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Plant Engineering Calculator

Flash Steam Percentage Calculator — Condensate Letdown & Flash Flow

Calculate flash-steam fraction and mass flow from high-pressure condensate liquid enthalpy and low-pressure saturated liquid/latent enthalpy.

Inputs

Results

Flash fraction 15.20 %
Flash steam 152.0 kg/h
Remaining condensate 848.0 kg/h
Flash ratio 0.1520 kg/kg feed

Formula

x=(hf,high−hf,low)/hfg,low; mflash=x·mcond.

Worked example

With hf,high=762, hf,low=419 and hfg,low=2257 kJ/kg, about 15.2% of saturated condensate flashes after letdown.

Assumptions & limits

  • Enter validated steam-table enthalpies for both pressure states.
  • Assumes adiabatic throttling and saturated liquid upstream; subcooling changes the result.

FAQs

What does this Flash Steam Percentage Calculator calculate?

Calculate flash-steam fraction and mass flow from high-pressure condensate liquid enthalpy and low-pressure saturated liquid/latent enthalpy.

What should I verify before using the result?

Check units, operating point, measured site data and OEM limits. This calculator is a transparent screening tool, not a substitute for equipment selection or code-required design.

Why are intermediate results included?

Intermediate values expose the engineering chain so you can audit assumptions, compare scenarios and catch unrealistic inputs.

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Last updated: 2026-09-17