The Requirements For Water Meters For Cold Water Called The Eec

Original Language Title: požadavky na vodoměry na studenou vodu označované značkou EHS

Read the untranslated law here: https://portal.gov.cz/app/zakony/download?idBiblio=49706&nr=334~2F2000~20Sb.&ft=txt

334/2000 Sb.



DECREE



The Ministry of industry and trade



of 6 May 1999. September 2000,



laying down the requirements for water meters for cold water called

the EEC



Change: 260/2003 Coll.



The Ministry of industry and trade shall determine in accordance with section 27 of Act No. 506/1990

Coll. on metrology, as amended by Act No. 121/2000 Coll. (hereinafter the "Act")

for the implementation of § 6 (1). 2 and § 9 para. 1 of the Act:



§ 1



This Decree lays down the requirements for water meters for cold potable water (hereinafter referred to as

"meters"). For the purpose of this order is deemed to be cold water

If the temperature in the range from 0 ° C to 30 ° c.



§ 2



Water meters can be instead of marking the official marks laid down

special legal regulation ^ 1) marked by an EEC type-approval, and

the initial EEC verification, whose graphic design provides for a specific legal

prescription, ^ 2) only if they meet the requirements set out in the annex to this

the Decree, and that it was verified the procedures laid down in a special

legislation. ^ 2)



§ 3



This Decree shall take effect on the date of publication of the sectoral annex for

the measuring instrument to the Protocol to the Europe Agreement establishing an association between the

The Czech Republic on the one hand, 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 entry

the Treaty of accession of the Czech Republic to the European Union entered into force,

If the day earlier.



Minister:



doc. Ing. Gregr, r.



XIII.



The meters requirements



1.



TERMINOLOGY AND DEFINITIONS



This annex applies only to cold-water meters based on direct mechanical

the principle, which is based on the use of volumetric Chambers with moving

walls or on the influence of the velocity of the water on the speed of rotation of the moving

(radial or axial turbine).



1.1 Flow



Flow is the volume of water passing through the meter per unit of time and

This volume is expressed in cubic metres or litres and the time in

hours, minutes, or seconds.



1.2 volume delivered



Volume delivered is the total volume of water that has passed through the meter for a given

period of time.



1.3 Maximum flowrate (Qmax)



Maximum flowrate, Qmax, is the highest flowrate at which the meter can

function over limited periods without damage, and without exceeding the

the maximum permissible errors and the maximum permissible value for loss of pressure.



1.4. Nominal flowrate (Qn)



Nominal flow Qn, is equal to half the maximum flowrate, Qmax. This

the flow rate is expressed in cubic metres per hour and is used for

indication of the meter.



At the nominal flowrate, Qn, the meter must be able to function in normal

use, i.e.,. for continuous and intermittent operating conditions, without

you have exceeded the maximum permissible errors.



1.5 the minimum flowrate (Qmin)



The minimum flow Qmin is the flowrate above which the value of the meter shall not

exceed the maximum permissible errors and that is fixed as

a function of qn.



1.6. Flowrate range



The flowrate range of the meter is bounded by the maximum and minimum flowrates,

Qmax and Qmin. This range is divided into two regions, known as

the top and bottom, with different maximum permissible errors.



1.7. Transitional flowrate (Qt)



The transitional flowrate, Qt, is the flowrate which divides the upper and lower range

the flow and in which regions the maximum permissible error.



1.8. Maximum permissible error



The maximum permissible error is the error of the meter allowed for

EEC type-approval and the initial EEC verification pursuant to this order.



1.9. Pressure loss



Loss of pressure means the loss which is caused by the presence of a water meter

in the pipeline.



2.



METROLOGICAL CHARACTERISTICS



2.1. Maximum permissible errors



The maximum error permitted in the lower range from Qmin inclusive to Qt

(except) is +/-5%.



The maximum permissible error in the upper region from Qt inclusive to Qmax

(including) is +/-2%.



2.2. Metrological classes



Water meters are divided, according to the above values of Qmin and Qt defined into three

metrological classes in the following table:



+--------------------------+-------------------------------+

| Class | Qn |

| +-----------------+-------------+

| | < 15 m3/h | > = 15 m3/h |

+--------------------------+-----------------+-------------+

| Class A | | |

| Value: Qmin | 0.04 Qn | 0.08 Qn |

| Value: Qt | 0.10 Qn | 0.30 Qn |

+--------------------------+-----------------+-------------+

| Class B | | |

| Value: Qmin | 0.02 Qn | 0.03 Qn |

| Value: Qt | 0.08 Qn | 0.20 Qn |

+--------------------------+-----------------+-------------+

| Class C | | |

| Value: Qmin | 0.01 Qn | 0.006 Qn |

| Value: Qt | 0.015 Qn | 0.015 Qn |

+--------------------------+-----------------+-------------+



3.



