Check

A Check valve is a one-way valve allowing fluid to flow through one opening and leave through the other. The general purpose of this valve is to prevent backflow (flow in the opposite direction).

Check valves inherit the term “cracking pressure”. When the cracking pressure is reached, the valve will open. When the pressure drops below the cracking pressure and/or back-pressure occurs, the valve closes. The way a Check valve operates is ideal for preventing contamination from fluid flowing into separate services connected to a common header. This valve works automatically, and typically with no human or external control, such as a valve handle or stem.

Check valves have different configurations with the most common being the swing, tilting-disc, wafer, lift, and stop-check valves.