JJG 162-2009 English PDF (JJG162-2009)
JJG 162-2009 English PDF (JJG162-2009)
See Chinese contents: JJG 162-2009
JJG 162-2009: Verification Regulation of Cold Water Meter
NATIONAL METERING AND CALIBRATION REGULATION
OF THE PEOPLE REPUBLIC OF CHINA
Cold water meter
ISSUED ON: APRIL 08, 2009
IMPLEMENTED ON: APRIL 30, 2009
Issued by: General Administration of Quality Supervision, Inspection and Quarantine
Table of Contents
1 Scope ... 5
2 Normative references ... 5
3 Terms and units of measurement ... 6
3.1 Water meter and its composition ... 6
3.2 Metering characteristics ... 9
3.3 Operating conditions ... 10
3.4 Test conditions ... 12
3.5 Electronic devices and electrical devices ... 13
3.6 Unit of measurement ... 14
4 Overview ... 14
4.1 Principle and structure... 14
4.2 Classification ... 15
5 Measurement performance requirements ... 15
5.1 Q1, Q2, Q3, Q4 value... 15
5.2 Accuracy level and maximum permissible error ... 16
6 General technical requirements ... 18
6.1 Material and structure... 18
6.2 Adjustment and correction ... 19
6.3 Installation conditions ... 19
6.4 Rated working conditions ... 19
6.5 Marking and nameplate ... 20
6.6 Indicating device ... 21
6.7 Verification marks and protective devices ... 24
6.8 Tightness ... 25
6.9 Other requirements for water meters with electronic devices ... 25 6.10 Ancillary device ... 26
7 Control of measuring instrument ... 26
7.1 Verification conditions ... 27
7.2 Verification items ... 29
7.3 Verification method ... 29
7.4 Processing of verification results ... 35
7.5 Verification cycle ... 35
Appendix A Type evaluation outline of cold water meter ... 36
Appendix B Type evaluation check and test list ... 102
Appendix C The role of checking facility ... 119
Appendix D Type evaluation of series water meters ... 124
Appendix E Installation requirements for flow interference test ... 126 Appendix F Reference format of verification record ... 127
Appendix G Verification flow and water consumption reference value of some water meters ... 128
Appendix H Format of verification certificate and verification result notification (inner page) ... 130
Verification regulation of cold water meter
This regulation, referring to the international recommendation OIML R49- 1:2006 (E) "Water meters for measuring drinkable cold and hot water - Part 1: Measurement and technical requirements", OIML R49-2:2006 (E) "Water
meters for measuring drinkable cold water and hot water - Part 2: Test methods", combined with the current situation of the Chinese industry, added and deleted some content.
This regulation is applicable to the type evaluation, first verification, subsequent verification and in-use inspection of cold water meters.
The cold water meter referred to in this regulation is a water meter that measures clean cold water flowing through a closed pipe and has a temperature of T30 or T50, including mechanical water meters, mechanical water meters equipped with electronic devices, water meters based on electromagnetic or electronic principles.
2 Normative references
The following documents are cited in this regulation:
GB/T 778.1-2007 Measurement of water flow in fully charged closed
conduits - Meters for cold potable water and hot water - Part 1: Specifications GB/T 778.2-2007 Measurement of water flow in fully charged closed
conduits - Meters for cold potable water and hot water - Part 2: Installation requirements
GB/T 778.3-2007 Measurement of water flow in fully charged closed
conduits - Meters for cold potable water and hot water - Part 3: Test methods and equipment
OIML R49-1:2006 (E) Water meters intended for the metering of cold potable water and hot water. Part 1: Metrological and technical requirements
OIML R49-1:2006 (E) Water meters intended for the metering of cold potable water and hot water. Part 2: Test methods
OIML D11:2004 (E) General requirements for electronic measuring
of a number of metering chambers of known volume that are successively filled and discharged with water and a mechanism driven by flow.
3.1.12 Velocity meter
A mechanical water meter which is installed in a closed pipeline and composed of moving element driven by the speed of water flow.
