Different orifice plates are:

1. Concentric

2. Segmental

3. Eccentric

- Concentric: These plates are used for ideal liquid as well as gases and steam service. Concentric holes are present in these plates, thats why it is known as concentric orifice.

- Segmental: This plate has hole in the form of segment of the circle. This plate is used for colloidal and sherry flow measurement.

- Eccentric: This plate has the eccentric holes. This plate is used in viscous and sherry flow measurement.