Non-return Valves

989AT and 990 series non-return valves are designed to allow aircraft system fluid (e.g. fuel, air or hydraulic fluid) to flow in one direction while preventing its backflow. They are used in aircraft fuel, hydraulic and pneumatic systems for protection of system units and maintaining desired operation modes.

989АТ-1-12, 989АТ-1-14, 989АТ-1-16, 989АТ-1-20, 989АТ-1-25, 989АТ-2-25, 989АТ-2-32, 989АТ-2-40, 989АТ-2-50, 989АТ-2-60, 989АТ-2-70, 989АТ-2-80, 989АТ-2-90, 989АТ-2-100, 989АТ-3-32, 989АТ-3-50, 989АТ-3-70, 989АТ-3-100, 990-4-4, 990-4-6, 990-4-8, 990-2-14, 990-5-8, 990-5-14.

The operating principle is based on automatic movement of the closure element when exposed to fluid pressure. A forward flow causes the valve to open, while in case of pressure drop or backflow the closure element is pressed against the valve seat closing the passage tightly.