Round valves with housing made of aluminium, steel and stainless steel. Flange type and size depend on customer requirements. We develop valves with sizes up to 3000 mm and in different temperature ranges. Check valves work by means of a pressure differential. If the inlet pressure rises above the minimum opening pressure threshold, the valve opens and the flow is let through. If the inlet pressure falls below the minimum opening pressure again, the valve closes automatically. Similarly, if the back pressure is too high, causing the pressure differential to fall below the minimum opening pressure, the valve closes. Backflow valves are mainly used in applications where backflow causes problems. This valve is a cheap and effective solution to this problem.