What is the name of an orifice plate with a round opening centered in the middle?

An orifice plate with a round opening that is centered in the middle is known as a concentric orifice. This design is characterized by its symmetrical shape, which allows for uniform flow through the opening, thereby providing an accurate measurement of flow rate. The central positioning of the opening ensures that the fluid flows evenly and minimizes turbulence, leading to reliable performance in flow measurement applications.

In contrast, other types of orifice plates, such as eccentric orifices, have openings that are offset, which can introduce variability in the flow measurement due to the uneven distribution of fluid. This design serves specific purposes but does not provide the straightforward, consistent flow characteristics associated with a concentric orifice. Understanding these distinctions helps in selecting the appropriate type of orifice plate for specific flow measurement tasks and enhances the accuracy and reliability of system operations.