A manufacturer of modular washing and sorting plants for building and excavation materials installs pinch valves from the VM series from AKO Armaturen in the factory. These valves are used to control the taking of water samples.
The modular washing and sorting plants clean soil, clay, asphalt, stones, concrete and many other substances and classify the output according to size. The operator of the plant thus receives clean bulk goods that have been sorted into specific substances such as gravel or sand. Foreign substances such as metal can also be filtered out of the process and sent for recycling.
The pinch valve is not directly used in the washing process but rather in the taking of samples:
A sample of the water used to clean the material is pumped into a sample vessel. After the water has had time to settle, any particles contained within it will fall to the bottom of the vessel and trigger sensors. This signifies that the washing process has not yet been concluded. The process is then repeated until the water is free of dirt particles.
After each of the tests, the pinch valve installed at the base of the vessel opens and allows the water to return to the circuit.
Due to the high control pressure of 5.0 bar at an operating pressure of just 1.0 bar, the sleeves already needed to be replaced after three years. As a differential pressure of 2.0 to 2.5 bar is sufficient for the AKO pinch valves, AKO Armaturen contacted the operator and recommended reducing the differential pressure to 2.0 bar at a control pressure of 3.0 bar. This change is expected to double the service life of the installed sleeves.
The operator is very pleased with the current situation and the installed pinch valves from the VM series and describes their design and operation as “brilliant”.
Sludge, contaminated soil, water
Opening and closing cycles:
Approx. 1,000 / day
(reduced to 3 bar after recommendation from AKO -> doubling the service life of the sleeves)
Nominal size: DN 20
Series: VM (replacement series VMP)
Connections: Internal thread, POM
Sleeve: Natural rubber (abrasion-resistant)
Global market leader
Unique delivery promise
Widest pinch valve product range
Extensive service activities