These valves feature four ports enabling complete directional control – pressure connects to one port while the opposite port drains to the tank. When energized, internal spool movement reverses these connections, extending or retracting the cylinder as needed for precise positioning.

Pilot-operated valves use system pressure to assist spool movement, reducing electrical power consumption while handling larger flow capacities. Direct-acting models respond faster and work in zero-pressure conditions but consume more electricity. Your application’s pressure and flow requirements determine the optimal choice.

Aluminum provides significant weight reduction, essential in mobile applications like construction and agricultural equipment. Brass offers superior machinability and traditional reliability for stationary industrial systems. Both materials handle standard hydraulic pressures, though brass typically costs less for smaller valve sizes.

DC voltages (24V, 30V) are suitable for mobile equipment with battery-powered systems, providing faster response times. AC options (110V, 220V) work well in stationary industrial installations with consistent power supplies. 4-way valves with lower DC voltages reduce electrical interference in sensitive electronic control systems. 

Two-position valves switch between extended and retracted positions only – ideal for simple on/off cylinder control. Three-position designs add a neutral center position for holding loads or allowing free cylinder movement. Most applications requiring precise positioning benefit from 3-position functionality.