Non-return valves

Non-return valves, also known as shut-off valves, stop valves or check valves, allow the flow of fluids or gases in only one direction. They prevent reversal of the direction of flow, or the potential return flow of fluid or gaseous media such as compressed air, water, oil or steam in the opposite direction. Non-return valves open automatically, as soon as fluids are flowing. If the flow stops or if the direction of flow changes, the valves likewise close automatically. In this way, non-return valves prevent backstreaming in pumps, and also prevent pipes and tanks from running dry.

The most common types of non-return valves are ball check valves or spring-loaded safety valves. A spring-loaded valve has a closing element in the form of a plate, and a spring. In case of a pressure drop the closing element is closed by means of the spring. Meanwhile, the fluid medium flows in the other direction of the closing element. If the flow stops, stopping the pressure of the plate on the spring, the latter springs back into its starting position. This causes the line to close again and the fluids can no longer flow. A ball check valve works the same way as a spring non-return valve. Instead of a plate, however, there is a ball, which presses on the narrowing part of the closing element during flow in the desired direction, therefore closing the passage.

Non-return valves are used in diverse systems and industries, to ensure maximum functional reliability and to prevent damage to machines and devices. AIGO-TEC valves are used for example in fuel and coolant circuits, and also in pneumatic (tool) systems and emissions aftertreatment systems. 

Depending on the requirements of the customer, AIGO-TEC non-return valves use sealing systems such as a ball, a flat seal, or an O-ring. We develop and produce custom-tailored non-return valves according to your requirements. The valves are made of various materials, such as brass, steel, stainless steel and aluminium. The seal materials are chosen on the basis of the particular application and your individual requirements. We will also be glad to implement low opening pressures and a broad selection of different connections to the medium-carrying system.

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