Legal Metrology Act, 2014 (Act No. 9 of 2014)RegulationsLegal Metrology Regulations, 2017Part XI : Measuring instruments and containers used for prescribed purposes108. Liquid meters and liquid meter systems |
| (1) |
| (a) | A meter must be— |
| (i) | so designed and constructed as to measure correctly the volume of the liquid or liquids for which it is to be used; |
| (ii) | made of such materials as will effectively preclude inaccurate measurement due to any corrosive or other injurious property of the liquid being measured; |
| (iii) | so constructed and installed that there is no leakage at any point of the installation; |
| (iv) | provided with a means for accurately taking the temperature of the liquid stream at the meter in the case of a fixed installation for wholesale delivery; |
| (v) | provided with a suitable device for adjusting the relation between the indicated and actual volume of liquid passing through it, or suitable change gears must be provided for such purpose: Provided that a bypass arrangement must not be used as an adjusting device; |
| (vi) | provided with a means for sealing the calibration adjusting mechanism, the registering mechanism and any working parts of a meter to prevent unauthorised access (tampering) thereto. |
| (b) |
| (i) | A meter may be provided with a manually operated or automatic temperature compensating device which adjusts the measuring or recording mechanism so as to indicate the volume of the measured quantity of liquid at 20°C: Provided that, where a manually operated compensator is used, an accurate Celsius thermometer must be fitted in the liquid stream immediately before the meter inlet opening, and provided further that, where an automatic compensator is used, a means for taking the temperature at such point must be provided. |
| (ii) | The temperature range of a compensating device referred to in subparagraph (i) and the coefficient of expansion or other data on which the compensation is based must be clearly and indelibly marked on the outside of the temperature compensating device. |
| (2) | A meter must be equipped with— |
| (a) | a means for automatically breaking the syphon action in the delivery piping or hose in the case where the delivery piping or hose is not detachable from the meter and where the delivery piping or hose is arranged to empty by gravitation at the end of a delivery; |
| (b) | a device of suitable size, design and construction, fitted as closely as possible to the meter on the inlet side thereof, for the purpose of separating and eliminating any air or vapour from the liquid stream before the liquid enters the meter, such device being provided with effective means to allow air or vapour to escape therefrom or to by-pass the meter, as may be required, or for the purpose of stopping the flow of liquid and air or vapour to the meter in the event that air or vapour is present in the liquid stream: Provided that, where the viscosity or other physical property of a liquid renders such separating or flow-stopping device ineffective, other suitable means for preventing the entry of air or vapour into the meter must be provided; |
| (c) | a suitable filter or strainer, fitted in the liquid stream on the inlet side of the meter to prevent foreign particles from entering the meter; |
| (d) | any other ancillary device that may be required by the National Regulator to ensure the accuracy of the meter under all conditions which may arise during its use; |
| (e) | a plate, permanently attached to the meter unless it is a meter incorporated in a lubricating oil dispenser or in a liquid fuel dispenser, on which the maximum and minimum rate of flow for which the meter is type approved is marked in terms of litres per minute (L / min); and |
| (f) | a plate, permanently attached or sealed to the meter, on which the product or products for which the meter may be used is marked in addition to any other information required by the National Regulator. |
| (3) | The figures on all meter dials, counters and recorders must— |
| (a) | be clearly legible; |
| (b) | in the case of any re-set type of counter, be in proper alignment when the counter is set to zero: Provided that, where the figures are re-set in the forward or increasing direction, they must be obscured during the entire re-setting operation unless the re-setting operation, once started, cannot be stopped until the zero indication is reached. |
| (4) |
| (a) | Where a meter is not provided with a non-return check valve, the registration mechanism of a recording device must not be reversible by reversing the direction of liquid flow through the meter. |
