When does a relief valve discharge fuel oil according to pressure limitations?

A relief valve is designed to maintain safe pressure levels within a system by discharging excess pressure to prevent potential hazards. The key function of the relief valve is to open and allow fluid to escape when the pressure exceeds a pre-set limit, also known as the relief pressure setting. This helps protect the system from damage due to excessive pressure build-up, which can occur due to various factors such as temperature increases, clogged lines, or pump failure.

In the context of fuel oil systems, if the pressure within the system surpasses the specified limitations, the relief valve will activate, releasing fuel oil to lower the internal pressure back to a safe level. This action is critical for the overall safety and integrity of the system, ensuring that high pressure does not lead to catastrophic failures or leaks.

Other scenarios, such as when pressure is below the limitations or fluctuates within the system, do not trigger the relief valve to discharge. The valve's purpose is solely to relieve excessive pressure, making the correct understanding of its operation crucial for maintaining safe operating conditions in mechanical and fuel oil systems.