deviation of the actual calibration flow rate from the set flow rate at each flow point should not exceed ±5% of the set flow rate or not exceed 1%9x.
(3) Each flow point shall be calibrated at least 3 times. For flow meters with type evaluation and accuracy level of 0.5, each flow point shall be calibrated at least 6 times: 7.2.3.4 Calibration procedure
(1) Adjust the flow rate to the set flow value and run until the fluid state is stable: (2) Record the initial indication of the device and the flow meter under test, and start the device and the flow meter under test for measurement at the same time. After running for a period of time according to the device operation requirements, stop the device and the flow meter under test at the same time and record the final indication of the device and the flow meter under test.
J.JG 1029—2007
(3) Calculate the cumulative flow value or cumulative pulse value or instantaneous flow value measured by the device and the flow meter respectively. 7.2.3.5 Calculation of indication error
(1) The relative indication error of a flow meter displaying the cumulative flow value or instantaneous flow value (or the instantaneous flow value corresponding to the analog output) for a single calibration shall be calculated according to formula (2): 2(0. ×100% or E, =%(g 100%
Where: E, ·Relative indication error of the flow meter under test at the ith calibration point, %; Q.
The cumulative flow value displayed by the flow meter at the ith calibration point, m; (2)
The instantaneous flow value displayed by the flow meter at the ith calibration point (or the instantaneous flow value corresponding to the analog output: it can be the average of the instantaneous flow values read multiple times during an experiment), m/h; -The instantaneous flow value installed at the ith calibration point, m\/h. (9,
When the device displays the cumulative flow, (); Calculate according to formula (3): (q.),=（Q.),×3600
Wherein: — calibration time,
For liquid flowmeter, (Q.) is calculated according to formula (4): (Q.): = (V),[13(0, -8m)] :L1+r(p-pm)lWherein: (V,),-actual liquid volume measured by the device at the ith calibration point during the ith calibration, m; β — —volume expansion coefficient of the liquid under calibration, 1/℃; (3)
,. —respectively the liquid temperature at the calibrator and flowmeter of the device at the ith calibration point during the ith calibration, ℃;
compression coefficient of the liquid under calibration, 1/Pa; ps,pr
respectively the liquid pressure at the standard device and flowmeter of the device at the ith calibration point during the ith calibration, Per||t When the difference between 0. and 0 is less than 5℃ and the difference between b and 0.1MPa is less than 0.1MPa, formula (4) can be simplified: (Q), (V,),;
When using the mass method device, it is necessary to measure the density of the liquid, and at the same time consider the influence of air buoyancy. According to formula (5), (6) or (7), the weighed mass M, is converted into the actual volume (V.): (V),
Where: - liquid density, kg/m;
o - narrow air density, kg/m;
e standard magnetic code density, kg/m,
JIG 1029--2007
When the device uses the code for calibration, the buoyancy correction is made according to formula (6): When the device does not use the basic code for calibration, the buoyancy correction is made according to formula (7)
For the gas flowmeter, (Q) is calculated according to formula (8): (Q)(V),z
Where: I, T are the thermodynamic temperatures of the gases at the standard device and the flowmeter during the first calibration at the calibration point and the second calibration respectively, K:
z. , product - the gas compression factor at the standard device and the flowmeter at the first calibration point, respectively,
(2) The relative indication error of the flowmeter displaying the cumulative flow or instantaneous flow (or the instantaneous flow value corresponding to the analog output) at each calibration flow point is calculated according to formula (9): E.=1E
War: E, the relative indication error of the flow at the first calibration point, %: n - the number of calibrations at the second calibration point;
, the relative indication error of the flowmeter at the first calibration point, %, (9)|| tt||（3）The relative error of the flow meter displaying the cumulative flow value or the instantaneous flow value (or the instantaneous flow value corresponding to the analog output) is calculated according to formula (10):
F=IIE,lux
Wu Where: E is the relative error of the flow meter, 1E,1mx is the maximum value of the relative error of the flow meter at each calibration point within the 4.g4max range, %【4】The K coefficient of the flow pulse output for a single calibration For liquid flow meters, the K coefficient of each calibration point for each calibration is 1 + 3t(0.)g (0.) 1 1- xl(p.) (p), K.=Q,
Wu Zhong:
K: - the coefficient of the first calibration point, (m) or: N - the pulse number of the flow rate measured at the first calibration point: Q.-the actual liquid volume measured at the first calibration point, m or L; 3
- the volume expansion coefficient of the liquid under the calibration state, (); (0..(0.).
