In industrial production.Leakage rate is an important indicator of a product's airtightness.It is like a "health checkup report" that accurately reflects the sealing status of the equipment and provides timely warning of potential safety hazards and quality risks. A small leakage can lead to energy waste, safety accidents and even environmental pollution. ThereforeIt is crucial to know how to calculate the leakage rate.
This article will introduce you to common leakage rate calculations in an easy-to-understand format and provide practical formulas to make them easy to understandairtightness testingThe core technology of the
I. Basic concepts of leakage rate
Leakage rate is the volume or mass of gas that escapes the sealed system per unit of time, usually expressed in the following units:
- Milliliters per minute (ml/min)
- Standard cubic centimeters per minute (sccm)
- Pa-meter per second (Pa-m³/s)
- Milligrams per hour (mg/h)
II. Common methods of calculating leakage rates
1. Pressure decay method
The pressure decay method monitors the change in pressure over time in a sealed system., indirectly inferring leakage rates.
Working Principle: Fill the sealing system with a gas at a certain pressure and record the pressure decay per unit of time. The greater the pressure decay, the higher the leakage rate.
Calculation formula:
Q=(ΔP⋅V)/Δt
Among them:
- Q: Leakage rate (Pa-m³/s)
- ΔP: Pressure decay value (Pa)
- V: volume of the sealing system (m³)
- Δt: test time (s)
appliance: Suitable for overall sealing test, widely used in automotive parts, valves and other fields.
2. Mass flow approach
Mass flow method for direct measurement of the mass flow of a leaking gasThe flowmeter is a high-precision flowmeter that can be used for measurement.
Calculation formula:
Q=m/t
Among them:
- Q: Leakage rate (kg/s or g/h)
- m: mass of gas leaking (kg or g)
- t: measurement time (s or h)
appliance: Suitable for large leakage scenarios, such as leakage detection of pressure vessels and pipelines.
3. Tracer gas method
The tracer gas method is performed by injecting a specific tracer gas (e.g. helium) into a sealed system.The gas detectors are used to track leaks and their rate of leakage.
Advantage:
- Capable of detecting extremely small leaks (micron level)
- Particularly suitable for products with complex structures, such as aerospace components
4. Pressure drop conversion method
The pressure drop value conversion method combines pressure decay with the measured product volume to accurately quantify the leakage rate through a standard conversion formula.
Calculation formula:
Q=∆𝑃/𝑃o ∙𝑉𝑤∙60/𝑡
Among them:
- Q: Leakage rate (ml/min or sccm)
- Δ𝑃: actual leakage pressure drop (Pa)
- 𝑃o: standard atmospheric pressure (101325 Pa)
- 𝑉𝑤: volume of product measured (ml)
- 𝑡: Detection holding time (s)
Example: Assuming an actual pressure drop of 50 Pa, a product volume of 100 ml, and a detection time of 10 seconds, the leakage rate is calculated as follows:
Q=(50÷101325)×100×(60÷10)≈0.30ml/min
appliance: The method is suitable for gas-tight holding pressure testing and can quickly and accurately quantify the leakage rate, which is one of the commonly used inspection tools in industry today.
5. Foam method
The foam method is the traditional means of leak detection, in which a foam solution is applied and the production of air bubbles at the leak point is observed.
Operational Steps:
① Apply foam solution to the surface of pipes, valves or equipment.
② Foam is generated at the leakage point.
(iii) Estimate the leakage rate based on the expansion rate and size of the foam.
specificities: The method is simple and intuitive, but it is difficult to quantify and less accurate, and is gradually being replaced by other methods.
III. Free experience with the leak rate calculator
Leakage rate calculations may seem boring, but in fact they are the "clairvoyance" that ensures product quality and environmental safety. In the actual testing process, the complexity of the leak rate calculation is often daunting.
To help you calculate leakage rates quickly and accurately, thePrecision Engineering AirtightnessLaunched a free leak rate calculator!
Operating Instructions:
Follow "Precision Engineering Airtightness"Official Public Number
Click "One Click Conversion" in the lower right corner of the menu bar to enter the "Airtight Leakage Calculator" Input the relevant parameters and get the leakage rate result immediately.
Featured Function:
✅ Pressure unit converter that supports automatic conversion of 12 common pressure units
✅ Airtight Leak Rate Calculator, supports automatic calculation of pressure drop to leak rate
✅ Leak Rate Pressure Drop Calculator, supports automatic calculation of leakage values to pressure drop values
IV. Summary
Accurate calculation of leakage rates is an important safeguard for quality control of industrial products. Whether you are a technician or an industry expert, mastering the calculation of leakage rates can help you.
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