The check valves of Lasso Technologie AG are equipped with a diaphragm to prevent the back flow of liquids and gases. When the membrane is closed, only a low noise level is generated and water hammer is avoided. The anti-reflux valve guarantees a reliable closure even with granular liquids (sandy water). In addition, our diaphragm check valves serve as raw filters and thus secure pumps and systems. We guarantee a long product life thanks to the absence of moving mechanical parts subject to wear.