Air Check Valve
Air flow check valves help to prevent damage to your aquarium air pump. It is a simple home aquarium safety precaution that is useful whenever an air pump is housed below the aquarium water level.
This device will prevent water back flow through the air hose when the electricity source to your air pump is disrupted. This can occur as a result of the siphon which may form within the hose.
Many make do without these devices and ensure there is no water back flow by keeping the air pump above the water level. If this is impractical then an air check valve will be the only option.
The internal valve is made of rubber and this component will become less pliable in time. For this reason the air check valve should be replaced periodically to maintain the usefulness of the product.