The Jacques Avias pumping station at the karst spring of the French river Lez south-east of Les Matelles supplies the entire Montpelliers community with fresh drinking water. Since 1982, tandem submersible motor pumps from the German pump manufacturer Pleuger have been pumping 1700 litres of drinking water per second from three well shafts to the surface. A fourth pump discharges 250 litres of water per second into the Lez, which is one of Europe's "Natura 2000" protected areas and is home to unique animal species such as the Petit Groppe. After 30 years of operation, the Montpellier Water Board commissioned Pleuger to replace two pumps that had reached the end of their maintenance cycle.
The pumping station at Les Sources du Lez was equipped by Pleuger at the begin-ning of the 1980s with two-stage submersible motor pumps - specially dimensioned for the application and designed for trouble-free operation for 30 years. It is the only source from which the people of the metropolitan region receive their water. Only a routine maintenance after 15 years planned by the water protection authority "La Régie des Eaux" was to interrupt the operation of the machines at short notice. After 30 years, two of the 20-ton and 10-metre-long twin units were replaced in accord-ance with the regulations. Pleuger was again awarded the contract for the project because, on the one hand, the uniformity of the original functional group was to be maintained and, on the other hand, the Pleuger brand was to ensure maxi-mum reliability due to years of cooperation.
The new 32-inch centrifugal pumps are two-stage special designs: The water-cooled stainless steel motor is located below the hydraulics and supplies spring water from the underground cavern via a suction-pressure jacket. The drinking water flows through a single-stage grey cast iron pump hydraulic system into the connected pressure boosting system of the same type, which transports the drinking water 34 metres upwards.
Since the investment in the Pleuger pumps pays for itself after 15 years, but are designed to last twice as long, a cost-covering and trouble-free water supply for the entire Montpellier metropolitan region is guaranteed.
Pump unit type: QN362-1a + VNI22-150-6
Head: 36 m
Flow rate: 3500 m³/h
Power output: 590 kW
Rated current: 1020 A
Operation via frequency controller