Working for Dunea certainly brings rewards for Mr. van Zwieten and his colleagues, as the views across the dunes are simply magnificent. Indeed, as Mr. van Zwieten starts his tour outside the main office building it is impossible not to stop and stare for a moment or two and to admire the scenery. But these dunes are not just an eye-catching backdrop for they constitute a key step in the company’s purification systems. As Mr. van Zwieten explains, water is pumped from the River Maas onto the dunes where it is allowed to sink slowly through the layers of sand.
“This natural filtration process is very effective at killing off bacteria. To the best of my knowledge there are only a handful of other companies who are doing this. They are also based in the Netherlands so this technique is something we are all very proud of,” states Mr. van Zwieten.
The water sinks slowly through the sand for a minimum of 30 days (with an average of 90 days), after which it is pumped up for further purification. Opening the secured doors to one of two pumping stations Mr. van Zwieten points to some of the valves and actuators that have been installed. As might be expected, butterfly valves are very much in evidence as is an electric actuator on the outlet pipe.
“This actuator for example is an older model but still working fine. In this environment actuators can easily function for twenty years or more. Of course modern actuators do offer benefits, so older models would normally be replaced as and when a pumping system is refurbished. Or we might consider replacement earlier if advised that spare parts were no longeravailable.”
Whilst talking about valve procurement Mr. van Zwieten notes that Dunea has standardised its actuator configurations. This makes the process of specification and One of the points he checked was the breakaway torque, which gives us the reassurance that the valve will indeed work properly on demand.”
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