Quick Q&A: What is the maximum pressure for airtightness testing, and does a higher test pressure always mean better results?

When it comes to quality inspection on automated production lines, many engineers face a common question:What is the maximum pressure for airtightness testing? Which scenarios are suitable for each pressure range? Does higher test pressure result in better testing accuracy and reliability?

In fact, the selection of pressure for gas testing has never been “The higher, the better", but rather to align with the product's actual operating conditions, mass production cycle times, and safety costs. In industrial mass production scenarios,Gas Testing EquipmentWith clear pressure classifications and application limits in place, selecting the appropriate pressure rating is far more valuable than blindly pursuing high pressure.

I. Pressure Classification and Application Limits for Industrial Gas Testing

Current Mainstream Production LinesAir tightness testing equipment, which can be divided into four major pressure-level ranges, each corresponding to specific application scenarios and technical characteristics:

Low-pressure detection (0–100 kPa)

This is the most commonly used mass-production pressure range in the consumer electronics industry, corresponding to a pressure of 0–1 bar. It is primarily used for water resistance and sealing tests on products such as smartphones, TWS earbuds, smartwatches, and small plastic enclosures. This rangeThe testing process is safe and efficient, capable of accurately detecting micro-leaks at the part-of-a-pico-liter level, while causing no damage to the workpieces. It is suitable for high-speed, high-volume production lines.The

Medium-Pressure Testing (100–500 kPa)

The standard operating range for automated production lines, corresponding to pressures of 1–5 bar, provides comprehensive coverage for leak testing of automotive connectors, headlights, solenoid valves, and various precision structural components. This rangeIt strikes a balance between seal strength verification and sensitivity in detecting micro-leaks, as well as between testing performance and mass production efficiency, making it the most widely used pressure rating in industrial applications.The

High-Pressure Testing (500 kPa–5 MPa)

Designed for pressures ranging from 5 to 50 bar, these products are suitable for applications requiring high sealing strength, such as new energy battery packs, industrial valve bodies, pressure vessels, and refrigeration system components. Made in Chinaairtightness meterThe high-pressure series of equipment from the leading brand JCGK now covers multiple pressure ratings, including 1 MPa, 2 MPa, 3 MPa, 4 MPa, and 5 MPa,Fully meeting the requirements for industrial-grade high-pressure sealing validation, it has already been widely implemented in high-end manufacturing sectors such as new energy and automotive components.The

Precision Die-Cast Parts 1.5 MPa High-Pressure Leak Tester

Custom Ultra-High Pressure (10 MPa and above)

This is found only in specially customized laboratory equipment and is not part of standard mass-production applications. Gas is a compressible medium; the higher the pressure, the greater the stored energy. In the event of a leak or pipeline failure, an extremely powerful force will be released. Therefore,Ultra-high-pressure gas testing requires extremely high-grade safety protection structures and explosion-proof designs, resulting in an exponential increase in equipment manufacturing costs; under mass production conditions, the return on investment is extremely low.The

II. Core Principles for Selecting Gas Detectors: Selection Is More Important Than Comparison

Many engineers have a misconception that higher pressure leads to more accurate testing. In fact, blindly increasing the test pressure can actually cause a series of negative effects, reducing the stability and reliability of the test:

1. Workpiece deformation causes results to be distorted: Plastic parts and thin-walled parts may expand and deform under excessive pressure, causing the stress conditions on the seals to deviate from actual operating conditions, which results in leakage data that does not accurately reflect the true sealing performance.
2. Systematic errors are amplified: The higher the pressure, the more significant the impact of errors caused by fluctuations in ambient temperature and minor pipe deformations, which in turn reduces the repeatability and consistency of the measurements.
3. Safety and Rising Costs: High pressure significantly increases the strength requirements for equipment valve assemblies, piping, and tooling, while also raising safety management costs on the production floor.

