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Chemical Engineering vocabulary · Thermodynamics and Physical Properties

Vapor pressure

Meaning in chemical engineering, with examples

nounCore term

In chemical engineering, vapor pressure means: The 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.

In Turkish: buhar basıncı

How it is used

Used in distillation design, storage, pump NPSH checks and safety. Volatile liquids have a high vapor pressure. Engineers estimate it with the Antoine equation or read it from data tables and simulators.

Example sentences

  1. Butane has a high vapor pressure, so it is stored in pressurized spheres.

  2. At 60 °C the vapor pressure of the solvent is too high for this pump's suction.

Common collocations

  • high vapor pressure
  • Reid vapor pressure
  • vapor pressure curve
  • saturation pressure
  • boiling pointThe temperature at which a liquid's vapor pressure equals the surrounding pressure, so that it boils. It goes down under vacuum and up at higher pressure.
  • vapor-liquid equilibriumThe state in which a liquid and its vapor exist together with no net change, each with a fixed composition. It is the basis for designing distillation and flash separations.
  • NPSHShort 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.
  • flash pointThe lowest temperature at which a liquid gives off enough vapor to catch fire briefly when a flame or spark is brought near it.
  • dew pointThe temperature at which a gas or vapor mixture, when cooled at constant pressure, starts to form the first drops of liquid.

More terms: Thermodynamics and Physical Properties

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