What component can help avoid pressure build-up in a hydraulic system?

A pressure relief valve plays a critical role in a hydraulic system by allowing excess fluid to bypass and return to the reservoir when the system pressure exceeds a predetermined level. This function is essential for maintaining safe operating conditions, as it prevents pressure build-up that could potentially damage components or lead to system failure. By providing an escape route for excess pressure, the pressure relief valve ensures that the hydraulic system operates within its designed limits, enhancing both safety and reliability.

The other components listed serve important functions within a hydraulic system but do not specifically address the immediate need to control pressure. For example, hydraulic fluid coolers are designed to maintain the temperature of the fluid, ensuring optimal performance, while variable displacement pumps adjust the flow rate based on system demands. Piston accumulators store hydraulic energy but do not directly relieve pressure. Thus, while each component has its purpose, the pressure relief valve is uniquely suited to prevent pressure build-up.