114.Quick closing valve

Fuel is drawn the service tank through a quick closing valve. These can be closed remotely in case of emergency (e.g. fire). This can be done with simple pull wires, hydraulically, or in this case by compressed air.

Quick closing valve is a kind of pressure reducing valve in which the an automatic process control valve for fluid pressure control is used for unmanned machinery spaces. This can be done by careful selection of valve trim, i.e. the parts of the valve that come in contact with the controlled fluid and form an actual control portion. The difference between pressure release valve and quick closing valve is that the later does not come in direct contact with the fluid it is controlling.

The lever is connected externally to a remote operating mechanism which might be pneumatic or hydraulic controlled. The controlling system has a piston which moves with the pressure of air or fluid and simultaneously moves the lever attached to it. The lever at the other end is connected externally to the spindle which is attached internally to the valve.The valve is a spring loaded valve which means that the spindle is placed through a spring which helps in re-positioning of the valve to the open position when the air or fluid pressure in controlling cylinder reduces.

All the quick closing valves are generally set in the open position.When the piston of the controlling cylinder moves up, the end of the lever which is connected to the piston moves up. As the lever is pivoted at the center, the other end of the lever moves down and pushes the spindle downwards. This closes the valve and shuts the flow of the fluid.