Decree of the Ministry of Industry and Trade No. 333 / 2000 Coll.
Decree of the Ministry of Industry and Trade laying down requirements for hot water meters marked by EEC mark
Valid
Order
Effective from 21.04.2004
333
DECLARATION
Ministry of Industry and Trade
of 6 September 2000
laying down requirements for hot water water meters marked by the EEC mark
The Ministry of Industry and Trade provides, pursuant to Section 27 of Act No. 505 / 1990 Coll., on Metrology, as amended by Act No. 119 / 2000 Coll., ("the Act ') for the implementation of Sections 6 (2) and 9 (1) of the Act:
This Decree lays down requirements for hot water water meters (hereinafter referred to as "water meters'). For the purposes of this Decree, water is considered to be warm if its temperature is greater than 30 oC but does not exceed 90 oC.
Water meters may be marked with the EEC type-approval mark and the initial EEC verification mark, the graphic form of which is provided for in the specific legislation, (2) only if they meet the requirements set out in the Annex to this Regulation and the fulfilment of which has been verified by the procedures laid down in the specific legislation.2)
This Regulation shall enter into force on the day of the publication of the sectoral annex to the Protocol to the Europe Agreement establishing an association between the Czech Republic, of the one part, and the European Communities and their Member States, of the other part, on conformity assessment and acceptance of industrial products in the Collection of International Treaties, or on the date of the entry into force of the Treaty of Accession of the Czech Republic to the European Union, if that date is earlier.
Minister:
Doc.
Annex to Decree No 333 / 2000 Coll.
Requirements for water meters
1. TERMINOLOGY AND DEFINITIONS
This annex applies only to water meters which operate solely on a mechanical principle These water meters use either volume chambers with movable walls or use the effect of the water speed on the turbomachine rotor (radial or axial turbine). This Annex shall not apply to water meters equipped with electronic components.
1.1. Flow
The flow rate is the volume of water flowing through the meter per unit of time.
1.2. Prolonged volume
The elongated volume is the total volume of water that passed through the water meter over a given period of time.
1.3 Maximum flow rate (Qmax)
The maximum Qmax flow rate is the highest flow rate in which the water meter must be able to operate after a limited time interval without damage and without exceeding the maximum permissible error and the maximum permissible pressure loss.
1.4 Nominal flow rate (Qn)
The nominal flow rate Qn is equal to half of the maximum flow rate Qmax. This flow rate is expressed in cubic metres per hour and is used to indicate the water meter.
At the nominal flow rate Qn, the water meter shall be able to operate in normal use, i.e. under continuous and interrupted operating conditions without exceeding the maximum permissible errors.
1.5 Minimum flow rate (Qmin)
The minimum Qmin flow rate is the flow rate above which the maximum permissible error cannot be exceeded and which is fixed as a function of Qn.
1.6 Flow range
The flow range of the water meter is limited by the maximum and minimum flow rates of Qmax and Qmin. This range is divided into two areas, called upper and lower, with various maximum permissible errors.
1.7 Transition flow (Qt)
The transition flow rate Qt is the flow rate that separates the upper and lower flow ranges and in which the maximum permissible error changes incontinuously.
1.8 Maximum holiday error
The maximum permissible error is the greatest possible error of the water meter authorised for EEC type-approval and for the initial EEC verification under this Regulation.
1.9 Pressure loss
Pressure loss means loss which is caused by the presence of a water meter in the pipe.
2. METROLOGICAL PROPERTIES
2.1 Maximum permissible errors
The maximum permissible error in the lower range from Qmin (inclusive) to Qt (excluding) is ± 5%.
The maximum permitted error in the upper range from Qt (inclusive) to Qmax (inclusive) is ± 3%.
2.2 Metrological classes
Water meters are divided according to the above defined values Qmin and Qt into four metrological classes listed in the table below:
| Třídy | Qn | ||
|---|---|---|---|
| < 15 m3/h | ≥ 15 m3/h | ||
| Třída A | Hodnota Qmin | 0,04 Qn | 0,08 Qn |
| Hodnota Qt | 0,10 Qn | 0,20 Qn | |
| Třída B | Hodnota Qmin | 0,02 Qn | 0,04 Qa |
| Hodnota Qt | 0,08 Qn | 0,15 Qn | |
| Třída C | Hodnota Qmin | 0.01 Qa | 0.02 Qa |
| Hodnota Qt | 0.06 Qn | 0.10 Qn | |
| Třída D | Hodnota Qmin | 0.01 Qa | |
| Hodnota Qt | 0.015 Qn | ||
3. TECHNOLOGICAL PROPERTIES
3.1. Construction - General provisions
The gauge shall be so designed that, under normal conditions of use:
(a) provide long-term services and guarantee resistance to fraudulent manipulation;
(b) comply with the provisions of this Decree.
