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Chemical Engineering vocabulary · Fluid Flow, Pumps and Piping

NPSH

Meaning in chemical engineering, with examples

abbreviationCommon term

In chemical engineering, NPSH means: Short for net positive suction head: the margin between the pressure at the pump inlet and the liquid's vapor pressure, expressed as meters of liquid.

In Turkish: net pozitif emme yüksekliği, NPSH

How it is used

Checked in every pump selection. NPSHa (available) comes from the system design; NPSHr (required) comes from the pump vendor's curve. NPSHa must be higher than NPSHr with a safety margin, or the pump will cavitate.

Example sentences

  1. With the tank at minimum level, NPSH available is only 2.1 m against 2.5 m required.

  2. Raising the suction vessel by two meters solved the NPSH problem.

Common collocations

  • NPSH available
  • NPSH required
  • NPSH margin
  • NPSH calculation
  • cavitationThe forming and violent collapse of vapor bubbles in a liquid when local pressure falls below its vapor pressure, usually at a pump inlet or across a valve.
  • pumpA machine that moves a liquid through pipes by adding pressure to it. Most plant pumps are centrifugal; others are positive displacement types such as gear or diaphragm pumps.
  • vapor pressureThe pressure of the vapor above a liquid when the two are in balance at a given temperature. It rises with temperature, and the liquid boils when it equals the surrounding pressure.
  • pressure dropThe loss of pressure as a fluid flows through a pipe, valve, filter, bed or piece of equipment, caused mainly by friction.

More terms: Fluid Flow, Pumps and Piping

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