| (b) | A meter must be installed in such a manner as to provide ready and convenient access to the position of the verification mark and to the protective mark arrangements. |
| (c) |
| (i) | Where a meter is provided with a flexible delivery hose and the control valve is situated at the outlet thereof, such hose must be of a non-expansible type and a spring loaded check and non-return valve must be provided downstream of the control valve to ensure that the hose remains filled, unless otherwise approved by the National Regulator for a special purpose. |
| (ii) | Any hose, which is required to be drained after a delivery must be so fitted as to allow complete discharge of liquid. |
| (d) | The ratio between the maximum and minimum type approved flowrates of the measuring system must be at least 5. The measuring system must be designed so that the flowrate is between the minimum type approved flowrate and the maximum type approved flowrate, except at the beginning and at the end of the measurement or during interruptions. |
| (e) |
| (i) | The maximum flow rate of a meter must be limited during use to within any margins in the range between the marked maximum and the prescribed minimum flow rates if such limitation is required for the purpose of ensuring maximum efficiency of air or vapour elimination and accuracy of measurement which could be influenced by the physical properties of the liquid being measured or by any other adverse condition arising during its use. |
| (ii) | The limiting of the flow rate provided for in subparagraph (i) must be effected by such means and in such manner as may be required by the National Regulator. |
| (iii) | Any orifice plate or flow rate controller required in terms of subparagraph (i) and (ii) must, unless otherwise approved by the National Regulator, be situated on the outlet side of the meter and means for sealing must be provided for any such device which is adjustable or can be tampered with. |
| (f) | Instruments for auxiliary measurements such as thermometers and hydrometers must comply with the relevant requirements in SANS 1698. |
| (5) | A liquid meter system used for transferring of liquid where the piping both upstream and downstream of the meter is normally filled with the liquid must be provided with means for delivering the measured liquid into or through a verification device used as a standard. |
| (6) |
| (a) | Liquid meters and liquid meter systems must be verified in-situ unless otherwise permitted by the National Regulator. |
| (b) | The liquid which is normally measured by a liquid meter must be used for testing the meter in the case where the meter is used for a single product. |
| (c) | In the case where a liquid meter is not fitted with a temperature compensator it may be used for delivering more than one product, if it has been verified with the liquid having the higher viscosity according to following— |
| (i) | verified with diesel and used for diesel and power paraffin; |
| (ii) | verified with power paraffin and used for power paraffin and all grades of petrol; or |
| (iii) | verified with any grade of petrol and used for all grades of petrol and similar liquids such as benzene which is not of a higher viscosity than petrol. |
| (d) | After the liquid meter system has been thoroughly flushed, a liquid meter must be tested for accuracy and constancy by direct comparison with a certified measure of volume, or by other means approved by the National Regulator— |
| (i) | at its maximum rate of flow or at the maximum rate of which the liquid meter system is capable, provided that the latter rate must not exceed the maximum flow rate marked on the meter; |
| (ii) | at one-half of its maximum rate of flow; and |
| (iii) | at one-fifth of its maximum rate of flow or at the minimum flow rate where this is less than one-fifth of the maximum and is marked on the liquid meter. |
| (e) | For the purpose of the tests prescribed in paragraph (d), the reduced flow rates must be affected by manipulation of the discharge control valve or by other suitable means. |
| (f) | For tests prescribed in paragraph (d)(i), (ii) and (iii), the measurement by the liquid meter must be correct, whether the reset counter, where fitted, is or is not reset to zero before a test is commenced. |
| (g) | Special tests may be prescribed by the National Regulator to establish— |
| (i) | the efficiency of any ancillary equipment used with the liquid meter system; and |
| (ii) | the effect on the accuracy of the liquid meter of any possible condition which may arise during the use of the liquid meter system as a result of the peculiarities of the system as a whole. |
