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NPSH is an acronym for Net Positive Suction Head. It shows the difference, in any cross-section of a generic hydraulic circuit, between the pressure and the liquid vapor pressure in that section.
NPSH is an important parameter, to be taken into account when designing a circuit : whenever the liquid stagnation pressure drops below the vapor pressure, liquid boiling occurs, and the final effect will be cavitation: vapor bubbles may reduce or stop the liquid flow. Centrifugal pumps are particularly vulnerable, whereas positive displacement pumps are less affected by cavitation, as they are better able to pump two-phase flow (the mixture of gas and liquid), however, the resultant flow rate of the pump will be diminished because of the gas volumetrically displacing a disproportion of liquid.

Tanya – Dwi Andik Harianto@gunanusa

Teman milist

Mohon pencerahannya mengenai penentuan NPSH suatu pompa.

Faktor apa saja yang harus diperhatikan selain letak/jarak vertikal pompa.

Terhadap fluida dan routing pipa.

Apakah ada perhitungannya dan standar apa yang dipakai.

Tanggapan 1 – Ari Firmansyah

Mas Andik,

NPSH yang dimaksud apakah NPSH available (NPSHa) atau NPSH required (NPSHr)?

NPSHa ditentukan berdasarkan faktor yang anda sebutkan, jarak vertikal (static head), pressure drop sepanjang suction piping dan vapor pressure at maksimum operating temperatur dari fluid yang akan dipompa dan operating pressure at suction.

NPSHr anda bisa lihat di katalog pompa yang akan digunakan, piping and equipment layout sedemikian, sehingga NPSHa > NPSHr.

Thanks

Tanggapan 2 – Punjung Sasmito

Mungkin pakdhe GPSA (section 12) ato eyang API 14 E appendix A2 bisa membantu sampeyan.

Tanggapan selengkapnya dari rekan-rekan Mailing List Migas Indonesia dapat dilihat dalam file berikut:

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