Most flow meters are made of the primary device, a transducer and a transmitter. These three flow meters parts are usually combined so that the flow meter is one complete instrument. Flow meters vary in terms of measuring technique and design and are therefore used across many fields and industries. Certain flow meters are manufactured using specific materials in order to maximize results. The cleanliness of the air, fluid or gas is an important factor as is the viscosity. The process pressure, process temperature and size of the pipe should also be taken into account. Manufacturers understand how important flow meters are to everyday industrial processes. Flow meters are used for efficiency purposes and to help companies determine profit gain or loss. Industries that benefit from the value of flow meters include the automotive, petroleum, gas, utility services, HVAC, food and beverage processing, chemical and raw material industries.
Some of the most popular flow meters are: peak flow meters, water flow meters, fuel flow meters, air flow meters, ultrasonic flow meters and flow monitor services. Many flow meters measure the volume of the material while other flow meters measure the speed, and still other flow meters measure the mass of the materials. For the most part, flowmeters are used to infer mass flow through calculations that flow meters and flow monitor instruments make after taking various flow measurements, such as absolute pressure, differential pressure, viscosity and temperature. Flow switches, however, typically have a fourth component that serves as a switching unit to control flow. They may also trigger a visual or audible alarm. Flow indicators, which are observation windows in industrial processing lines, aid in measuring flow by visual indicators. Vortex flow meters measure the flow rate by placing an obstruction directly in the flow path, forcing liquids or gases to move around it. When the flow moves around this obstruction, or bluff body, two symmetrical vortices are created on the opposite side, changing the pressure of the flow. A sensor is placed between these vortices to measure these changes in pressure, transmitting this data to an electronic signal conditioner outside the meter.
Flow meter distributors manufacture various instruments for different measurements of flow. Thermal mass flow meters take measurements with two sensors that work together. A temperature sensor reference and an active heated sensor take measurements by calculating how much heat loss occurs in the flowing liquid, and thus these flow meters can determine the flow rate based on this amount. Another type of flow meter is the Coriolis flow meter, which operates on the basis of the Coriolis Effect. In the Coriolis Effect, an excitation force is applied to the flow meter tube, causing the fluid or gas to rotate because the acceleration is acting in opposite directions on both sides of the applied force. A flow meter measurement can then be taken. Other kinds of flow meters operate using sound: these are called ultrasonic flow meters. Another type of flow meter is an electromagnetic flowmeter, which is a type of volumetric flow meter that functions based on Faraday's law of electromagnetic induction. Also, there are rotometers, which utilize a rotating float that moves vertically through a tapered tube. Most of these designs and types are mounted in one of the three basic mounting styles: in-line, insertion and non-invasive.
Flow meter manufacturers offer various instruments for different measurements of flow and there are four main categories of air flow meters that are identified based on how they obtain a reading of the flow rate or quantity of air. Differential pressure air flow meters are the most common type. These devices take both a primary and a secondary measurement and report the difference. The first measurement causes a change in kinetic energy by directing the air through a hole in the flow meter which is measured by the second element. Positive displacement meters separate the air flow into specific volumes which are then counted. Vanes, gears, pistons, or diaphragms are commonly used to divide the air which is counted mechanically or electronically. Velocity air flow meters use a depth measurement and the average air velocity of the flow to produce a reading. They have a greater range than differential pressure devices. The last category is true mass air flow meters. They directly measure the mass of the fluid, not the volume. Each type of flow meter has specific guidelines that must be followed for proper use. For example, when using gas flow meters, the flow meters must remain full of gas. Liquid in gas flow meters can affect the flow meter's accuracy. Similarly, in order for liquid flow meters to work properly, they must remain full of liquid. Gas in liquid flow meters can affect the accuracy of flow meters' readings, as well as contaminants of any kind.
Flow Meters Companies - Sierra Instruments
Flow Meters Companies - Sierra Instruments
Flow Meters Suppliers - GPImeters.com
Flow Meters Suppliers - Hydra-Check
Flow Meters Companies - John C. Ernst Co., Inc.
