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Pulsation Limit

INERTANCE perform Pulsation study as per related API standards for reciprocating compressor and pump. Piping system has been designed against unbalance shaking force by acoustic energy, and the pulsation limit (Pulsation criteria) has been evaluated such as pulsation level, Separation margin against mechanical resonance, vibration criteria (Vibration criteria) for piping system, pressure drop.

Pulsation Level

The unfiltered peak to peak pulsation level at the compressor cylinder flange shall be limited to the lesser of 7% as percentage of average absolute line pressure. However, the higher limits may be agreed on by purchaser and manufacturer, where the maximum pulsation level exceed this pulsation limit for reasonable modification for pulsation control.

Pulsation limit and pressure drop
Pulsation limit and pressure drop

 

Separation Margin

The minimum mechanical natural frequency of piping system element shall be designed to be greater than 2.4 times maximum rated speed. In addition, the predicted mechanical natural frequency shall be designed to be separated from significant excitation frequency by at least 20%.

Separation Margin
Separation Margin

 

Pressure Drop (Pressure Loss)

The pressure drop for each operating case through a pulsation suppression device shall not be exceed 0.25% of average absolute line pressure. Pressure drop may be exceeded as results of the preferred solution to piping resonance problems, which should be mutually agreed between purchaser and manufacturer.

Vibration Criteria (Vibration Limit)

The predicted piping vibration magnitude shall be limited to the design level as shown in below figure. The constant allowable vibration velocity of approximately 32 mm/s peak to peak for frequency between 10 and 200 Hz. However, these values should not be used as filed acceptance criteria.

Vibration criteria (Vibration Limit)
Vibration criteria (Vibration Limit)

 

INERTANE has a capability regarding noise and vibration engineering, and our experts are familiar with assessment of Pulsation criteria. For further information, contact us at (admin@inertance.com).