A summary of the common knowledge of water meters that you need to know

The water meter is the fair device for measuring the payment of water resources. The water meter is also a necessary equipment for thousands of households, and it is also the basis for energy saving and economic expenditure. However, the perception of water meters by outsiders is only a kind of instrument, and the understanding of water meters is also very small. Let us learn about the common sense of water meters.

 

The Chinese water meter trading network said that the meaning of each symbol in the water meter naming indicates that the first L of the water meter represents the flow meter, the second represents the water meter, the third type of water meter, the S represents the third horizontal position of the rotor type horizontal screw-wing water meter. Horizontal screw-wing vertical screw-wing water meter third position R stands for vertical screw-wing double water meter (combined) water meter third place F stands for double-type quantitative water meter third position D stands for quantitative hot water meter fourth position R stands for hot water The fourth position of the water meter L stands for the fourth position of the vertical positive and negative flow meter. The N represents the positive counter current. The fourth position G represents the fourth position of the dry liquid seal water meter. The Y represents the liquid seal. The detachable water meter is the fourth place. C stands for the detachable type. Why do you see bubbles on the surface of the water meter?

 

Answer: The water meter is divided into wet type and dry type according to the counter form. The tap water can enter the counter is wet type, the counter seal is dry type, the air released from the accumulated water on the surface of the wet water meter forms bubbles, and the bubbles on the surface do not affect the water meter. Measurement.

 

Q: Can the water meter be installed diagonally?

Answer: The water meter should be installed according to the installation method (H-horizontal or V-vertical) and the direction of water flow. The mechanical water meter has rotating measuring elements inside. The center of gravity of all rotating elements rotates the most smoothly on the rotating shaft, so The accuracy of the metering when the water meter is installed obliquely cannot be guaranteed.

 

Q: What are the requirements for upstream and downstream pipelines?

A: The upstream section of the water meter is required to install a straight pipe section with a diameter of 10D and the same length of the water meter. The downstream of the water meter requires a diameter pipe (D) and a straight pipe section of the same length of 5D. In order to avoid excessive stress on the water meter, it should be ensured that the axis of the upstream and downstream pipelines and the pipe fittings coincide.

 

Q: Is there any requirement for the life of the water meter? 

Answer: For the nominal caliber less than or equal to 50mm, and the commonly used flow rate does not exceed 16m/h, the water meter used for trade settlement is only used for the first mandatory verification, and is used within the time limit and expires. The water meter under rotation will fulfill the scrapping procedures.

The service life of water meters with a nominal diameter of 25mm or less is generally not more than 6 years; the service life of water meters with a nominal diameter of more than 25mm to 50mm is generally not more than 4 years;

 

Q: What influences the accuracy of the water meter?

A: There are currently three kinds of situations: one is that the surface is rusty, or the foreign matter is blocked by the mud; the second is the aging of the parts, which is deformed or damaged by the water pressure; the third is that the numbers are unclear, resulting in misreading and misreading. ”

 

Introduction of various flow of water meters. Starting flow QS: the flow rate that causes the water table minimum gear pointer to start rotating; Minimum flow rate Qmin: The minimum value of the water meter's rated flow range. Depending on the accuracy level of the water meter, such as Class A water meter: 3% of the nominal flow rate Qn; Class B water meter: 2% of the nominal flow Qn.

 

Introduction of various flow of water meters. Starting flow QS: the flow rate that causes the water table minimum gear pointer to start rotating; Minimum flow rate Qmin: The minimum value of the water meter's rated flow range. Depending on the accuracy level of the water meter, such as Class A water meter: 3% of the nominal flow rate Qn; Class B water meter: 2% of the nominal flow Qn....

 

Nominal flow Qn: Maximum flow at rated operating conditions. Provision: The nominal flow of DN15 is 1.5 m3/h; the nominal flow of DN20 is 2.5 m3/h; the nominal flow of DN25 is 3.5 m3/h. Some "N2.5" on the water meter means "the nominal flow rate of the water meter Qn is 2.5 m3/h", so that the diameter of the water meter is DN20. (Personal traffic is used by people who are also used to call common traffic). Overload flow Qmax: The maximum flow that the water meter can withstand within the accuracy level, generally Qmax = 2Qn. 2) National Standard of the People's Republic of China GB/T 778.1-3—2007 and metrological verification procedures.