Flow Meters Suppliers - John C. Ernst Co., Inc.
A flow meter is an instrument used to measure the flow of a liquid or gas in a supply pipe. The device is fitted into a pipe to gauge the quantity of gas or liquid passing through it. These appliances are available in a wide variety to diverse industrial applications. For different applications, there are different names given to flow meters - such as, gas flow meter, liquid flow meter, flow indicator, flow gauge, etc. The purpose of these devices is the same, while their capacity and several features may vary according to the application requirement.
The significance of accurate measurement is inevitable for many industries. They need to be sure of the accuracy of their machines and processes, in order to keep up with their production demands and meet consumer or user expectations. Therefore, it becomes very important for flow meter manufacturers to ensure the accuracy of their appliances.
Some variations, for example, positive flow meters, are offered by some manufacturers. These devices help the engineers at your plant to directly measure real-time and accurate volume of gas or liquid flow in a piped system. These appliances render a precise output signal for the volume of gas or liquid crossing the mechanism. This output signal is directly connected to the force that the passing gas or fluid applies on the sensor of the device. Apart from mass or force, the output signal is correlated to the velocity of the flow. Other factors that affect or have a direct connection with the signal accuracy are turbine or rotator wheel, plate, channel, nozzle, laminar, and pilot table.
How to determine whether the flow meter that you are buying is the best for your application
Since flow meters are available in lots of options, it may be confusing for decision-makers to decide which type will be suitable for their process. There are different types of flow meters for different purposes and capacities. The theory of "one size fits all" does not apply here. Deliberating that you can use just any type for your process would be an impractical decision. You need to make sure that the design and capacity that you are investing in is the one for your process equipment. You should invest in a technology that is new, tested, and suggested for your systems.
If you are looking for a flow meter, then the following descriptions will help you choose an appropriate flow gauge for your process -
Gas or liquid
One of the most important points to have in your consideration is the medium, in which you will mount the device. A point to be noted here is -gas and liquid friendly flow meters have different features, such as water resistance.
You also need to have the flow rate of gas or liquid in mind.
How accurate do you want the output signal to be?
Your accuracy demand should be the second most important consideration. This particular factor varies across industries.
Last but not the least, the temperature that your process application attains during the run should be in your checkpoints.
Various types of flow meters are available on the market. It is important that you know the function, merits, and application of each type. We will present all the information you need about each type.
To measure the flow, this type of flow gauge uses annular orifice that is formed by a tapered cone and piston. Scales on piston flow meters are based on specific gravities of fluid; for oil meters, it is 0.84 and for water meters, it is 1.0. Their unique selling point is the simplicity of design. They have become economical alternative to rotameters, since they can be installed easily to transmit electrical signals.
This type of flow indicator consists of a tapered tube and a float. They are most commonly used for measuring gases and liquids. Advantages include linear output, simplicity, low cost, low-pressure drop, and wide range ability.
Also known as Coriolis flow meters, they work based on pressure, density, and fluid viscosity, using either a temperature sensor and differential pressure transducer or a heated sensing element. They have built-in digital displays, as well as analog outputs. They are popularly used for leak testing and low flow measurements.
Turbine flow meters are very accurate; they have an accuracy of 0.5% of the reading. They have application in clean and viscous liquids. The meter has a multi-bladed rotor that is mounted at right angles to the flow. The outputs are a sine wave or square wave frequency, and if you need signal conditioners, it can also be mounted, however, only on explosion proof classifications.
They are used in measurement when straight pipe is not available. They are a replacement for turbine meters and paddlewheel sensor, when too much turbulence is in the flow. The positive displacement has application in viscous liquids.
Flow meters are a measuring device that comes built in appliances used across industries. The device helps the engineers to measure the speed, force, and pressure applied by air or liquid flow. Flow meters are divided in two categories: gas-based and fluid or liquid-based flow meters.
If we focus on fluid-based flow meters, then we can classify them in five subcategories, such as Differential Pressure Flow Meters, Velocity Flow Meters, Positive Displacement Flow Meters, Mass Flow Meters, and Open Channel Flow Meters.
