What does maintaining pressure mean in the airtightness test of pressure vessels?
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As the title suggests, I understand that \"pressure holding\" means maintaining a constant pressure. What I want to ask is: if the container isn’t airtight and the pressure gradually decreases, does this mean that in such a case \"pressure holding\" requires continuous inflation of the container? To maintain the pressure inside the container at a certain value.
Definition: A test in which compressed air is introduced into a chamber or container and held at a specified pressure for a set period of time; leaks are detected by applying soapy water or by measuring the drop in pressure. OP, you don’t seem to have a very deep understanding of this concept of airtightness! Why is a leak test necessary? It is to ensure that there are no leaks in the container. A leak test is used to achieve this goal; it is required that there be no trace of leakage in the equipment. If you can’t even maintain a proper pressure level, then the purpose of the leak test is lost!
Furthermore, the 1999 version of the regulatory standards explicitly stipulates that continuous pressurization cannot be used to maintain a constant pressure.
A rapid drop in pressure indicates the presence of a significant gap (some area that hasn’t been welded or has cracks). If the pressure remains stable under such conditions, it is possible for the cracks to widen, leading even to an explosion and safety accidents. If there is indeed a rapid drop in pressure, one should be able to hear the sound of air leaking. The proper approach is to locate the source of the leak and take corrective action. Or simply scrap it
In my opinion, holding pressure is mainly to facilitate the detection of any leakage points.
Holding pressure does not mean maintaining a constant pressure; it mainly refers to whether there is any change in pressure over a certain period of time. It is usually described as: hold the pressure for 20 minutes, and see by how much the pressure drops, or whether it remains unchanged, etc
There are two purposes for maintaining pressure: 1. To stop stamping under a certain pressure. Check whether the pressure has decreased over a certain period of time. (Check for any minor leaks.) 2. Maintain pressure in the container and use a gas-tightness tester to detect any minor leaks as well as their exact locations.
Check GB150 or the «Technical Code for Safety Inspection of Pressure Vessels»； You don’t understand either the definition or the purpose!