Which component is used to limit system pressure to a safe maximum?

• A. Relief valve
• B. Accumulator
• C. Selector Valve
• D. Filter

Answer: (A)

Pressure control in hydraulic and pneumatic systems is achieved with a device that acts as a safety valve. The relief valve is a spring-loaded device that stays closed while system pressure is below its preset limit. When pressure climbs to that limit, the valve opens and diverts fluid back to the reservoir or to another part of the circuit, preventing the pressure from rising further. This keeps the entire system within safe operating limits and protects pumps, hoses, seals, and actuators from overpressure.

Other components serve different roles. An accumulator stores energy and helps smooth pressure changes but does not actively cap the system pressure. A selector valve changes where fluid flows, not how much pressure the system is allowed to develop. A filter removes contaminants, with no direct role in limiting pressure.