You have in the apartment or private home installed water meters of 15 mm diameter (DN 15) and a cross and a half cubic meter per hour. This means that for the hour counter via a dialed 7 water baths. In the calculation of the standard I took a bath volume of 200 liters.
Hydrometer larger diameter of 20 mm (DN 20) and a flow rate of 12 full baths (2,5 m3) per hour, meaning set at honest No citizen. Such a high consumption is not needed in an apartment or house. But there are two good reasons for the ban on the counters of larger diameter.
The reasons for the ban.
1)Counter 20 mm has a larger measurement error than the counter smaller diameter (15 mm). So that the passage of the water at low costs, taking into account the instrument can be considered in the smaller side than it actually is. Which is beneficial to the consumer.
2)Water meter 20 mm. do not respond to a small water flow.
We, in the private sector, even when allowed to put counters at twenty, summer filled vat tanks with water in a thin stream. Thus the meter does not respond to the water passing therethrough. Also, excluding the counters 15 mm., Manage some seniors fill water bath for further flushing the toilet. Especially this trick is done easily on meters that stood for 2-3 years. They formed growths that impede the rotation of the impeller unit.
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