Tank pressure is primarily controlled using pressure/vacuum relief vents. These vents are designed to automatically open and relieve excess pressure or vacuum, preventing damage to the tank.
Here's a breakdown of how this works:
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Pressure Relief: When the pressure inside the tank exceeds a pre-set limit, the pressure relief vent opens. This allows excess pressure to escape, typically by venting the contents (if they are safe to vent) into the atmosphere. This prevents the tank from over-pressurizing and potentially rupturing.
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Vacuum Relief: Conversely, if the pressure inside the tank drops below a pre-set limit, creating a vacuum, the vacuum relief vent opens. This allows air to enter the tank, equalizing the pressure and preventing the tank from collapsing.
Key Features of Pressure/Vacuum Relief Vents:
- Pre-set Limits: These vents are calibrated to open at specific pressure and vacuum levels.
- Automatic Operation: They operate automatically, without requiring manual intervention.
- Preventative Measure: They act as a safety measure to prevent tank damage.
- Venting: Often vent evaporated contents to atmosphere.
In summary, pressure/vacuum relief vents are crucial for maintaining safe operating pressures within tanks by automatically releasing excess pressure or vacuum.
