Burner Fuel Changeover Pressure Calculator

Hamza Gujjar Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer Last updated: July 26, 2026

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Burner Fuel Changeover Pressure Calculator

Switching a burner between two different fuel gases through the same fixed orifice - a common scenario when converting equipment between propane and natural gas, for example - requires a different supply pressure to deliver equivalent heat input.

The Formula

P2 = P1 × (HV1/HV2)² × (SG2/SG1)

Worked Example

Converting from a gas at 2.5 kPa with 38 MJ/m³ heating value and 0.6 specific gravity, to a gas with 93 MJ/m³ heating value and 1.5 specific gravity:

P2 = 2.5 × (38/93)² × (1.5/0.6) ≈ 1.04 kPa

How to Use This Calculator

  1. Enter the original gas's supply pressure, heating value, and specific gravity.
  2. Enter the new gas's heating value and specific gravity.

Important: this is a theoretical starting estimate only - always verify actual burner conversion pressures against the manufacturer's conversion kit specifications before commissioning.