It is essential to have air- release valves when designing a system piping. As air pockets accumulate in a system, the air -release valves will vent the pockets. According to an article by Hydraulic Institute, “If the pipeline is fairly flat and the inside surface of the pipe is very rough, or if the pipeline slopes downward, the fluid velocity may not be sufficient to keep the bubbles moving”. This can cause pockets of air to form at the high points and will begin to effect the liquid flow areas.
Click here to read the full article by Hydraulic Institute at PumpsAndSystems.com.