Fast Unloading Valve

Date:2016/7/12 20:35:12 Visits: Author:Dongfang YOYIK Engineering Co; Ltd,

China Steam Turbine Fast Unloading Valve Manufacturer

 

 

PRODUCT DESCRIPTION

 

The fast unloading valve is installed on the oil actuator of steam turbine. When the emergency shutdown is needed, the needle valve of the unloading valve can be pulled out immediately to shutdown the unit.

 

When the steam turbine unit malfunctions and requires emergency shutdown, the quick unloading valve quickly releases pressure oil during emergency tripping devices and other actions, causing the valve to close and play a protective role.

 

Operation process:

When the unit malfunctions and the protection action or manual shutdown occurs, the emergency trip oil discharge loses pressure, causing the cup shaped slide valve in the unloading valve to move up under the action of the lower high-pressure oil, opening the oil port connecting the high-pressure oil and the return oil of the oil cylinder. The pressure oil in the lower chamber of the hydraulic motor piston is quickly released, and under the action of the valve spring, the valve is closed to achieve the protection purpose. 

 

 

Working principle of fast unloading valve

· Normal operation:

The emergency trip solenoid valve is closed → the pressure oil in the cylinder is connected to the trip oil through the throttle hole and enters the oil chamber in the upper part of the slide valve → the trip oil is established → P1=P2 → the force of the oil pressure in the upper part of the slide valve plus the force of the spring is greater than the force of the pressure oil in the lower part of the slide valve → the slide valve is closed by pressing on the base → channels 1 and 2 are separated → the high-pressure oil is connected to the lower chamber of the cylinder → the valve opening is not affected

 

·  Interruption signal appears:

Crisis trip solenoid valve opens → Crisis trip oil loses pressure → Trip oil P1 drops → P2 pressure oil overcomes the force of the spring to open the cup shaped slide valve → 1 and 2 oil passage are open → The lower chamber of the oil cylinder is connected to the return oil → The valve quickly closes

Note: The AST solenoid valve is closed when energized, and the OPC solenoid valve is closed when de-energized; When OPC solenoid valve is opened, only high pressure regulating valve and medium pressure regulating valve are controlled; when AST solenoid valve is opened, emergency trip oil is discharged and all valves are controlled.

 

 

REGULAR SPARES

 

Unloading Valve HF02-02-01Y	Unloading Valve PCV-02-B10
Unloading Valve DPV-00	HP Unloading Valve M-3SE10U20/315W220NZ5L
Unloading Valve CVC-40-N	Unloading Valve DB20-2-30/31.5XV

 

PRODUCT PICTURE

 

 

 

RELATED PRODUCTS

 

Regeneration circulating pump	EH Oil System Main Pumps	Servo valve	AST solenoid valve

 

 

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