Why does a 5 port solenoid valve not work correctly with low pressure (0.1 MPa)?

The spool of a 5 port solenoid valve is operated using air pressure from the inlet port of the valve.

If the pressure supplied to the inlet port of the valve is less than the minimum working pressure (generally around 0.1 to 0.2 MPa, depending on the particular product), there may not be sufficient pressure available to ensure the correct operation of the spool.

If you require a 5 port solenoid valve for use with low pressure, we recommend that external pilot or direct operated type valves are selected.

Internally piloted type valves generally use a small direct operated 3 port pilot valve to supply the pressure to the main valve. When the solenoid of the pilot valve is operated, pressure is directed to the spool of the main valve causing it to operate.