What happens when pressure is not bled off before opening a pipe system?

When pressure is not bled off before opening a pipe system, it poses a significant risk, particularly of an explosion. This is primarily because pressurized systems contain gases or liquids that can be under high pressure, which can rapidly expand when a sealed system is opened suddenly. If the pressure is not adequately relieved, the force generated can be sufficient to cause violent ejection of materials, leading to a dangerous situation.

This explosive potential is a critical safety concern in various industries, especially those dealing with gases or volatile fluids. The sudden release of pressure can result in hazardous projectiles, serious injury, or catastrophic failure of the pipe system itself. Hence, proper procedures dictate that pressure must be safely bled off before any operation involves the opening of a pipe to ensure safety and prevent accidents.