The static pressure is applied uniformly in all directions, while the velocity pressure is applied only in the air flow direction. This makes it difficult to directly measure the velocity and pressure in the pipeline.
Simply put, because the static pressure is also pushing in the direction of the air flow, the static velocity pressure cannot be measured. In fact, the velocity pressure is calculated by measuring the pressure perpendicular to the air flow (static pressure) and the pressure parallel to the air flow (total pressure).
Static pressure and velocity pressure are converted to each other. The size of each pipe depends on the local pipe cross-section velocity that determines the flow rate.
The pressure change in the pipeline is affected by the following: constant cross-sectional area: the total loss is equal to the static loss. In the diverging section (the pipeline size increases): the velocity pressure increases, the total pressure decreases, the static pressure may increase (static moisture regain), and the convergence section (the pipeline size decreases): the velocity pressure increases along the flow direction, and the total pressure and static pressure decrease.
Due to friction and turbulence losses, the total pressure usually drops along the flow. It is very common for Changzhou spiral duct contractors to use the terms of "static pressure", "velocity pressure" and "total pressure". The term "static pressure" is usually used for fan selection; "speed pressure" is used to measure CFM in the system, and "total pressure" is used to find the speed pressure. The total pressure determines that it must be provided to the system. 上一篇：通風管道中風管與支吊架的安裝闡明