For what purpose is a two-way valve most commonly used?

A two-way valve is primarily used for isolating flow in a piping system. These valves can open or close to allow or prevent the passage of fluid, making them essential for controlling whether a particular section of the system is active or inactive. This function is crucial in various applications where maintenance or emergency shutdowns are needed.

When the valve is fully open, fluid can flow through without obstruction, and when it's closed, the flow is completely stopped, effectively isolating sections of the system. This characteristic is particularly important in ensuring safety and proper maintenance procedures in industrial applications.

While mixing fluids, diverting flow, and controlling flow rates are important processes managed by other types of valves or control systems, they do not match the primary and most straightforward purpose of a two-way valve, which is to isolate flow.