The need for accurate flow measurement isn’t restricted to specific pipe sizes.  In fact, because of the huge quantities of liquid flowing through large diameter pipes, the need for accurate measurement is just as important – if not more so.

The production and transportation of fresh water by the Saline Water Conversion Corporation (SWCC) in the Kingdom of Saudi is a case in point. Unlike many other countries where water is often considered to be of very low value, in the KSA the production of water has a real and significant cost, making accurate measurement important. This importance is multiplied when dealing with pipe diameters of 1m and above, capable of flowing hundreds if not thousands of cubic metres per hour.

For new systems, designers typically rely on established techniques such as full-bore electromagnetic or ultrasonic flow meters. However, when looking to retrospectively install accurate metering into an existing pipe line some very real challenges are faced which require a new way of thinking.

SAFIA worked closely with SWCC to understand the challenges they faced implementing accurate metering into existing, large diameter pipe lines. In many instances shutting down the pipe line requires extensive planning and cannot happen quickly. In other instances, the operation is so critical that it cannot be shut-down at all or only for very limited periods of time. This either prevents the installation of full-bore flow meters or dramatically delays their installation. The challenge faced by SWCC and given to SAFIA was to provide a measurement solution which was capable of installation without disrupting the network and was available immediately.

SAFIA’s experience with clamp-on ultrasonic metering suggested this was a potential solution, but there is a world of difference between the claims made by a manufacturer and the performance of a meter in the real world. SAFIA quickly recognized that a practical demonstration of the clamp-on meter’s accuracy was vital and so a series of evaluations were undertaken at different locations. These compared the performance of the clamp-on ultrasonic meter with a recently installed full-bore electromagnetic flow meter. More importantly, the electromagnetic meter had been calibrated at an accredited facility prior to installation and the installation met or exceeded the manufacturer’s requirements.
The evaluations delivered excellent results with differences always less than 1% and often very much lower. This demonstrated the suitability of the solution proposed by SAFIA and gave SWCC the confidence to proceed with the installation of this metering technology.