Should the worst happen, and your tank be engulfed by an external fire or there be an abnormal overpressure event within the tank, it is vital that the tank has the facility to relieve the excess pressure that cannot be vented through the standard breather valve. This preventing the catastrophic possibility of your tank rupturing and causing further danger to life and the environment.

This is done via an emergency vent or emergency manway, under normal operating conditions this remains closed and only opens in an emergency case.

It is important when sizing an emergency vent that all the conditions are considered including site location, tank size, insulation on the tank as well as the media stored. This is done using the industry standard API 2000 calculation.

In addition to the possible damage caused by an abnormal overpressure event, it is important to consider the damage that can be caused by an over vacuum event, that can implode your tanks. To overcome this problem Flexachem UK can supply emergency manways that include the option for emergency vacuum relief built in, limiting the risk to you, your staff and your plant.