- the fluid humidity at the standard device and the flow meter at the first calibration point; the compressibility coefficient of the liquid under the calibration state, Pa; the fluid gauge pressure at the standard device and the flow meter at the first calibration point, (p., (pm),
For gas flowmeters, the K coefficient of each calibration at each calibration point is calculated according to formula (12): N, paT.Z.
JJG 1029---2007
(5) The K coefficient of each flow point of the pulse output flow meter is calculated according to formula (13):-small
(6) The K coefficient of the pulse output flow meter is calculated according to formula (14): K=(K,)t(K)m
where: (K,)max, (K.)min are the maximum and minimum values of the K coefficient of each flow point within the range of qma:
(7) The relative indication error of the pulse output flow meter is: (K.)x -(K) ×100%
taq range, -
(K: +(K,)u-
(K)mx-K
Within the range of g, =
×100%
The relative indication error of the flowmeter shall comply with the requirements of 5.1 of this Regulation. 7.2.3.6 Repeatability of flow measurement
When each flow point is calibrated repeatedly n times, the repeatability of the flow point shall be evaluated according to formula (17): [(,E)
12(K -)
(E), = Kl(n-1 units
The repeatability of the flowmeter:
E,-[(E),rax
×100%
: [(E,),]mux——The flowmeter is respectively in the range of qg≤qnx,qmin
JJG 1029---2007
(5) The K coefficient of each flow point of the pulse output flow meter is calculated according to formula (13): - small
(6) The K coefficient of the pulse output flow meter is calculated according to formula (14): K=(K,)t(K)m
where: (K,)max, (K.)min are the maximum and minimum values of the K coefficient of each flow point within the range of qma:
(7) The relative indication error of the pulse output flow meter is: (K.)x -(K) ×100%
taq range, -
(K: +(K,)u-
(K)mx-K
Within the range of g, =
×100%
The relative indication error of the flowmeter shall comply with the requirements of 5.1 of this Regulation. 7.2.3.6 Repeatability of flow measurement
When each flow point is calibrated repeatedly n times, the repeatability of the flow point shall be evaluated according to formula (17): [(,E)
12(K -)
(E), = Kl(n-1 units
The repeatability of the flowmeter:
E,-[(E),rax
×100%
: [(E,),]mux——The flowmeter is respectively in the range of qg≤qnx,qmin
JJG 1029---2007
(5) The K coefficient of each flow point of the pulse output flow meter is calculated according to formula (13): - small
(6) The K coefficient of the pulse output flow meter is calculated according to formula (14): K=(K,)t(K)m
where: (K,)max, (K.)min are the maximum and minimum values of the K coefficient of each flow point within the range of qma:
(7) The relative indication error of the pulse output flow meter is: (K.)x -(K) ×100%
taq range, -
(K: +(K,)u-
(K)mx-K
Within the range of g, =
×100%
The relative indication error of the flowmeter shall comply with the requirements of 5.1 of this Regulation. 7.2.3.6 Repeatability of flow measurement
When each flow point is calibrated repeatedly n times, the repeatability of the flow point shall be evaluated according to formula (17): [(,E)
12(K -)
(E), = Kl(n-1 units
The repeatability of the flowmeter:
E,-[(E),rax
×100%
: [(E,),]mux——The flowmeter is respectively in the range of qg≤qnx,qmin
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