| (h) | Any inefficiency or adverse effect revealed during the tests referred to in paragraph (g) must not affect the accuracy of measurement by the liquid meter system by more than the prescribed allowance of error. |
| (i) | Where a liquid meter system is provided with a temperature-compensating device, such device must be tested for efficiency and shall not affect the accuracy of measurement of the liquid meter system by more than the prescribed allowance of error. |
| (j) | Where an automatic temperature-compensating device is provided with a setting device for selecting various densities or coefficients of expansion of liquid to be measured, such setting device must be tested for efficiency and must not affect the accuracy of measurement by the liquid meter system by more than the prescribed allowance of error. |
| (k) | Any test may be repeated as many times as the market surveillance inspector or verification officer considers necessary. |
| (l) | Where practicable the through-put during a test must be not less than the quantity delivered by the liquid meter in the course of one minute. |
| (m) | Where the flow rate or capacity or other circumstance precludes the testing of a liquid meter system by direct comparison with a certified measure of volume, the net mass of liquid delivered through the liquid meter must be determined by means of a weighing instrument complying with the relevant requirements in SANS 1698 and, for the purpose of comparing its volume with the liquid meter reading, such net mass must be converted to measure of volume on the basis of the average temperature at which the liquid has passed through the liquid meter system and the density of the liquid at such average temperature, and where a liquid meter system is provided with a temperature compensating device the mass so determined must, for the purpose of comparing its volume with the liquid meter reading, be converted to a measure of volume at 20°C on the basis of the density of the liquid at 20°C: Provided that any liquid meter system tested in terms of this subregulation must be provided with a means for measuring the temperature of the liquid stream at the liquid meter. |
| (n) | The National Regulator may compile and supply test sheets and tables of density and conversion factors for use by a market surveillance inspector or verification officer in carrying out the various prescribed tests applicable to liquid meters or liquid meter systems. |
| (o) | The National Regulator may prescribe test procedures for the testing of automatic temperature compensating devices. |
| (7) | Except as otherwise provided in this regulation or in any regulation relating to a liquid meter of a specific class or kind or used for a specific purpose, error is permissible on a liquid meter in accordance with Table 20, Table 21 and Table 22. |
1 |
2 |
3 |
TABLE 20 |
||
For a new or repaired liquid meter system |
||
Capacity of tank or compartment |
Error allowed |
|
At flow rates from half-maximum up to maximum |
At flow rates below half-maximum |
|
In excess only |
In excess only |
|
Up to 500 mL |
5 mL |
5 mL |
Over 500 mL and up to 2 L |
1% |
1% |
Over 2 L and up to 4 L |
20 mL |
20 mL |
Over 4 L and up to 50 L |
0,5% |
0,5% |
Over 50 L and up to 100 L |
250 mL |
0,5% |
Over 100 L |
0,25% |
0,5% |
1 |
2 |
3 |
4 |
5 |
TABLE 21 |
||||
For a liquid meter system in actual use when verified by a market surveillance inspector or verification officer. |
||||
Quantity tested |
Error allowed |
|||
At flow rates from half-maximum up to maximum |
At flow rates below half-maximum |
|||
In excess only |
In deficiency |
In excess |
In deficiency |
|
Up to 500 mL |
5 mL |
2,5 mL |
5 mL |
2,5 mL |
Over 500 mL and up to 2 L |
1% |
0,5% |
1% |
0,5% |
Over 2 L and up to 4 L |
20 mL |
10 mL |
20 mL |
10 mL |
Over 4 L and up to 50 L |
0,5% |
0,25% |
0,5% |
0,25% |
Over 50 L and up to 100 L |
250 mL |
125 mL |
0,5% |
0,25% |
Over 100 L |
0,25% |
0,125% |
0,5% |
0,25% |
1 |
2 |
3 |
TABLE 22 |
||
Drain test: For a new, repaired or liquid meter system in actual use when verified by a market surveillance inspector or verification officer. |
||
Product tested |
Error allowed |
|
At flow rates from 0 to 500 L/min |
At flow rates from 500 L/min up to maximum flow rate |
|
Petrol |
- 1 L |
- 1,5 L |
Diesel, Paraffin |
- 1,5 L |
- 2 L |
| (8) |
| (a) | The verification mark must be applied in a position as described in the type approval documentation, if not described it shall be applied in a conspicuous, essential and accessible part of the liquid meter housing. |
| (b) | Protective marks (seals) must be applied to the measuring instrument to prevent unauthorised access to any adjusting device or working parts, or in a position as described in the type approval documentation. |