Q: Water Pipe Flow Measurement

Extended Reading: LORA water meter Water flow measurement in water pipes generally refers to measuring the water velocity or water flow in the pipe. Sometimes, people will choose to cut off the pipe. Then install a pipeline flow meter to measure the water flow. Sometimes, people can also clamp the flow sensor on the outer wall of the pipe. Directly measure the water flow without destroying the original pipeline. Further reading: Inline water flow meters

Question 1

Water Pipe Flow Measurement

Accepted Answer

Extended Reading: LORA water meter

Water flow measurement in water pipes generally refers to measuring the water velocity or water flow in the pipe.
Sometimes, people will choose to cut off the pipe. Then install a pipeline flow meter to measure the water flow.
Sometimes, people can also clamp the flow sensor on the outer wall of the pipe. Directly measure the water flow without destroying the original pipeline.

Further reading: Inline water flow meters

Question 2

Open Channel Flow Measurement

Accepted Answer

Open channel flow meters can be used in harsh environments. Such as urban water supply diversion channels, sewage treatment inflow and discharge channels, and corporate wastewater discharge.
Next, we will introduce to you the specific method of open channel flowmeter such as flow measurement.

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Measurement methods of open channel flowmeters: water level method, velocity area method.

Water level method: measurement is achieved by measuring the upstream (or upstream and downstream) water levels of the water measuring buildings and converting them into flow through empirical formulas or experimental curves. The water level method flowmeter needs to build a water measuring structure, and the accuracy is not high.

Velocity area method: A commonly used flow measurement method in open channels. The flow is obtained by measuring the cross-sectional area of the water passing through and the velocity of the cross-section. The velocity area method does not require the construction of water measuring buildings. High precision. And it is not affected by the supporting water downstream. Optional electromagnetic flowmeter or Doppler flow rate tester.

Extended reading: Make Ultrasonic Open Channel Flow Meter Work for You

Question 3

The Electromagnetic flowmeter measures water flow

Accepted Answer

The electromagnetic flowmeter can measure the speed of the water by using a simple magnetic field.

When water passes through a magnetic field, a voltage is generated. In this way, higher flow rates always generate more voltage when sent through the electromagnetic flowmeter. The electronic system connected to this meter will receive the voltage signal and convert it into volume flow.

Remember that the water needs ions to generate voltage, which means that the electromagnetic flowmeter cannot be used with pure water without pollutants.

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Extended Reading: 3 inch (3″) Water Meter

Question 4

Turbine/mechanical flow meter to measure water flow

Accepted Answer

Turbine flow meters easily become the most common flow meters around, mainly because these flow meters are more affordable than other types.

The mechanical flow meter measures the water flow through the rotation of the turbine, which uses a basic propeller, blade, or split flow design. The flow rate of water is equal to the speed of the blades.

If mechanical flow meters are to be used, they may become clogged if the water is dirty or more contaminated than expected.

Therefore, you probably should not use this kind of flowmeter to measure the flow of slurry. Since these flow meters can become clogged, they are more frequently maintained than other flow meters.

Know more about: Turbine type Flow Meter for Liquid & Gas technology

Question 5

Vortex flowmeter measures water flow

Accepted Answer

The vortex flowmeter is a unique flowmeter that measures the flow of water by using vortex flow.

When the fluid pushes over the obstacle, it will produce a vortex and form a vortex. The flowmeter is equipped with a sensor tab. As long as the vortex flows through the sensor tab, the tab will bend, which will produce a frequency output indicating the flow rate of the water.

If you decide to choose a multivariable vortex flowmeter, it can measure up to five different variables that are useful for your specific application.

These variables include mass flow, temperature, density, flow rate and pressure. These meters are especially suitable for large pipelines.

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Question 6

Ultrasonic flow meter to measure water flow

Accepted Answer

Ultrasonic flow meters are designed to use ultrasonic technology to measure the speed of water as it passes through the pipeline.

You should understand two basic types of ultrasonic flow meters, including runtime flow meters and clamp-on ultrasonic flow meters.

If you choose a run-time flow meter, send a standard ultrasonic signal downstream before sending another signal upstream. These two signals are then compared to determine the water flow rate. This is mostly a pipeline water flow meter. It is often used for household water.