Where water meters may be exposed to an accidental change in the direction of flow, they shall be able to withstand this change without damage and without adverse influence on their metrological properties, while recording this reverse flow.
3.2. Materials
The water meter shall be made of strength and stability materials which correspond to the purpose for which it will be used. The water-meter shall be made entirely of materials resistant to internal and normal external corrosion and, if necessary, shall be provided with appropriate coating. Changes in water temperature between 0 and 110 ° C shall not adversely affect the materials used for the production of the water meter.
3.3 Sealing - pressure impermeability and temperature resistance
The water-meter shall be able to withstand a continuous water temperature of 90 ° C and a continuous pressure for which it has been designed and which is called maximum operating pressure for an unlimited period of time, while maintaining the correct function, without release, leakage through walls and permanent deformation. The minimum value of this pressure is 1000 kPa (10 bar).
3.4 Pressure loss
The value of the pressure loss shall be collected during the EEC type-approval examination; This value shall not exceed 25 kPa (0,25 bar) at nominal flow rate and 100 kPa (1 bar) at maximum flow rate.
On the basis of the test results, the water meters shall be classified into four groups according to whether their pressure loss at maximum flow rate exceeds one of the following values: 100; 60; 30 and 10 kPa (1,0; 0,6; 0,3 and 0,1) bar. The relevance of the water-meter to one of these groups shall be indicated on the EEC type-approval certificate.
3.5 Indicator
The indication device shall allow for reliable, easy and unambiguous reading of the volume of measured water, expressed in cubic metres, by means of a simple and easy-to-understand grouping of its components. This volume is given by one of the following options:
(a) by the position of one or more indicators on circular scales,
(b) displaying a series of consecutive digits in one or more openings;
(c) a combination of these two systems.
The cubic meter and its multiples are shown in black and the parts of the cubic meter are in red.
The optical height of the digits shall not be less than 4 mm.
On digital indicators of types (b) and (c)), the movement of all digits vertically upwards shall be visible. The movement of any digital unit shall be completed when the digits of the nearest lower decade change from 9 to 0; the cylinder representing the smallest valid digit may move continuously for type (c). The whole number of cubic metres shall be clearly marked.
Indicators with indicators of types (a) and (c) shall be rotated clockwise. The value for each section of the scale in cubic metres shall be expressed as 10n, where n is a positive or negative integer or zero, thereby creating a system of consecutive decades. Data shall be displayed near each part of the scale, such as:
| × 1000 | × 100 | × 10 | × 1 | × 0,1 | × 0,01 | × 0,001. |
In both cases (numerical and numerical indicators):
- the symbol of the unit m3 must be displayed either on the code list or in the immediate vicinity of the digital indication,
- the fastest rotating and visually readable numbered element ("control element") shall move continuously; His piece is known as the scale verification piece. The control element may be permanent or created by temporarily adding removable parts. These parts shall not have a significant influence on the metrological characteristics of the water meter.
The length of the scale verification panel shall not be less than 1 mm and shall not be greater than 5 mm. The scale shall include:
• either marks of the same width which are not more than one quarter of the distance between the axes of the two adjacent marks which differ only in length;
• or contrast strips of a constant width equal to the length of the scale verification panel.
3.6 Number of digits and value of scale verification panel
The indicator device shall be able to record the volume, expressed in cubic metres, of at least 1,999 hours of operation at nominal flow rate without returning to zero.
The value of the scale verification panel shall be 1 × 10n or 2 × 10n or 5 × 10n. This size shall be small enough during the verification to ensure that the accuracy of the measurements is not greater than 0,5% (a likely reading error of not more than half the length of the smallest part of the scale is taken into account) and that the minimum flow rate does not exceed 1 1 / 2 hours.
It is possible to add additional equipment (starfish, disc with reference mark, etc.) to show the movement of the measuring device before it is clearly visible on the indicator device.
3.7 A control device
The water meter may be equipped with a justice device by which the relationship between the indicated volume and the volume that has actually flowed can be changed. This device is mandatory for water meters which use the effect of water speed on the turbomachine rotor.
3.8 Acceleration equipment
The use of an accelerator device to increase the speed of the water meter below Qmin is prohibited.
3.9 Additional equipment
The water meter may contain an impulse generating device provided that such equipment does not adversely affect its metrological characteristics.
The EEC type-approval certificate may allow the addition of specially fixed or removable devices allowing automatic verification of the water meter.