TECHNOLOGICAL PROPERTIES



3.1 Construction-General provisions



The meter must be constructed in such a way as to:



(a) give long service and guarantee proof against fraud

handling,



(b) under normal conditions of use, conform with the provisions of this Ordinance.



Where meters may be subjected to an accidental reversal of flow,

must be able to change this without damage, and without changing their

metrological properties, and at the same time it must reverse the flow

record.



3.2 Materials



The meter must be made of materials of adequate strength and stability, which

correspond to the purpose for which it will be used. The meter must be completely

made of materials that are resistant to internal and normal external

corrosion, and, if necessary, must be equipped with a suitable surface treatment.

Water temperature variations within the working temperature range must not adversely

affect the materials used for the manufacture of the meter.



3.3. pressure tightness-proofness



The meter must be able to indefinitely, while maintaining the correct

function, no leaks, leaking walls and permanent deformation

to withstand the constant pressure of water, for which it is designed, and which is called the

the maximum operating pressure. The minimum value for this pressure is 1000 kPa (10

bar).



3.4 pressure loss



Pressure drop across the meter is determined during the tests for the EEC

type-approval, and shall not exceed 25 kPa (0.25 bar) at nominal

the flow and 100 kPa (1 bar) at the maximum flowrate.



Based on the results of tests with water meters shall be placed into one of four groups

with the following maximum values for pressure loss: 100; 60; 30, and 10

kPa (1.0; 0.6; 0.3 and 0.1 bar). The appropriate value must be indicated in the

EEC type-approval certificate.



3.5 the indicating device



The indicating device must make it through a simple and

juxtaposition of its various parts, reliable, easy and

unambiguous reading of the volume of water measured, expressed in meters

cubic. This volume is given one of the following options:



and) by the position of one or more pointers on circular scales,



(b)) by displaying a series of consecutive digits in one or more apertures,



(c)) the combination of these two systems.



The cubic metre and its multiples must be displayed with black paint, parts

cubic meter must be displayed in red.



Optical height of the figures must not be less than 4 mm.



On digital indicators type b), and (c)) visible displacement of all must be

numbers vertically upwards. The offset of any numerical units must be

completed at the time when the next lower decade changes from 9 to

0; the roller showing the least significant digits, type c)

move continuously. Complete the number of cubic metres must be clearly

marked.



Indicators with pointers of type a) and (c)) must rotate in the direction of

clockwise. The value of each Division of the scale in metres

cubic 10En must be expressed as, where n is a positive or negative

whole number or zero, thereby establishing a system of consecutive decades. In

near each part of the scale shall bear the following markings:

x 1000 x 100 x 10 x 1 x x 0.1 0.01 x 0.001.



In both cases (dial and digital indicators):



-the unit symbol m3 must be shown either on the dial or in the

the immediate vicinity of the digital indication,



-the fastest-spinning and visually readable graduated element (

"the control element") must move continuously; his piece is known as

verification scale interval. Control element may be permanent or may be

created temporarily by adding detachable parts. These parts must not have

a significant influence on the metrological characteristics of the meter.



The length of the verification scale interval shall not be less than 1 mm and not

greater than 5 mm. Scale must contain:



and tags) of the same width, which is not more than one quarter of the

the distance between the axes of two adjacent marks that differ only in their

length, or



(b)) of contrasting bands of a constant width equal to the length of one of the interval

the scale.



3.6 number of digits and the value of the verification scale interval



The indicating device must be able to record without returning to zero

the volume in cubic meters, which is equivalent to at least 1 999

hours of operation at the nominal flow rate.




The value of the verification scale interval must be 1 x 10En or

2 x or 5 x 10En 10En. When the value of the authentication must be sufficiently

small, in order to ensure that the measurement inaccuracy of not more than 0.5% (as of

consideration is allowing for a possible reading error of not more than half the length of the

the smallest scale interval) and that at the minimum flowrate did not last

test more than 1 1/2 hours.



It is possible to add a supplementary device (Star, disc with a reference

mark, etc.), in order to show the movement of the measuring instrument before

It will be clearly visible on the indicating device.



3.7 adjustment device



The meter may be equipped with an adjustment device with which it is possible to

to change the ratio between the volume indicated and the volume actually

passed. This device is compulsory for meters which make use

the action of the velocity of the water on the rotation of the moving parts.



3.8. Accelerating device



Use of an accelerating device for increasing the speed of the meter when you

flow rates below Qmin is prohibited.



4.



