This professional-grade tool calculates the oil carryover rate in parts per million (PPM) for any oil-injected rotary screw compressor. By tracking oil consumption against compressed air output, maintenance teams can accurately diagnose the health of the air-oil separator and scavenging system.
Key Features:
- Multi-Unit Support: Seamlessly handles both Imperial (CFM/Gallons) and Metric (m3/min/Litres) measurements.
- Precision Mass Balance: Uses a standard air density of 1.225\ kg/m3 and a default oil specific gravity of 0.87 for laboratory-grade accuracy.
- Instant Diagnostics: Provides immediate feedback based on manufacturer standards, identifying whether a system is Optimal, Cautionary, or Critical.
3. Why Measure PPM?
In a rotary screw compressor, the air-oil separator is responsible for removing lubricants before the air enters the distribution lines.2 Measuring the PPM is vital because:
- Normal Performance: A healthy separator should maintain a carryover between 1 and 3 PPM.
- Warning Signs: Results between 4 and 8 PPM often indicate a clogged scavenge line or an ageing separator element.
- Critical Failure: Carryover exceeding 10 PPM suggests a ruptured separator, overfilled oil sump, or malfunctioning Minimum Pressure Valve (MPV).
4. How to Use the Calculator
- Flow Rate (Q): Enter the rated capacity of your compressor (e.g., 100 CFM).
- Running Hours (T): Input the total clock hours since the last time you added oil.
- Oil Consumption (V): Enter the exact amount of oil added to reach the “Full” mark.
- Oil Density: Leave at 0.87 unless you are using a specialised lubricant with a different specific gravity.