A spool valve is a type of valve that uses a spool to control fluid flow. The spool is a cylindrical metal with a hole in the middle. The spool is connected to a lever that can be moved to open or close the valve. When the valve is open, fluid can flow through the hole in the spool and out of the valve. When the valve is completed, the liquid is blocked from flowing through the hole in the spool.
Spool valves are used in a variety of applications, including hydraulic systems, pneumatic systems, and fuel injection systems. They are often used when precise control over fluid flow is required.
The function spool valve fails when the spool gets stuck in the closed position. This can happen for some reasons, including dirt or debris getting lodged in the spool or damaged or worn out. When the spool is stuck closed, it prevents the flow of hydraulic fluid, which can cause the system to fail.