5.1.1 Leaks and leak detection

What is a leak? A leak, also referred to as leakage, enables a substance to flow toward a pressure gradient. Expressed in simpler terms, leaks are small holes through which gases or liquids flow from the side of higher pressure to the side of lower pressure. This can involve simple, harmless leaks, such as a dripping water faucet, or hazardous toxic substances that escape through leaks.

Any number of technical products will not function, or will not function for an adequate period of time, if they have leaks. Examples include: The refrigerant circulation system in refrigerators, air conditioning systems in cars, automobile tires, automotive fuel tanks or home fuel oil tanks, as well as distillation systems in the chemical or pharmaceutical industries. In many cases, the leak-tightness of machines and systems in the production process is an indispensable prerequisite for the quality of the manufactured products

Returning to the original definition of a leak, we thus find that it is impossible to completely prevent substances from flowing through a wall. The term „tight” therefore refers to the requirements of the respective machine, plant or vessel, and must be quantified accordingly.