3.1.13 Woltmann meter
A velocity meter consisting of a wing rotor rotating around the flow axis. 3.1.14 Single-jet meter and multiple-jet meter
A velocity meter consisting of a turbine rotor rotating around an axis
perpendicular to the water flow. If a single stream impinges on a certain part of the edge of the rotor, it is called a single-jet meter; if multiple streams impinge on a certain part of the edge of the rotor at the same time, it is called a multiple- jet meter.
3.1.15 In-line meter
The water meter which is directly installed in the closed pipeline by using the connecting thread or flange at the end of the water meter.
3.1.16 Combination meter
A water meter composed of a large water meter, a small water meter, a
conversion device; the water flow automatically flows through the small water meter or the large water meter, or flows through both meters at the same time according to the flowrate. The reading of the water meter is given by two independent calculators, or given by a calculator after adding the values on the two water meters.
3.1.17 Concentric meter
A water meter that can be connected to the pipeline with a collecting pipe. At the contact surface, the inlet, outlet and collecting pipe, the water meter is coaxial. The collecting pipe is a special connecting pipe for concentric meters. 3.1.18 Water meters equipped with electronic devices
A water meter equipped with electronic devices to achieve predetermined functions. Water meters with electronic devices include mechanical water meters equipped with electronic devices and water meters based on
electromagnetic or electronic principles. The electronic device includes a flow signal conversion and processing unit, meanwhile it may be added with storage memory devices, presetting devices, price display devices, etc.
The following are not considered to be significant faults:
a) Fault caused by simultaneous and independent causes in the water meter itself or its checking facility;
b) Temporary fault, manifested as an instant indication change that cannot be interpreted, stored or transmitted as a measurement result.
The ability of the water meter to maintain its performance characteristics after a period of use.
3.2.12 Metering conditions
When measuring water volume, the conditions of the water at the measuring point (such as water temperature and water pressure).
3.2.13 First element of an indicating device
The graduated ruler element with verification scale interval as equipped in an indicating device which is composed of several elements.
3.2.14 Verification scale interval
The smallest division of the first element of an indicating device.
3.2.15 Resolution (of an indicating device)
The smallest difference between the indicating values that can be effectively distinguished in the indicating device.
Note: For digital devices, the resolution is the amount of change when the minimum effective number of the indicating device changes by one step.
3.3 Operating conditions
3.3.1 Flowrate Q
The quotient of the actual volume through the water meter and the time used. 3.3.2 Permanent flowrate Q3
Maximum flowrate under rated operating conditions. At this flowrate, the water meter works normally, and the indication error is within the maximum
meter can withstand for a long time without reducing its measurement
3.3.10 Working temperature Tw
The average water temperature of the upstream and downstream pipe sections of the water meter.
3.3.11 Working pressure pw
The average value of the water pressure in the upstream and downstream pipe sections of the water meter.
3.3.12 Pressure loss ??p
At a given flowrate, the pressure drop due to the presence of a water meter in the pipeline.
3.3.13 Nominal size
The nominal value of the diameter of the water meter. It is usually expressed by the number plus the unit of the nominal value of the diameter at the beginning of the capital letter "DN", for example: DN15 mm.
Note: The nominal size is also called the nominal diameter.
3.4 Test conditions
3.4.1 Influence quantity
A physical quantity that is not measured but affects the measurement result. 3.4.2 Influence factor
The influence quantity within the rated working conditions of the water meter specified in this regulation.
The influence quantity whose value is within the limit specified in this regulation but is outside the range of the rated working conditions of the water meter. Note: If the rated working condition does not specify a certain influence quantity, the influence quantity is a disturbance.
3.4.4 Rated operating condition
Given the use conditions of the value range of the influence factor, the error of calculator to calculate the volume of water flowing for a period of time. The measurement sensor of water meter generally adopts mechanical principle, but also can adopt electronic or electromagnetic principle to measure.
