The difference between pilot solenoid valve and direct acting solenoid valve

Direct-acting solenoid valve, after the coil is energized, the electromagnetic coil generates electromagnetic force to lift the seal from the valve seat, and the valve opens; when the power is off, the electromagnetic force disappears, the spring presses the seal on the valve seat, and the valve closes.

Features: It can work normally under vacuum, negative pressure and zero pressure, but the general flow path is relatively small, within 10mm, suitable for working conditions with low working pressure and unable to establish sufficient working pressure difference. The 2W-160-15 model produced by NINGBO SMART PNEUMATIC Company belongs to the direct-acting solenoid valve.

Step-by-step direct-acting type, also known as zero-pressure differential solenoid valve, is a combination of direct-acting and pilot-operated. When there is no pressure difference between the inlet and the outlet, the pressure difference between the inlet end and the outlet end is allowed to be zero. After energization, the electromagnetic force directly lifts the pilot small valve and the main valve closing member upward, and the valve opens. When the inlet and outlet reach the starting pressure difference, after the energization, the electromagnetic force leads the small valve, the pressure of the lower chamber of the main valve rises, and the pressure of the upper chamber drops, so that the main valve is pushed upward by the pressure difference; when the power is off, the pilot valve uses the spring The force or medium pressure pushes the closure and moves down to close the valve.

Features: It can also operate at zero pressure difference or vacuum, higher pressure, but because the pilot part has a large opening distance, the working pressure is not as high as the pilot solenoid valve.

Pilot-operated solenoid valve: When energized, the electromagnetic force opens the pilot hole, the pressure in the upper chamber drops rapidly, and a pressure difference between the lower part and the lower part is formed around the closing member. The fluid pressure pushes the closing member upward and the valve opens; when the power is off, the spring The force closes the pilot hole, and the inlet pressure passes through the bypass hole to form a lower low-high pressure difference around the valve member, and the fluid pressure pushes the closing member downward to close the valve. Pilot-operated solenoid valves are suitable for working conditions with high working pressure, stable performance and long diaphragm life.