Step-by-Step Partial Pressure Blending at the Fill Station

The Gas Blender calculates precise fill sequences using partial pressure blending — the standard method for mixing nitrox and trimix at dive shops and fill stations. You tell it what mix you want, what pressure you want in the cylinder, and what banks you have available. It tells you exactly how much of each gas to add, and in what order.

The tool handles complex scenarios: topping off cylinders that already contain a residual mix, blending with multiple bank configurations (pure O2 + air, O2 + He + air, or any combination), and accounting for real gas behavior at high pressures using Van der Waals compensation.

Each blending plan shows clear, numbered steps: "Fill O2 to X bar, then He to Y bar, then top with air to Z bar." Set up your bank volumes and working pressures once, and reuse them across every fill — no re-entering data between dives.