The water meter shall include at least three parts: a measurement sensor, a calculator (which may include an adjustment or correction device), an indicating device. Each part can be grouped together or installed at different locations. In order to increase the measurement range, the water meter can be combined with multiple meters into an integral type, such as a combination meter. Water meters can be equipped with auxiliary equipment used to complete
Mechanical water meters equipped with electronic devices (such as electronic remote water meters, IC card water meters, etc.) usually use coding circuits or inductive signaling devices to convert the primary indication or variation of mechanical water meters into electrical signals or other signals.
The specific working principle and structural composition of water meters (such as electromagnetic water meters, ultrasonic water meters, etc.) that are measured by electronic or electromagnetic principles can refer to the flowmeter verification regulations with the same working principle.
4.2.1 According to the working principle and composition structure of water meters, water meters can generally be divided into mechanical water meters and water meters with electronic devices.
4.2.2 Mechanical water meters are divided into velocity meters and volumetric water meters.
4.2.3 Water meters with electronic devices include electronic water meters and mechanical water meters equipped with electronic devices.
Note: In this regulation, water meters whose measurement sensors are based on electric or electronic principles are collectively referred to as electronic water meters, such as electromagnetic water meters and ultrasonic water meters. 5 Measurement performance requirements
5.1 Q1, Q2, Q3, Q4 value
5.1.1 The flow characteristics of the water meter are determined by Q1, Q2, Q3, Q4.
5.2.6 The manufacturer shall indicate whether the water meter can measure reverse flow. If possible, the actual volume during the reverse flow period shall be subtracted from the displayed volume or recorded separately. Both forward flow and reverse flow shall meet the requirements of the maximum permissible error.
Water meters that cannot measure reverse flow shall be able to prevent reverse flow; or otherwise it is able to withstand unexpected reverse flow without causing any degradation or change in forward flow metering performance. 5.2.7 When the temperature and pressure change within the rated working conditions of the water meter, the water meter shall meet the requirements of the maximum permissible error.
5.2.8 When the flow is zero, there shall be no change in the integrated reading of the water meter.
5.2.9 According to the accuracy level of the water meter, the maximum
permissible error of the water meter in use is twice the maximum permissible error in 5.2.1 or 5.2.2.
6 General technical requirements
6.1 Material and structure
6.1.1 The materials used to make the water meter shall have sufficient strength and durability to meet the use requirements of the water meter.
6.1.2 The material of the water meter shall not be adversely affected by the water temperature change within the working temperature range (see 6.4). 6.1.3 All parts of the water meter that contact water shall be made of materials that are generally considered non-toxic, non-polluting, non-biologically active, comply with relevant technical standards.
6.1.4 The manufacturing material of the integral water meter shall be resistant to internal and external corrosion, or be treated with appropriate surface protection.
6.1.5 The indicating device of the water meter shall be protected by a
transparent window, equipped with a suitable meter cover as auxiliary
6.1.6 If condensation may form inside the transparent window of the water meter indicating device, the water meter shall be equipped with a device to eliminate condensation.
6.5 Marking and nameplate
The following information shall be clearly and permanently marked on the water meter enclosure, the dial or nameplate of the indicating device, the non- separable water meter cover, in a centralized or scattered manner.
Note: For the case of a combination meter, the following marks indicate the parameter information of the entire combination meter.
a) Unit of measurement: cubic meter or m3;
b) Accuracy level: If it is not level 2, it shall be marked;
c) Q3 value, Q3/Q1 ratio, Q2/Q1 ratio (when it is not 1.6, it shall be noted); d) The mark and number of the license for manufacturing measuring
Note: Imported measuring instruments shall be marked with the type
approval mark and serial number.
e) Manufacturer's name or trademark;
f) Manufacturing year, month and serial number (as close as possible to the indicating device);
g) Flow direction (marked on both sides of the water meter enclosure, or if the flow direction indicator arrow can be easily seen under any
circumstances, it can also be marked on one side only);
h) Maximum admissible pressure: If it exceeds 1 MPa (for water meters with a diameter of DN ??? 500 mm, if it exceeds 0.6 MPa), it shall be marked;
i) Installation method: If it can only be installed horizontally or vertically, it shall be marked (H stands for horizontal installation, V stands for vertical installation);
j) Temperature level: If it is not T30, it shall be marked;
k) Maximum pressure loss: If it is not 0.063 MPa, it shall be noted;
Note: The pressure loss level can be marked according to GB/T 778.1-2007. For water meters with electronic devices, it shall have additional marks: l) External power supply: Voltage and frequency;
m) Replaceable battery: The latest battery replacement time;
These two colors shall be used for pointers, indicator marks, numbers, dials, or for perforated frames.