4. MARKS AND NAMES
4.1 Identification
For all water meters, it is mandatory that they carry the following information in legible and indelible form, either separately or grouped on the water meter housing, on the indicator code list or on the information plate:
(a) the name of the manufacturer or the trade name or trade mark;
(b) metrological class and nominal flow rate Qn in m3 / h;
(c) the year of manufacture and the production number;
(d) one or two arrows indicating the direction of flow;
(e) the EEC type-approval mark,
(f) maximum operating pressure in bars if more than 1000 kPa (10 bar);
(g) maximum operating temperature in ° C;
(h) the letter "V" or "H" if the water meter can function correctly in a vertical (V) or horizontal (H) position.
4.2 Location of EEC initial verification marks
For EEC initial verification marks, a space visible without dismantling of the water meter must be reserved on the base part (mostly on the water meter housing).
4.3 Plumbing
The water meter shall be equipped with protective devices that can be sealed in such a way as to ensure that neither the water meter alone nor its juicing device can be removed nor modified before and after the correct installation of the water meter.
5 EEC TYPE-APPROVAL
5.1. Procedure
EEC type-approval shall be carried out in accordance with a separate legislative act (3).
5.2. Type examination
If it has been established from the attached documentation that the type complies with the provisions of this Decree, then laboratory tests shall be carried out on a number of instruments under the following conditions:
5.2.1. Number of water meters tested
The number of water meters to be submitted by the manufacturer is shown in the table below:
| Jmenovitý průtok Qn, m3/h | Počet vodoměrů |
|---|---|
| Qn < 1,5 | 10 |
| 1,5 ≤ Qn < 15 | 3 |
| Qn ≥ 15 | 2 |
Depending on the course of the tests, the authorised authority may:
• decide not to conduct tests with all water meters submitted; or
• request additional water meters from the manufacturer to allow the tests to continue.
5.2.2. Pressure
For the metrological tests referred to in paragraph 5.2.4, the pressure at the outlet of the water meter shall be high enough to avoid cavitation.
5.2.3. Test equipment
In general, water meters shall be tested individually and in all cases in such a way as to accurately demonstrate the individual characteristics of each of them.
The Czech Metrology Institute or Authorised Metrology Centre must take all necessary steps to ensure that the relative inaccuracy when measuring the volume of water supplied does not exceed 0,3%, including the inclusion of various causes of error caused by installation.
The maximum permissible inaccuracy is 5% for pressure measurement and 2,5% for pressure loss measurement.
During each test, the relative change in flow shall not exceed 2,5% between Qmin and Qt and 5% between Qt and Qmax.
The maximum allowed temperature is 1 ° C.
The test equipment must be approved by the Czech Metrology Institute regardless of where the tests are carried out.
5.2.4. Tests
5.2.4.1. Test procedure
The tests shall include the following activities to be carried out in the following order:
(a) pressure leak test;
(b) determination of the error curves depending on the flow through the detection of the potential impact of pressure, temperature and including the normal installation conditions specified by the manufacturer for this type of water meter (direct sections of the upstream and downstream pipelines, narrowing, obstacles, etc.),
(c) the determination of the pressure loss;
(d) an accelerated long-term stability test;
(e) a heat impact resistance test for water meters with a nominal Qn flow rate not greater than 10 m3 / h.
5.2.4.2. Description of tests
The tests shall be carried out as follows.
• The pressure leak test shall be carried out at (85 ± 5) ° C in two parts:
(a) each water-meter must withstand a pressure equal to 1.6 times the maximum operating pressure applied for 15 minutes, without discharging or leaking through the walls (see paragraph 4.1 (f));
(b) each water-meter shall withstand a pressure equal to twice the maximum operating pressure applied for one minute without damaging or blocking (see paragraph 4.1 (f)).
• The results of the error and pressure loss tests must provide a sufficient number of points in order to reliably draw the curves across the whole range.
• Accelerated long-term stability tests are carried out as shown in the table below:
| Jmenovitý průtok vodoměru | Zkušební průtok a teplota | Druh zkoušky | Počet přerušení | Doba trvání přestávek | Doba činnosti při zkušebním průtoku | Doba trvání spuštění a zastavení (sekundy) |
|---|---|---|---|---|---|---|
| Qn ≤ 10 m3/h | Qn (50 ± 5) °C | Nespojitá | 100 000 | 15 s | 15 s | 0,15 (Qn),(1) minimálně 1 s |
| Qmax (85 ± 5) °C | Spojitá | 100 h | ||||
| Qn > 10 m3/h | Qn (50 ± 5) °C | Spojitá | 500 h | |||
| Vmax (85 ±5)°C | Spojitá | 200 h |
(1) (Qn) is a number equal to the value of Qn expressed in m3 / h.
