The steam turbine emergency trip system is a device specifically designed to quickly cut off the fuel or steam supply to the turbine in case of emergency, in order to protect the turbine, surrounding equipment, and personnel safety. When a steam turbine encounters critical situations such as overspeed, high temperature, low oil pressure, etc., it can play an important role.

An important part of the emergency trip system is the emergency trip valve. By controlling the valve to close, the shutdown circuit is automatically activated, and the inlet valves (including main steam valves and regulating valves) are quickly closed. Once the emergency trip solenoid valve is triggered, the operator must immediately inspect and repair it to determine the root cause of the problem and take appropriate measures to solve the problem.

The detection of critical faults in steam turbines can be carried out in two ways: mechanical and electrical. Depending on the type of trip, there are also different forms of trip valves. Yoyik mainly introduces the two most commonly used types: trip directional valves and mechanical shutdown electromagnets.

Mechanical Trip Isolation Valve F3DG5S2-062A-220AC-50DFZK-VB-08

The mechanical trip isolation valve F3DG5S2-062A-220AC-50DFZK-VB-08 is a solenoid directional valve mainly used in mechanical hydraulic emergency trip systems. This system is a mechanical overspeed fault detector. When the speed of the steam turbine is over 3300r/min, a ring flies out under the action of centrifugal force, causing the emergency trip device to trip. The emergency trip device drives the trip valve in the trip isolation valve group to reverse and remove the high-pressure safety oil. After the high-pressure safety oil is released, the one-way valve will also release the overspeed limit safety oil, causing the control oil pressure on the unloading valves of each inlet valve hydraulic servomotor of the steam turbine to disappear and each unloading valve to open. Therefore, the upper and lower pressure oil of each steam valve hydraulic actuator piston is connected to the oil discharge port through its opened unloading valve, thereby quickly closing each inlet valve. After the main steam valve is fully closed, a limit switch signal will be given, and each check valve will be closed through the electrical and control circuit.

Magnetic Trip Device 3YV

Unlike the previous type of mechanical trip valve, the magnetic trip device 3YV is used for electrical emergency trip systems. It uses electrical methods to detect various faults of the steam turbine, as well as faults such as generator tripping and boiler main fuel tripping, and then simultaneously applies the electrical trip signal to the mechanical trip solenoid (3YV). Energize the 3YV electromagnetic iron and activate the shutdown mechanism to trip the emergency trip device. Although the signal after the main steam valve is fully closed can cause the extraction check valve to close, various electrical trip signals will directly act on each check valve while acting on the aforementioned solenoid valves, causing them to quickly close.

Although these two types of valves have different working principles, their significance for the safe operation of steam turbines is equally important. Yoyik provides the emergency trip valves F3DG5S2-062A-220AC-50DFZK-VB-08 and 3YV in strict accordance with the technical requirements of the steam turbine unit, which is a reliable choice for power plant users.