AGA-3 is a small application that will help you size orifice plates for given design conditions, find pressure drop for a given flow, or flow for a given pressure drop. The standard AGA-3 ( API-2530: 1991) is originally designed for gas orifices. In this program it's also used for liquid orifices.

The programs let you calculate the following orifice-types:

Gas Orifice

Liquid Orifice

Restriction Orifice - Gas

Restriction Orifice - Liquid