APCO Clean Water Air Release Valves (ARV)

The APCO Clean Water Air Release Valves (ARV) function to release air pockets that collect at each high point of a pressured pipeline, and are essential for pipeline efficiency and water hammer protection. Air Release Valves are available in a wide variety of orifice sizes and materials of construction to meet a wide range of applications.

Air in a pressurized closed-pipeline system can have many negative effects. When air is present in a hydraulic pipeline, flows are erratic, unpredictable and have high head losses. An air pocket will decrease the cross-sectional area and increase frictional pressure loss. The combined loss for two-phase flow (air and water) is always greater than the pressure loss for each phase flowing alone. Thus, air in a pipeline increases system flow resistance and increases system head against which pumps must operate.

Air in piping tends to collect at high points in the line when flow velocities are low. If the air pocket formed is large, part of it will be removed when the velocity increases. This partitioned air may or may not go through the system, depending on velocity, pipe size, and pipe down-slope. Air may only move into the sloping straight section and then return to the summit when the velocity decreases.

While it is impossible to totally prevent accumulation of air (or gases) within the piping system, the volume can be greatly minimized by installing APCO Air Release Valves on pipeline high points.