Leak testing is the process of checking a component or system for unintended passages of air, gas, or fluid. The goal is to ensure the product is hermetically sealed or within acceptable limits of leakage. Various industries rely on this testing to detect defects that could compromise performance or safety.
Several methods are available for leak testing, each with its own pros and cons:
Helium leak testing: The most accurate and sensitive method. It uses helium as a tracer gas and is ideal for detecting extremely small leaks, but it's expensive due to the cost of helium and the required equipment.
Bubble test (water immersion): A simple and low-cost method where the part is submerged in water, and air bubbles indicate the location of a leak. However, it's subjective, cannot quantify the leak, and is not automatable.
Pressure decay test: Involves monitoring pressure changes over time using sensors. It is cost-effective and avoids water contact but lacks accuracy and traceability.
Differential pressure test: This method improves accuracy by comparing the pressure between a reference volume and the test part, allowing for better detection of minor pressure changes.
ForTest designs its products based on air leak and flow testing systems using compressed air, overcoming the limitations of traditional methods by providing objective, repeatable, and traceable results. These systems can be seamlessly integrated into automated production lines and deliver real-time PASS/FAIL evaluations based on predefined thresholds.
Why Leak Testing and Leak Rate Matter?
Safety: In applications like airbags, brake systems, or medical devices, leaks can pose serious hazards.
Regulatory Compliance: Standards such as UNI 10903 set guidelines for leak testing, especially in the automotive and foundry sectors.
Product Reliability: Undetected leaks can lead to product failure, customer dissatisfaction, and costly recalls.
Process Optimization: By defining acceptable leak thresholds, manufacturers can ensure consistent quality without over-engineering parts.
Traceability and Quality Control: Modern testing instruments provide digital records, allowing manufacturers to trace and verify every test.
In some cases, legislation or standards (like UNI 10903) provide specific leak rate limits. In others, the customer defines the leak acceptance criteria based on the part's function. However, many scenarios require a combination of experience, test data, and technical evaluation to define the correct leak rate. Critical parameters include:
