Vacuum Pump Capacity Calculation Xls Jun 2026

This formula determines the flow rate needed to empty a clean, dry vessel from atmospheric pressure down to your target pressure within a specific time limit.

If your process involves evaporating liquids (like in distillation), the pump must handle the resulting vapor mass flow. Mechvactech How to Calculate Vacuum Pump Capacity | Step-by-Step Guide vacuum pump capacity calculation xls

"Good," Elias nodded. "Now, for a vessel this size, operating at low vacuum, we can estimate the leakage based on the internal volume. In cell B6, type 'Leakage Factor'. Since our joints are old and rusty, use a conservative factor. Let's say 0.2 kg/hr per m3." This formula determines the flow rate needed to

A two-stage rotary vane pump (30 m³/h ≈ 8.3 L/s for roughing) plus a Roots blower (300 m³/h ≈ 83 L/s) to handle the outgassing load at low pressure. "Now, for a vessel this size, operating at

(with pipe/valve conductance)

| | Description (Typical Units) | Purpose | | :--- | :--- | :--- | | V | Total chamber/system volume (m³, ft³) | Volume to be evacuated for calculating time | | Initial Pressure (p₁) | Starting absolute pressure (mbar, Torr) | Usually atmospheric pressure (1013 mbar / 760 Torr) | | Final Pressure (p₂) | Target absolute pressure (mbar, Torr) | Dictated by your process requirements | | Evacuation Time (t) | Max allowable pump-down time (min, s) | A key process constraint for driving pump size | | Leak / Gas Load (Q) | Total inflow into the system (kg/h, lb/h) | From seal leakage or outgassing, a critical load on the pump | | System Type | Dropdown (Welded, Flanged, etc.) | Estimates typical leakage rates based on experience tables | | Pump Type | Dropdown (Liquid Ring, Rotary Vane, Claw, etc.) | Applies correct pump-specific curves and limitations |

Program these exact Excel strings into your output cells to calculate pump sizes automatically. 1. Net Evacuation Pumping Speed ( = (B3 / (B6 / B11)) * LN(B4 / B5)