A proportional pressure control valve uses an electromagnetic coil to generate controlled magnetic force. A current‑controlled valve driver typically uses PWM to regulate coil current, producing smooth, repeatable actuation. As commanded current changes, the coil force moves an internal control element such as a pilot stage or spool against hydraulic forces and a spring, shifting the valve to a new pressure setting.
In proportional relief valves, the valve protects a pressure line by opening to tank when system pressure reaches the electronically commanded setting, limiting maximum pressure. Adjusting coil current shifts the opening point, enabling continuous pressure changes during operation.
In proportional reducing and relieving valves, the valve regulates inlet pressure to a control port to maintain commanded downstream pressure. If control‑port pressure rises above the setting due to external forces, the valve relieves excess pressure to a relieving port to hold the desired level.