Differential Pressure Flow Meters
Differential pressure flow meters were devised on the Bernoulli Equation, that itself was based on the flow of fluids. These meters can be put into various sub-types, such as Orifice Plates, Flow Nozzles, Venturi Tubes, and Rotameters.
Orifice Plate - Using these systems, you can measure the change in the pressure of the flow, going from upstream to downstream. However, for such measurement, it is important to have the flow in a partly blocked pipe.
Venturi Tubes - These flow gauges help in measuring the liquid flow rate. The device checks the change in pressure, which occurs due to a cross sectional flow area in the flow path.
Flow Nozzles - Flow nozzles can be used for measuring both air and gas flow rates. They are simple in design and cost is minor.
Rotameter - Rotameters have a straight-up plastic tube that is larger at the upper end. The device measures the pressure applied on the fluid by the Earth's gravity.
Velocity Flow Meters
Velocity flow meters calculate the flow of the fluid by sensing the speed at more than one point in the piping system. With such devices, it becomes possible for process engineers to maintain the required flow throughout the stream. Some of the types of velocity flow meters are:
Pitot Tubes - These are the most popular, most used and cheapest fluid flow meters. These devices are installed in most ventilation and HVAC systems of today. This flow meter checks the velocity of the flow by translating the kinetic energy into the potential energy.
Calorimetric Flow Meter - These meters have two temperature sensors that are fixed closely as a touching base for the liquid. Due to their intelligent design, these flow meters can provide highly accurate air flow readings.
Turbine Flow Meter - The flow is used to move or rotate the turbine and the device measures the speed of the turbine. That is the simple working principle of this flow meter.
Some other velocity-based flow meters are Vortex Flow Meter, Electromagnetic Flow Meter, and Ultrasonic Flow Meter.
Positive Displacement Flow Meter
PD flow meters measure the flow using their rotors as sensor or flow measuring element. The volumes of the airflow are displaced in these devices. The rotation of the rotors is directly related to the volume of the flow being blown toward it.
Mass flow meters are used for the direct measurement of mass flow, while open channel flow meters allow the engineers to determine the flow by checking the height of the liquid.
Performance and accuracy of flow meters are determined by selecting the right meter. An improper selection accounts for major problems that users face with meters.
Selection of a compatible meter for pressurized systems is confusing, as various types of flow meters are available, such as peak flow meters, Coriolis flow meters, ultrasonic flow meters, electromagnetic meters, and vortex meters.
To get a suitable flow meter, it must complement the system it will be installed in. Here, we will provide information about flow control related products that will help you to buy the right match for your system. To select a proper flow meter, you need to have an understanding of the requirements for a particular application. Time invested in evaluating fluid processes and overall installation can save you money through operation, repair, and maintenance.
You need to know the characteristic of the fluid, such as specific gravity, Newtonian or non-Newtonian, conductivity, and vapor pressure at operating temperature. You also need information about the fluid's composition, toxicity, presence of particles in fluid, size of particles, and light transmission qualities-- whether it is opaque or translucent.
Second thing that you need to know about is the range of flow of the medium, either gas or fluid, in your system. The range of flow will help you to eliminate some options that do not work properly in the range. Some meters work better with low flow rate, while some with higher rate. You can check the capability of a meter in terms of range of flow in the specifications that comes with a product.
A meter should be able to measure both the instantaneous quantity (Qi), the rate at which water is pumped, and the total quantity of water flowed over time (Qa). The Qa is usually recorded in gallons. However, some meters can measure Qa in acre-feet. These types of meters are used in agriculture applications.
It is important to determine the required flow measurement accuracy, since the performance of a flow gauge may not be acceptable over the full range of flow. You can get it determined in terms of percentage of calibrated span, actual reading, or full-scale units. Absolute accuracy is critical in certain applications, where a product is sold based on meter reading. In some other applications, repeatability can be a more important factor than absolute accuracy. Determining you need will help you to have a meter that will work optimally.
