What are the two types of mechanical injectors?

The two types of mechanical injectors refer to their physical design and operational characteristics. Flanged injectors typically have flanges that allow for easier attachment to various piping systems, enhancing their utility in industrial applications. Cylindrical injectors usually have a more streamlined, round design that can provide more consistent flow characteristics and better fit within specific systems.

In contrast, electronic and manual designations focus on how the injectors are controlled rather than their physical configuration. Rotary and fixed refer to the operational mechanics, indicating how the injector operates but not necessarily distinguishing between two primary types. Direct and indirect classifications imply how the injectors deliver fuel or other fluids, but again, do not represent the fundamental mechanical design types.

Thus, the distinction between mechanical injectors is most accurately characterized by their physical form as flanged and cylindrical, making this the correct answer.