MARKS AND INSCRIPTIONS



4.1 Identification inscriptions



For all water meters is required to bear in legible and indelible

the form of the following information, either separately or grouped together on the

the meter casing, the indicator on the dial or on the information plate:



and the name of the manufacturer) or business name or the trade mark,



(b)) the metrological class and nominal flowrate Qn in m3/h,



c) year of manufacture and the serial number,



(d)) one or two arrows showing the direction of flow,



(e)) EEC type-approval mark,



(f)) the maximum operating pressure in bar, if greater than 1 000 kPa (10

bar),



(g)) the letter "V" or "H" If the meter can operate properly only

in the vertical (V) or horizontal (H) position.



4.2 location of the initial EEC verification marks



To affix the EEC verification mark must be the essential part (normally

on the meter casing) instead, which is visible without disassembly

the water meter.



4.3 Sealing



The meter must be equipped with means of protection to seal

in such a way as to ensure that the correct before installing the meter

and the meter will not be possible for her or its adjustment device without damage

protective equipment to remove or change.



5.



EEC TYPE-APPROVAL



5.1. procedure



EEC type-approval shall be carried out under a special legal

prescription ^ 2).



5.2 type-examination



When it has been ascertained from the application file that the pattern conforms to the

the provisions of this Ordinance, then the laboratory tests must be carried out on

a number of instruments under the following conditions:



5.2.1 number of meters to be tested



Number of meters to be submitted by the manufacturer is as shown in the following

table:

+--------------------------------+-------------------+

| Nominal flow Qn, m3/h | The number of water meters |

+--------------------------------+-------------------+

| Qn 10 | | | | | | |

| | 2 Qn | continuous | | | 200 h | |

+---------+--------+---------+---------+---------+---------+-----------+

(*) (Qn) is a number equal to the value of Qn, expressed in m3/h.

------------------------------------------------------------------------



Before the first test and after each series of tests shall determine the error

measurement; the minimum requirement is to be determined at the following

the following flow rates:



Qmin, Qt Qn 0.5 0.3 Qn 1 Qn 2 Qn



During each test, the volume of water must be flowing through the meter

large enough to turn the pointer or roller on the verification

the scale of one or more complete revolutions and to eliminate the effects of

cyclic distortion.



5.2.5. Conditions for EEC type-approval



Type of meter is approved if it meets the following conditions:



a) corresponds to the administrative, technical and metrological provisions of this

the Ordinance and its annex,



b) tests and), b) and (c)) under point 5.2.4 show that matches in terms of

metrological and technological characteristics of parts II and III of this

of the annex,



c) after each accelerated endurance test:



1. no change was observed in relation to the initial curve greater than

1.5% between Qt and Qmax or greater than 3% between Qmin and Qt,



2. the maximum error of the meter between Qmin and Qt is +/-6% between Qt and Qmax

is +/-2.5%.



6.



THE INITIAL EEC VERIFICATION



This verification shall be carried out in a place approved by the Czech metrology

Institute. Layout of the premises and equipment must be such that the

verification may be carried out in safe, reliable conditions and without

loss of time for the persons who are responsible for these tests. Must be

comply with the provisions of point 5.2.3, but if it is desirable,

water meters to be tested in series. If this method is used, then the output

the pressure of all the meters must be sufficient; in order to avoid cavitation,

Special measures may be taken to prevent interference

between meters.



The complete unit may include automatic devices, by-pass

valves, flow limiters, etc. assuming that each test circuit

among the verified meters and control tanks is clearly defined and

that is possible at any time to check the internal pressure tightness of these

circuits.



You can use any type of water supply system, but if

several test circuits are operated in parallel, then between them

There are no interference incompatible with the provisions of section

5.2.3.



If a control tank is divided into several chambers, the separating

the walls must be sufficiently rigid to ensure that the volume of any

the Chamber does not vary by more than ± 0.2% according to whether the adjacent

Chambers are full or empty.



Verification of the accuracy test at least includes three

the following flow rates:



and) between 0.9 Qmax and Qmax,



(b)) between Qt and Qt, 1.1



c) between Qmin and 1.1 Qmin.



The first of these tests involves the determination of pressure losses, which should

be less than the value indicated in the EEC pattern approval certificate.




The maximum permissible errors are specified in section 2.1.



In each test, the quantity of water must be flowing through the meter is sufficiently

big, to turn a pointer or roller on the verification scale through one

or more complete revolutions and to limit the effects of cyclic distortion.



If it is found that all the errors lie in one direction, then the water meter

You must set up so that all errors do not exceed half of the maximum

permissible error.



1) Decree No. 262/2000 Coll., which ensures consistency and accuracy

measuring instruments and measurements.



2) Decree No. 332/2000 Coll., laying down some of the procedures in the

type-approval and verification of measuring instruments, called marker set

EEC.