You need to know the area where the flow indicators will be located. Meters are not installed in the area where vibrations are inherent or where magnetic field can interfere with the meter. The direction of flow is also considered; in liquid applications, it is advised to avoid downward flow. Some meters need straight pipe to work properly; however, the required length of pipe can be compensated using straightening vanes.
To ensure that only a right flow meter is installed for a particular system, get the checklists, questionnaires, and specification sheets from the manufacturer. These sheets are specifically designed to give the critical information necessary to match the flow meter with the requirement.
Flow meters are used to measure the flow of air, fluids and gas. A flow meter is an instrument used to measure linear, nonlinear, mass or volumetric flow rate of a liquid or a gas. Many flow meters measure the volume of the material while other flow meters measure the speed; other flow meters measure the mass of the materials.
Flow meters are essential for applications that require precision analysis of the movement of fluids or gases. Some flow meters are designed to measure for a specific material while other flow meters can detect a variety of materials. These devices will commonly utilize two different measuring styles: mass flow or volumetric flow. Devices that calculate for mass flow determine the characteristic of a material in terms of pounds or kilograms while systems that measure for volumetric flow will produce results in liters or cubic inches. Companies that have applications such as brewing, medical treatments or fuel distribution would benefit from accurate flow meters.
There are several factors that contribute to proper flow meter operation. For example, if the substance being measured has foreign contaminants then the flow meter will not register the proper readings. Flow meters can improve the efficiency of a facility by assisting in monitoring fluid consumption or other applications. There are several types of flow meter designs including peak flow meters, water flow meters, fuel flow meters, air flow meters and ultrasonic flow meters. These instruments can determine the absolute pressure, differential pressure, viscosity and temperature of the substance being monitored. There are three typical mounting styles: in-line, insertion, and non-invasive. Flow meters can also be designed for safety. Flow meters can transmit data to outside panels to indict pressure or temperature changes. Vortex flow meters are installed in the flow path of the fluids or gases and this style meter measures the flow rate by forcing the substances to move around the sensor. If the readings become alarming then the operator can act accordingly to avoid a bigger problem.
Absolute Pressure - Atmospheric pressure plus gage pressure in flow
Accumulator - Area where fluid is under pressure and stored as a source of power within flow meters.
Bluff body - An obstruction, often wedge-shaped, placed in the middle of a gaseous or liquid flow designed to create a downstream vortex in vortex flow meters as a means of measuring flow rate.
Control Point - The temperature flowmeter instruments need to maintain to
perform designated functions of flow meters.
Coriolis Force - The force that occurs when a mass has a velocity moving outward in a rotating plane of flow meters.
Counter Weight - A mass that is added to a particular substance to create a more balanced and stable apparatus for flow meters.
Current - The flow rate of electricity within flow meters.
Density - A substance's mass per unit of volume in flow meters.
Flow - The travel of materials in response to a force, such as pressure within flow meters.
Flow Nozzle - A constriction made of a contoured plate that forms a hole in flow meters for the flow stream so a flowmeter measurement can be taken.
Flow Rate - The velocity of flow in flow meters.
Head-Loss - The loss of pressure in flow meters or a flowmeter system that is measured with a length parameter (such as amount).
Hot-Tap - Allows for flow meters to be inserted or removed without causing a complete system shutdown.
Integrator/Totalizer - A flow meters device that measures the total flow of fluids.
Manometer - Measures fluid pressure. This is a U-shaped flowmeter tube containing liquid which adjusts with the pressure in the flowmeter tube.
Mass Flow Rate - The volumetric flow rate of a liquid or gas times its density, expressed as pounds per hour or kilograms per minute in flow meters.
Potential Energy - The potential of energy when a liquid is in a position or height above a flowmeter place to which it can potentially flow.
Transducer - The part of flow meters that sense fluid as it passes through the flowmeter device.
Transmitter - The part of flow meters that produce the usable flowmeter information from the transducer of flow meters.
Weldolet - A connection for a metal pipe that is used to aid as a fitting for insertion-type sensors or flow meters.