There are four AST solenoid valves in steam turbine HP oil station, which are controlled by the turbine shutdown signal. During normal operation, the solenoid valve 300AA00126A is energized and closed, blocking the AST oil drain channel on the emergency trip main pipe, thereby establishing the emergency trip oil pressure. When the solenoid valve loses power and opens, the emergency trip main pipe leaks oil, and the emergency trip oil loses pressure, causing all steam valves to close and causing the turbine to stop. The four AST solenoid valves are arranged in series and parallel. Only when at least one solenoid valve is activated in groups 1, 3, 2, and 4, will the AST oil pressure be released and the machine stop.

AST solenoid valve 300AA00126A online test method

Two sets of pressure switches and a local display pressure gauge are installed on the pipeline to monitor pressure and meet the online testing function of the 300AA00126A AST solenoid valve. During normal operation of the system, the ASP oil pressure is about 7.0Mpa. During online testing, the ASP oil pressure must be normal and only the AST solenoid valve can be powered off individually, and cannot be conducted simultaneously.

During normal operation, the oil pressure to the pressure switch is the system pressure, and the pressure switch contacts are closed. When the system pressure drops to a certain value, the pressure switch contact opens and sends a signal to the outside.

The steam turbine uses many types of solenoid valves for regulating valve speed control. Yoyik can offer various types such as below model numbers:
22FDA-F5T-W110R-20/LP
23D-63B
22FDA-F5T-W220R-20/LBO
300AA00086A
300AA00126A
0508.919T0301.AW027
AM-501-1-0148
AM-501-1-0149
Z2804076
Z2805013
Z6206052
Z6206060
ZD.02.009
ZD.02.004
GS020600V
2YV
SV13-12V-0-0-00
SV4-10V-C-0-00
PD10-40-0-N-170
SV13-12V-O-0-00
PCV-03/0560
ZS1DF02N1D16