Pneumatic Control Valves for Marine Pneumatic Devices

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shahchiragg
24th May 2021
Marine Automation System Ship Automation System

Pneumatic control valves are integral components of marine ships. Generally, pneumatic devices use a nozzle and flapper system to produce a variation in the compressed air signal. A pneumatic control valve is made up of two parts and they are the actuator and the valve.

How do pneumatic control valves operate?

A flexible diaphragm forms a pressure-tight chamber in the upper half of the actuator and then, you need to feed the controller. The movement of the diaphragm results in a movement of the valve spindle and the valve. The diaphragm movement is hindered by a spring and is usually arranged in such a way that the variation of controller output corresponds to the full travel of the valve.

The valve body is arranged to fit into the particular pipeline and houses the valve and seat assembly. Valve operation may act directly. The enhancing pressure on the diaphragm closes the valve.

As pressure on the diaphragm enhances, the reverse acting valve opens. The diaphragm movement is stalled by a spring that will close or open the valve in case of air supply (depending on the action of the valve).

The valve disc or plug may be single or double seated and can come up with various shapes. Based on the relationship between valve lift and liquid flow and the type of control required, various shapes and types are selected. A non-adjustable gland arrangement is usual. Inverted V-ring packing is used to lessen the friction against the moving spindle. A valve positioner is used to achieve accurate valve disc positioning and combat the effects of friction and unbalanced forces.

The controller signal acts on a bellows to move the flapper concerning the nozzle. This movement will modify the air pressure on the diaphragm. This pressure is supplied through an orifice from a relentless pressure supply. The diaphragm movement will move the valve spindle as well as the flapper. If the valve disc is correctly positioned, an equilibrium position will be set up. This arrangement allows the use of a separate power source to activate the valve.

Ship Automation is a reputed company which deals with various ship spare parts like ship automation system, marine automation system, pneumatic control valves, and marine control system. The company has a wide range of pneumatic control valves including Rexroth 3410400000, Aventics 0821302440. To know more, just visit the website of ship automation.

Burkert 2002 | 3-way valve