What are the different types of orifice plates and state their uses?

The different types of orifice plates are:

1. Concentric.
2. Segmental.
3. Eccentric.
4. Quadrant Edge.

Concentric: The concentric orifice plate is used for ideal liquid as well as gases and steam service. This orifice plate beta ratio fall between of 0.15 to 0.75 for liquid and 0.20 to 0.70 for gases, and steam. Best results occur between value of 0.4 and 0.6. Beta ratio of the orifice bore to the internal pipe diameters.

(45º beveled edges are often used to minimize friction resistance to flowing fluid.)

Eccentric: The eccentric orifice plate has a hole eccentric. Use full for measuring containing solids, oil containing water and wet steam. Eccentric plates can be used either flange or vena contracts taps, but the tap must be at 180º or 90º to the eccentric opening.

Eccentric orifices have the bore offset from center to minimize problems in services of solids-containing materials.

Segmental: The segmental orifice plate has the hole in the form segment of a circle. This is used for colloidal and slurry flow measurement. For best accuracy, the tap location should be 180º from center of tangency.

Segmental orifices provide another version of plates useful for solids containing materials.

Quadrant Edge: It common use in Europe and are particularly useful for pipe sizes less than 2 inches.

Quadrant edge orifices produce a relatively constant coefficient of discharge for services with low Reynolds numbers in the range from 100,000 down to 5,000.