The measurement errors shall be determined before the first test and after each series of tests; the minimum requirement is to be determined at the following flows:
| Qmin | Qt | 0,5 Qn | Qmax |
In each test, the volume of water flowing through the water meter shall be large enough to turn the indicator or cylinder on the verification scale by one or more full turns and to avoid the effect of the periodic error of data.
The temperature test shall contain 25 cycles, which shall be carried out as follows:
| Teplota vody | Průtok | Doba trvání |
|---|---|---|
| (85 ± 5) °C | Qmax | 8 minut |
| - | 0 | 1 až 2 minuty |
| Studená voda | Qmax | 8 minut |
| - | 0 | 1 až 2 minuty |
5.2.5. Conditions for EEC type-approval
The water-meter type is approved if:
(a) complies with the administrative, technical and metrological requirements of this Order and its Annex;
(b) the tests (a), (b) and (c) referred to in paragraph 5.2.4.1 show that it corresponds, in terms of metrological and technological characteristics, to Parts II and III of this Annex;
(c) no change in relation to the initial curve greater than 1,5% between Qt and Qmax or more than 3% between Qmin and Qt shall be detected after completion of each accelerated durability test and after each heat impact test.
5.3. EEC type-approval certificate
The EEC type-approval certificate may allow the possibility of conducting a cold water precision test on initial verification.
This option is only allowed if, during the EEC type-approval examination, it has enabled the examination of the equivalence relationship between hot and cold water to perform a cold water precision test and if this test has shown that the water-meter which has passed this test also complies with the maximum permissible errors referred to in point 2.1.
In this case, the EEC type-approval certificate shall contain a description of this test and the relevant requirements, in particular those relating to permitted errors and test flows.
6. FIRST EEC VERIFICATION
The initial EEC verification of watermeters shall be carried out in accordance with a specific legislation2).
6.1. Verification procedure
Initial verification must be carried out on a site approved by the Czech Metrology Institute.
The layout of the premises and test facilities shall be such that the verification can be carried out under safe, reliable conditions and without any time loss for the persons responsible for these tests. The requirements of paragraph 5.2.3 shall be met, except for the temperature requirements of water meters for which cold water tests are carried out in accordance with the provisions which may appear on the EEC type-approval certificate. In the test centre, arrangements may be made to allow water meters to be tested in series. However, the output pressure of all water meters shall always be sufficient to avoid cavitation; Special measures may be taken to prevent interactions between water meters.
The complete apparatus may contain automatic devices, bypass valves, flow limiters, etc., provided that each test circuit between verified water meters and control tanks is clearly defined and that the internal pressure tightness of these circuits can be checked at any time.
Any type of water supply system may be used, but if several test circuits operate in parallel, there shall be no interaction incompatible with the requirements of paragraph 5.2.3.
If the control tank is divided into several chambers, then the separation walls shall be strong enough to ensure that the volume of any chamber does not change by more than 0,2% depending on whether the adjacent chambers are full or empty.
6.2. Test procedure
Watermeters shall conform to the type approved.
The initial EEC verification shall include tests of pressure tightness and accuracy.
6.2.1 Pressure leak test
The pressure leak test may be carried out with cold water. This test shall be performed for one minute at 1.6 times the maximum operating pressure. During this test no release or leakage shall occur through the walls of the water meter.
6.2.2. Precision test
6.2.2.1. Hot water precision test
The accuracy test shall normally be carried out with hot water at a temperature (50 ± 5) ° C at at least three flows:
(a) between 0,9 Qmax and Qmax,
(b) between Qt and 1,1 Qt,
(c) between Qmin and 1,1 Qmin ·
During this test the water-meter shall comply with the maximum permissible errors specified in paragraph 2.1.
If it is found that all errors lie in one direction, then the water meter must be set so that all errors do not exceed half the maximum permissible error.
6.2.2.2. Cold water precision test
The accuracy test may be carried out with cold water if this is provided for in the EEC type-approval certificate. In this case the test shall be carried out according to the procedures specified in the relevant certificate.
1) Decree No. 262 / 2000 Coll., which ensures uniformity and correctness of meters and measurements.
2) Decree No. 332 / 2000 Coll., laying down certain procedures for the approval and verification of certain EEC-marked measuring instruments.
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Regulation Information
| Citation | Decree of the Ministry of Industry and Trade No. 333 / 2000 Coll., laying down requirements for hot water meters marked by EEC mark |
|---|---|
| Regulation Type | Order |
| Author | - |
| Collection | Code of Laws |
| Date of Promulgation | 26.09.2000 |
|---|---|
| Effective from | 21.04.2004 |
| Effective until | - |
| Status | Valid |
The regulation text is for informational purposes only.
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