What type of valve allows the bypass of fluids to limit pressure in a system?

The relief valve is specifically designed to allow excess pressure to escape from a system, helping to prevent potential damage due to overpressure conditions. When the pressure in the system exceeds a predetermined level, the relief valve automatically opens, bypassing some of the fluid to a safe area, which limits the overall pressure within the system.

This functionality is critical in many applications, particularly in fire apparatus and other pressurized systems, where maintaining safe operating pressures is vital for safety and equipment integrity. In contrast, the other types of valves do not perform this function: a check valve prevents backflow but does not help with pressure regulation, a butterfly valve is used for flow regulation but not specifically for pressure relief, and a gate valve is primarily designed for on/off control rather than pressure management.