Flowmeters for high volume gases and large flow rates

The key to precise metering and control of gases is ensuring that the equipment installed to perform the task is accurate, reliable and capable of integrating with other system controls. The main issue with measuring the flow of gas is that the accuracy can be reduced by changes in temperature and pressure.

Bürkert Fluid Control Systems has perfected the art of gas handling, with a range of monitoring and control products, which has now been extended by the introduction of two new gas flowmeters, specifically for high volume gases and large flow rates.

Flowmeters for large flow rates

The Type 8007 and Type 8008 flowmeters use the calorimetric principle of flow measurement, meaning the accuracy of the flowmeters can be assured since they are unaffected by changes in temperature and pressure.

What is the calorimetric principle of flow measurement?

A heated sensor element is cooled down by the gas flow. This cooling effect, which depends on the flow velocity and the gas characteristics serves as a flow indication. The kind of cooling directly depends on the flow velocity and the kind of gas. This kind of mass flow measurement is independent of pressure and temperature. The flow measurement principle can be used for monitoring air supplies, but also qualifies for the measurement of other gases.

This method of flow measurement requires no moving parts, therefore not only does this increase the overall reliability of flow measurement, but it also provides relatively high accuracy at low flow rates. Furthermore, both flowmeters provide a 4-20mA analogue output signal which can be used to control a huge range of components such as process control valves and solenoid valves either directly or via a PLC.

To ensure the accuracy levels specified, it is essential that flowmeters are installed correctly and that they are located in an undisturbed gas stream. This is determined by the design of the pipework both upstream and downstream of the sensor location.

Type 8008 gas flowmeter

The Type 8008 is designed for pipe sizes up to 2" and can used to monitor air supplies as well as for measuring other gases. The flowmeter has an integral display which can be configured to display the measured flow in a variety of units as well as maintaining a value for the total volume measured. As standard, the maximum flow is 825 Nm3/h, with special flow ranges available on request, while the maximum operating pressure is 16 bar.

Type 8008 gas flowmeter

Type 8007 gas flowmeter

The Type 8007 flowmeter can be used in pipe diameters ranging from 1/2" up to 12" (DN300) and it features a depth scale that ensures that the sensor is correctly positioned within the pipe. Available in 3 versions: Basic, Extended and Maximum, each calibrated for a velocity range, 85.2 m/s, 170.1 m/s and 206 m/s respectively. The capacity of this product type ranges from 41 Nm3/h for 1/2" pipe up to 44,030 Nm3/h for a Maximum version installed in a 12" pipe, with a maximum operating pressure of 50 bar.

Type 8007 gas flowmeter