For clamp-on ultrasonic flowmeters, can be placed outside the pipe and are designed to emit acoustic pulses through the pipe wall in order to receive the measured value. Since they can be installed outside the pipeline, they can be used for almost any application and can be used with larger pipelines.

Extended reading: Industrial VS Residential inline water flow meters

Question 7

Rotameter for Water

Accepted Answer

Rotameter is also called float flowmeter. Rotameter is composed of three units: float flow sensor part, displacement-angle conversion mechanism part, and information conversion processing part. It is a traditional variable area flow measurement device. When the flow rate changes, the float moves up and down in the vertical tapered tube. The circular flow area formed between the cone and the float changes. It is a volumetric flow meter that realizes flow measurement based on this principle.

Extended reading: Metal Tube Flow Meter-Variable Area Flow Meters Principle

Rotameter can measure water and gas. But you must explain the medium and flow range with the manufacturer when selecting the model. The method of calibration by the manufacturer is different. The completed flowmeter cannot be used mutually.

Extended reading: Liquid Bitumen/Asphalt Flow Meter

Question 8

Flowmeter method

Accepted Answer

Use a flow meter to directly measure the flow of the river. There are many types of flow meters, mainly including differential pressure, electromagnetic, launder, and weir flow meters. It can be selected and used according to the actual flow rate range and test accuracy requirements.

Extended Reading: Chilled Water Flow Meter

Question 9

Volume method

Accepted Answer

Put the river water into a container of known capacity. Measure the time it takes to fill the container. Repeat the measurement several times. Find the average value t(s). A method to calculate the amount of water.

This method is simple and easy to implement, and the measurement accuracy is high. It is suitable for rivers with small river flows. However, there should be a proper drop between the overflow outlet and the receiving water body or an error can be formed by the aqueduct.

Question 10

Buoy method

Accepted Answer

Select a straight river section. Measure the area of the cross-section of the water flow within a 2m interval of the river section. Find the area of the average cross-section.
Put a buoy in the upper reaches of the river and measure the time it takes for the buoy to flow through a certain section (L). Repeat the measurement several times. Get the average of the required time (t), and then calculate the flow velocity (L/t). The flow can be calculated as follows:

In the formula, Q is the water flow, the unit is m^3/min. v is the average flow velocity of the water flow, and its value is generally 0.7L/t, and m/s.S is the average cross-sectional area of the water flow, the unit is m^2.

Question 11

Flow rate method

Accepted Answer

Calculate the river flow by measuring the cross-sectional area of the water flow, measuring the river water velocity with a flow meter.
During the measurement, the number of vertical and horizontal measurement points at the point must be determined according to the depth and width of the channel. The method is simple, but it is easily affected by water quality and difficult to achieve continuous measurement.

Understanding the relationship between Flow Rate and Pressure may help you calculate mass or volume flow.

Question 12

What is the unit of flow measurement?

Accepted Answer

Flow is the volume of fluid that passes in a unit of time. In water resources, flow is often measured in units of cubic feet per second (cfs), cubic meters per second (cms), gallons per minute (gpm), or other various units.

Users can also choose unit of flow rate. For volume flow, L/s, L/min, L/h, m3/s, m3/min and m3/h are available; while for mass flow, kg/s、kg/m、kg/h、t/s、t/m、t/h can be selected from. It is up to the habits and application requirements to pick up a proper unit.

Extended reading: Liquid Bitumen/Asphalt Flow Meter

Question 13

How is flow rate calculated?

Accepted Answer

There are many ways to calculate flow.
For example, Using the Flow Rate Formula: Q = A × v.
where Q is the flow rate, A is the cross-sectional area at a point in the path of the flow and v is the velocity of the liquid at that point.

Or, Flow Rate Calculation Using Pressure:

Extended reading: Orifice Plate Flow Meter

Question 14

What is the water flow meter?

Accepted Answer

A water flow meter is an instrument that can measure the amount of water passing through a pipe. There are a variety of water flow meter technologies to choose from. It depends on the water measurement application, budget terms, and maintenance requirements. Each of these flowmeter types has novel process principles, overall use value and unique advantages in use.

The water flow meter can measure hot water, cold water, clean water, dirty water and mud.

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