Measuring flow rate in any liquid industry that processes or uses liquids gases is critical if you want to achieve high productivity and profitability. For these to happen, plants and companies should use proper flow meters or measurement instruments meant for that particular application. Flow meters measure the flow rate of different fluids and gases, which is essential for any industrial process. But how important is accuracy in flow measurement? That is what we are going to discuss in this article. If you want to learn more about the benefits of accuracy when measuring flow rate, continue reading this post.
To maintain high safety standards and quality in fluid or liquid production, accurate flow measurement is necessary. That is why standards are set in flow measurement and any other type of measurements to determine accuracy. In portable water applications, accurate pump control is critical. Accurate flow measurement aims to enhance efficiency while tracking the volume of distributed water or any other fluid in the system. This calls for effective flow measurement devices and techniques.
High-Pressure Flow Measurement Devices for Oil Industry
Benefits of Accuracy in Flow Measurement
Background
Accuracy is critical when regulating fluids flowing through pipes to reduce lead in piped products. In the United States, the U.S. Environmental Protection Agency’s Safe Drinking Water Act (SDWA) must be complied with when dealing with components of potable water systems. Standards used here are established by NSF International, which is a non-governmental and non-profit organization well versed with health matters and expertise on environmental science.
Portable water applications are addressed with Drinking Water System Components—Health Effects and NSF/ANSI Standard 372: NSF/ANSI Standard 61: Drinking Water System Components—Lead Content. While Standard 32 deals with measurement methods for determining “lead-free” substances, drinking water approval is governed by NSF Standard 61. Safety standards of products that come into contact with potable water are governed by both Standards 372 and 61. These standards demand that certification should be acquired as an entire system for prefabricated domestic pump systems.
Pump Performance
Inflow regulation, accuracy are important in applications that deal with food and beverage. In such processes or any other industrial process that require high hygiene standards, pumps should comply with SDWA. This flow measurement standard demands that pumps should be easy to clean and disassemble. When designing such pumps, nonhazardous materials such as stainless steel should be used. Accuracy is also important in such applications since they are occasionally characterized by reduced water consumption and low flow. Advanced tech has made it easier to create hydraulic systems with large pipes which provide low overall volume capture and low-flow velocities.
Pumps generate volumetric flow. Therefore, fluid properties largely determine flow precision. Some of the process conditions that may cause inaccuracies to include wear and tear of components, temperature change, air entrapment, and pressure variation.
The reason why the accuracy of pump flow rate is important and should be metered is that:
- It helps to Make it easier to get distribution system losses by subtracting the total of readings from the total supply
- This helps to optimize disinfection
- That allows operators to treat corrosion
- Overall pipe performance is monitored
- In custody transfer, it helps to determine gross billings
The fluid flow is used to determine the pump’s performance, which affects accuracy in flow measurement. Performance curves and specifications knowledge helps to understand pump performance.
Selecting Ideal and Accurate Flow Metering Technology
There are many types of flow meters designed to offer accuracy based on the application used in the flow measurement industry. This applies mostly to pumps that are used in water distribution. Flow meters can either work mechanically or electrically when monitoring, sensing or measuring flow rate. Liquid turbine and electromagnetic meters are the most commonly used flow meters in the water flow measuring industry. Liquid turbine flow meters with stainless steel wetted components are better used to measure water flow rate. Ultrasonic flow meters – both clamp-on and inline are also among the most used flow meters.
Turbine Flow Meters
For smaller line sizes flow meters, turbine flow meters are the right technology. These meter types are also inexpensive compared to other flow meters. Therefore, they are ideal metering options for users who want to achieve repeatable, accurate, and wide turndown flow measurements.
A high-resolution pulse rate output signal is produced by turbine flow meters proportional to fluid velocity and volumetric flow rate. Turbine flow meters are best used with clean fluids and require regular maintenance and calibration due to moving parts found inside. Lead-free bronze alloys are also used to make particular turbine flow meter types. This allows them to be certified to the NSF/ANSI standards since they comply with lead-free drinking water provisions. Flow meters that are designed with lead-free alloy contain certified components.
We have the nutating disc flow meters for smaller lines, which are used mostly to meter water flow. These meter types provide high accuracy and repeatability. However, performance in nutating disc flow meters is affected when viscosity below the threshold.
Electromagnetic Flow Meters
Electromagnetic flow meters are efficient when metering portable fluids since most of them are conductive. In addition, such flow meters provide high accuracy, which is essential when operating low-cost pumps.
Many applications prefer using electromagnetic flowmeters because they offer affordable flow rate measurements for conductive fluids in the long run. With these flow meter types, the operator can achieve up to ± 0.2% accuracy, and pressure loss is virtually eliminated with its open-flow tube and non-intrusive design. Since these types of flow meters have no moving parts, they are hardly affected by fluid conditions such as pressure, viscosity, and temperature change. However, they have to be correctly specified. Electromagnetic flow meters provide linear flow signals. Their outputs are encoded, and they hardly lose accuracy even when turnover reaches 20-to-1 or better.
Ultrasonic Flow Meters
Noncontact ultrasonic flow meters are proffered in many industries because they comply with NSF regulations. In addition, they are easily installed since pipes don’t need to be cut it disturbed. Modern ultrasonic flowmeters give a turndown ratio that is similar to electromagnetic flowmeters. In addition, sampling rates and power have been increased in these meter types.
To establish bidirectional flow rates, special types of ultrasonic flow meters called transit-time ultrasonic flow meters are used. When measuring flow rate using these meter types, waves are transmitted upstream and downstream in the flowing fluid and through the pipe wall. The flow velocity is given once the flow meter calculates the difference in the travel time based on the pipe size.
Clamp-on transit-time ultrasonic meters don’t require maintenance since they don’t have any moving or wetted parts. They also don’t suffer pressure loss. Any flow changes in terms of temperature or other properties are reported by measuring the speed of sound of the fluid or liquid. If there are any issues with the flow, clamp-on ultrasonic flow meters can troubleshoot them, especially in pumps, which increases accuracy.
Conclusion
From this post about the importance of flow accuracy and flow measurement, it is plain to see that accuracy is critical in any industrial process dealing with fluids. If you want to increase the accuracy of the measured flow rate, you need to match the right flowmeter with the right application. If you are not sure, most manufacturers will guide appropriate applications.
