BS EN ISO 4064-5:2014 pdf free
BS EN ISO 4064-5:2014 pdf free.Water meters for cold potable water and hot water
To ensure accurate measurement and prevent galvanic corrosion at the electrodes, the meter and the measured fluid shall be electrically connected at the same potential. While in general this means earthing the water, the individual installation instructions for a particular meter design shall be followed.
On a conducting but uninsulated fluid pipe, without a non-conducting internal coating, the connecting point(s) of the primary element of the meter shall be electrically linked to the secondary element and both connected to earth.
On non-conducting pipes, or pipes isolated from the fluid, metal earthing rings shall be interposed between the pipe and the primary element of the meter. These shall be electrically linked to the secondary element and both to earth.
Where the fluid cannot be earthed for technical reasons, the meter may be connected without referencing the fluid potential, but only when the meter model and manufacturer’s instructions permit.
For other requirements for electromagnetic meters, ISO 6817 shall apply.
Meters operating in parallel or in a group
Means shall be provided to permit installation, reading, servicing, in situ dismantling and removal of any meter, without interference from, or interfering with, the operation of any other meter in the group.
For multiple meter operation, with common outlet, check valves shall be installed, downstream of each meter, to prevent back flow through the meter.
For multiple meter operation, means shall be provided, affixed on or immediately adjacent to each water meter, to identify the source or delivery each water meter is registering.
Water meters should have protective devices installed which can be sealed in such a way that after sealing has taken place and the water meter has been correctly installed, there is no possibility of removing the water meter or its adjustment device without visibly damaging the protective devices.BS EN ISO 4064-5 pdf download.
