The emergency trip control block mainly consists of the following components: pressure switch, orifice, AST solenoid valve, pressure gauge and pressure transmitter. Together, these components form a two-way, two-valve sequence or cross-connection system to ensure reliable system action.

AST solenoid valve CCP230M is a key component in the emergency trip control block. Emergency Trip Unit (ETU) is a key safety device in thermal power generation units such as steam turbines. It can quickly disconnect the unit from the power grid when an abnormality occurs during unit operation to protect equipment and personnel safety.

In the emergency trip control block, there are 4 AST solenoid valves CCP230M arranged in dual channels. A pair of odd-numbered AST solenoid valves is 1-channel, and a pair of even-numbered AST solenoid valves is 2-channel. The solenoid valves adopt series-parallel hybrid connection. After the unit is connected to the gate, all four solenoid valves are energized.

When the unit is locked, that is, after the AST oil pressure is established, P2 (the pressure in the high-pressure chamber of the actuator) is approximately half of P1 (the pressure in the safety oil chamber of the actuator), which meets the conditions for opening the main steam valve and the regulating valve. When the two channels operate at the same time, remove the AST oil pressure, close the main steam valve and the adjustment valve of the unit, and realize the unit protection trip. When only one of the channels is active, such as any solenoid valve malfunctioning, P1 remains unchanged and the unit does not trip. At the same time, when any solenoid valve refuses to operate, the unit protection can still operate normally. This design ensures that the protection system will fail only under double faults, greatly improving the reliability of the system.

There are also two orifices in the AST module. Firstly, it is to form a series-parallel structure to make the system more reliable. Secondly, it is to reduce the required flow rate of the system and reduce power consumption. Due to the use of a dual-way dual-valve sequence or cross-connection system, not only the reliable operation of the system is ensured, but also when any valve does not operate or is tested online, the system still has a protective function.

The oil from the oil pump enters the actuator through the high-pressure main pipe, flows all the way to the solenoid valve or servo valve, and is controlled by the solenoid valve or servo valve to enter the high-pressure chamber of the actuator. The high-pressure chamber of the actuator is the same as the pressure chamber of our unloading valve. connected, and the other path passes through a throttle hole and enters the safety oil chamber of the unloading valve of the actuator. At this time, the safety oil flows out of the other small hole in the safety oil chamber of the unloading valve and enters the AST through the check valve on the actuator. mother pipe, so that the safety oil pressure of the actuator is completely controlled by the AST module. As long as the AST module takes corresponding actions, the related actuator will be shut down.

Yoyik can offer many spare parts for power plants as below:
solenoid valve J-220VAC-DN10-AOF/26D/2N
globe valve 80FWJ1.6P
oil pump ACF090N5ITBP
Plugs-with valve 20SBAW10EVX
DC LUB OIL PUMP 125LY23-4
Spigot Ring P29617D-00 for dome valve DN200 P29617D-00
valve PP3-N03BG
OPC solenoid valve SV13-12V-O-0-00
Butterfly Valve BDB-250/150
Cooling fan YB2-132M-4
solenoid valve J-220VAC-DN10-D/20B/2A
Inflatable seal dome valve-DN200 P5524C-01
Drain Valve M-3SEW6U37/420MG24N9K4/V
Servo valve G631-3017B
EH oil shock-absorbing pipe clamp SP320PA-DP-AS