How does the spool valve work?
A spool valve features seals along its surface. By actuating the valve, the spool shifts, causing the seals to travel down the bore and opening the ports to allow for airflow. For systems that have a flow of 100 gpm or less, spool valves are most commonly used to direct flow.
What is the spool on a hydraulic valve?
A spool valve is part of a hydraulic system that directs the flow of hydraulic fluid. The valve is made up of spools that rotate or slide to block and open channels in a hydraulic system.
How do hydraulic spools work?
Hydraulic systems use fluid to increase the mechanical ability of the system. The spool inside the cylinder directs the movement of the hydraulic fluid to create pressure where needed. Applying power to the spool valve’s solenoid changes the direction of the hydraulic fluid, thus moving the fluid pressure.
How do you test a hydraulic spool valve?
To check this, install a pressure gauge and flow meter in the drain/tank port line. All hydraulics work on differential pressure. If back pressure is excessive, the actuation pressure must overcome it first before it can move the spool. Most systems require minimum back/drain pressure to function smoothly.
What color is hydraulic fluid aviation?
purple
What are the three types of hydraulic fluids?
Three common varieties of hydraulic fluids found on the market today are petroleum-based, water-based and synthetics.
- Petroleum-based or mineral-based fluids are the most widely used fluids today.
- Water-based fluids are used for fire-resistance due to their high-water content.
What are the types of hydraulic fluid used in aviation?
There are three types of hydraulic fluid commonly used in Aviation:
- Mineral oil-based Fluid. ➔ MIL-H-5606 – Oldest one. ➔ MIL-H-6083 – Rust-inhibited version of MIL-H-5606.
- Synthetic hydrocarbon-based Fluid. ➔ MIL-H-83282 – Polyalphaolefin-based fluid.
- Phosphate ester-based Fluid. ➔ Skydrol – Types IV and V.