The restriction orifices are used for reducing fluid pressure and are designed somewhat different from the orifice plates that are used for measuring flow rates. They are designed to slip between the piping flanges.
While single restriction orifices are often sufficient to meet the requirements, there are situations where limitations arise due to process conditions making the single restriction orifices unacceptable. In such situations, use of multiple restriction in series is a better solution.
The foremost consideration for the case of multiple restriction is the pressure drop. This applies whether or not the fluid is liquid or vaporgas.Higher pressure drop implies higher velocities resulting in vibration and noise problems.

The restriction orifices are used for reducing fluid pressure and are designed somewhat different from the orifice plates that are used for measuring flow rates. They are designed to slip between the piping flanges.
While single restriction orifices are often sufficient to meet the requirements, there are situations where limitations arise due to process conditions making the single restriction orifices unacceptable. In such situations, use of multiple restriction in series is a better solution.
The foremost consideration for the case of multiple restriction is the pressure drop. This applies whether or not the fluid is liquid or vaporgas.Higher pressure drop implies higher velocities resulting in vibration and noise problems.