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Plant Engineering Calculator

Steam Flash Vessel Sizing Calculator — Diameter from Vapor Velocity

Estimate minimum flash-vessel cross-sectional area and diameter from flash-steam mass flow, vapor specific volume and allowable superficial velocity.

Inputs

Results

Vapor volume flow 0.236 m³/s
Minimum area 0.0236 m²
Theoretical diameter 173 mm
Diameter with area margin 190 mm

Formula

Qv=m·v/3600; A=Qv/V; D=sqrt(4A/π).

Worked example

500 kg/h flash steam at 1.7 m³/kg and 10 m/s needs about 0.0236 m² area, roughly 174 mm theoretical diameter.

Assumptions & limits

  • Allowable velocity must reflect separator internals, pressure and carryover requirements.
  • Add disengagement height, liquid holdup and nozzle sizing per design standard/OEM guidance.

FAQs

What does this Steam Flash Vessel Sizing Calculator calculate?

Estimate minimum flash-vessel cross-sectional area and diameter from flash-steam mass flow, vapor specific volume and allowable superficial velocity.

Which inputs matter most?

Use measured operating data where possible and keep pressure, temperature, flow, efficiency and tariff inputs on the stated basis. Intermediate outputs make the calculation auditable.

Can I use this for final equipment selection?

Use it for engineering screening and scenario comparison. Confirm final selections against OEM curves, steam/property tables, applicable codes and project design conditions.

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Last updated: 2026-09-17