General Selection Formula

The industry-recognized guidelines for pressure selection are as follows:Test pressure ≈ 1.2 to 2 times the product's actual operating pressure

• Operating Pressure 20 kPa → Recommended Test Pressure 30–50 kPa
• Operating pressure: 100 kPa → Recommended test pressure: 150–200 kPa
• Operating pressure: 300 kPa → Recommended test pressure: 400–600 kPa
• Operating pressure: 1 MPa → Recommended test pressure: 1.2–2 MPa

This test range not only effectively simulates the product’s actual operating conditions and fully exposes sealing defects, but also prevents damage to workpieces and testing failures, making it the optimal choice for balancing testing effectiveness and mass production stability.

III. Why Gas Analysis Has Become the Mainstream Solution for Quality Control in Mass Production Lines

As the manufacturing industry undergoes an upgrade toward automation and digitization, airtightness testing has become a core component of quality control in mass production. Its key advantages are reflected in four areas:

1. Quantitative testing with controllable accuracy

Leak testing, based on detection principles such as pressure decay, differential pressure, and flow rate, can accurately quantify leak rates with a resolution as high as 0.001 ml/min. It can not only determine “Is there a leak?", and can more accurately measure "degree of leakage", providing data support for process optimization.

2. Native Adaptation for Automated Production Lines

Gas Testing EquipmentIt seamlessly integrates with industrial communication protocols such as PLC and Profinet, supports data upload to MES systems, parallel inspection across multiple stations, and automatic sorting and classification—all without any manual intervention. With an inspection cycle of just a few seconds per item, it perfectly matches the pace requirements of high-speed mass production lines.

3. Data traceability supports quality management

All inspection data can be stored, exported, and traced in real time. The system supports batch statistics and trend analysis, enabling companies to identify the root causes of fluctuations in production processes and helping them achieve the transition from “Conformity Determination"To "TheProcess Control"a quality upgrade."

4. Clean and energy-efficient, suitable for all industries

Leak testing requires only compressed air and electricity; it uses no additional consumables and causes no contamination or secondary damage to workpieces. It is suitable for industries with extremely high cleanliness requirements, such as consumer electronics, medical devices, and food packaging, and aligns with the trend toward green manufacturing.

IV. Mass Production LineGas Testing EquipmentKey Factors for Selection

selectionGas Testing Equipment...We cannot focus solely on single-point accuracy parameters; instead, we must evaluate the four core capabilities from the perspective of long-term production line operation:

1. Full-range pressure coverage capability: Give priority to equipment systems capable of covering multiple pressure ranges to meet the testing requirements of different products and avoid unnecessary costs resulting from duplicate purchases.
2. Automation Integration Capabilities: The equipment must be equipped with proven industrial communication interfaces that allow for rapid integration into existing production line automation systems and support future smart upgrades.
3. Long-term operational stability: In mass production environments, equipment typically operates continuously for 24 hours; therefore, the ability to suppress temperature drift, measurement repeatability, and the durability of core components are far more important than extreme precision achieved in laboratory conditions.
4. Localization Services and Customization Capabilities: Leak testing is a systematic process that requires supporting services such as custom tooling, parameter calibration, and post-sales commissioning. Local manufacturers, as the source of these solutions, offer response times and customization capabilities that are better suited to mass production needs.

Conclusion

Airtightness TesterIts core value is to provide stable, repeatable, and traceable quality control capabilities for sealing on mass production lines.The essence of pressure selection is to find the optimal balance between testing effectiveness, mass production efficiency, and safety costs.The

Shenzhen Jingchenggongke Technology Co., Ltd.(JCGK) offers a full range of airtightness testing solutions,Covers the full pressure range, from low-pressure consumer electronics to high-pressure industrial applications up to 5 MPa, with capabilities for custom tooling design and MES system integration...It can fully meet mass production quality control needs across various industries and at different stages, helping manufacturing companies establish an efficient, stable, and digital airtightness control system.

Original Statement:this paper was written byShenzhen Jingchenggongke Technology Co., Ltd.Written by the technical team, reproduced with attribution.Data sources: Precision Engineering internal test data and customer cases.