For electronic water meters, as long as it is ensured that there is no doubt when distinguishing between the primary indication and other displays (such as decimals for verification and testing), other forms of cubic meters and their multiples and scores can be used. For the requirements of electronic display devices, see A.6.4.6.
6.6.2 Type of indicating device
The indicating device of the water meter shall adopt any of the following types. 22.214.171.124 Type 1 analog device
The volume of water is given by the continuous movement of the following components:
a) One or more pointers that move relative to the graduation scale;
b) One or more circular rulers or drums, each passing an indicator mark. The indication value of each scale division in cubic meters shall be in the form of 10n, where n is a positive integer, a negative integer or zero, thereby establishing a continuous decimal system.
Each scale shall be scaled by cubic meters; or attached with a multiplier (X 0.001; X0.01; X 0.1; X1; X10; X100; X1000, etc.).
The rotation movement of the pointer and the circular ruler shall be clockwise. The linear movement of the pointer or ruler shall be from left to right. The movement of the digital drum indicator shall be upward.
126.96.36.199 Type 2 digital device
The indicated volume is given by a row of adjacent numbers displayed in one or more openings. The carry of the previous digit shall be completed when the value of the adjacent lower digit changes from 9 to 0. The movement of the digital drum indicator shall be upward.
The lowest ten numbers can move continuously, the opening is large enough to read the numbers clearly.
The visible height of the number shall be at least 4 mm.
188.8.131.52 Type 3 combination of analog and digital devices
The volume of water is given in the form of a combination of type 1 and type 2 shall not exceed 0.5 mm.
The division value of the verification scale shall be small enough to ensure the resolution of the water meter: for a level 1 water meter, it shall not exceed 0.25% of the actual volume value for 1.5 h at the minimum flowrate Q1; for a level 2 water meter, it shall not exceed 0.5% of the volume value.
Note: When the first component is displayed continuously, the error of each reading is allowed to not exceed half of the interval of minimum scale grid. When the first element is displayed intermittently, the error of each reading is allowed to be one digit.
When the additional device is used for verification, the maximum error of its reading is not more than 0.25% (for the level 1 meter) or 0.5% (for the level 2 meter) of the test volume; meanwhile it does not affect the normal operation of the indicating device.
184.108.40.206 Combination meter
If the combination meter has two indicating devices, both shall meet the requirements of 220.127.116.11 and 18.104.22.168.
6.7 Verification marks and protective devices
6.7.1 The water meter shall have the primary verification mark attached, so that it can be seen without disassembling the water meter.
6.7.2 The water meter shall be equipped with a protective device that can be sealed, to ensure that before and after the water meter is installed correctly, the water meter and/or adjustment device or correction device cannot be
disassembled or modified without damaging the protective device. For
combination meters, this requirement applies to the large and small water meters.
6.7.3 Electronic seal
22.214.171.124 When the mechanical sealing device cannot prevent the parameters that have an influence on the determination of the measurement results from being accessed, the protective measures shall meet the following requirements: a) Parameter access is only allowed by authorized persons, such as using passwords (keywords) or special equipment (such as keys). The
password shall be changeable.
b) At least the last access intervention shall be recorded. The record shall Water meters with electronic devices shall have a good surface treatment, free of burrs, scratches, cracks, rust, mildew and peeling of the coating.
The displayed numbers shall be eye-catching and tidy; the text symbols and signs indicating the function shall be complete, clear and correct.
The protective glass on the reading device shall...