Ultrasonic flow measurements without compromising drinking water hygiene
Supplying drinking water over long distances requires complex pipe networks and high pumping capacity.
Replacement of damaged invasive measuring probes at highly demanding measuring points in the long-distance water supply system
The transport of drinking water from remote hydroelectric power stations to the municipal utilities’ transfer points, the overcoming of differences in terrain elevation involved in this process, right through to the provision of drinking water and its supply to end customers in a region, requires an extensive pipeline network and extremely high amounts of energy in the form of pumping capacity. Often, several pumping stations are involved in carrying out this task, which can result in high water pressures within the pipeline network. Whilst these high pressures – which usually occur before the water enters distribution stations – are necessary for transporting the water, they can also lead to certain problems at the end of a long-distance water supply route.
A flow measurement point operated by an East German long-distance water supplier, which was extremely challenging due to these high pressures, required a new measurement system solution, as a vortex flow meter previously installed at this location could no longer withstand the water pressure loads during full-load operation and had been damaged. The faulty measuring probe was to be replaced by a non-contact measuring principle: a permanently installed ultrasonic clamp-on solution. It was essential to avoid any contact between the measuring system and the high-pressure medium. An even more important reason ultimately left the customer with little choice but to consider only a non-intrusive flow measurement method: maintaining the hygienic conditions of the drinking water.
The customer had already had positive experiences with two portable, non-invasive KATflow 200 flowmeters. Following an inspection of the very confined measurement point, the decision was therefore made to install a stationary ultrasonic flow meter of the KATflow 150 type, featuring a wide range of output options for integration into the customer’s network via an analogue output and a Profibus interface. The measurement system to be installed was required to deliver measurement results quickly and reliably, as the pipework ran through a critical area beneath a motorway and there were concerns that a leak could cause damage to the building structure.
Commissioning of the measurement system was also part of the overall package and was carried out by Katronic. Thanks to the very simple installation of the sensors – using a clamp-on technique – supplied with the ultrasonic flow meter, no process interruption, modification or opening of the pipework was necessary. From then on, there was no longer any need for regular flushing to remove deposits from invasive measurement sensors. The purchase costs of the new measurement system were significantly lower than those of comparable invasive measurement technology, whilst the personnel and logistical costs for commissioning were many times lower.
The installed measurement system delivered reliable data to the control room without interruption, ensuring continuous monitoring of the affected section of the network and rapid intervention in the event of a fault. The measurement accuracy of the ultrasonic flow meter was expressly praised by the customer and verified by comparative measurements, as a result of which Katronic will also be consulted for future measurement tasks.
