I would like to ask for information regarding the use of stainless steel floating disks behind dome tanks
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I would like to ask: after installing a stainless steel floating disk behind a dome tank, should the breather valve be put into use? Is it necessary to monitor the concentration of gaseous explosive gases in the upper space of the floating pad? The material is petroleum products (naphtha, gasoline, diesel, etc.)
If no nitrogen seal is used, the breather valve should be removed, and vents should be provided around the tank wall； If a nitrogen seal is installed, the breather valve should be in use.
The nitrogen sealing system is no longer needed; blind flanges should be installed on the pipelines. Are there any national standards in this regard? Thank you!
After the storage tank is converted from a vaulted tank to an internal floating roof tank, the changes in the tank accessories can be referred to SH3007-2014. With the nitrogen sealing system now disabled, it is a typical internal floating roof tank; the breather valve has been removed, and a vent hole equipped with a flame arrester is installed on the top of the tank. Vent holes are also provided around it to allow communication with the atmosphere and facilitate gas flow. As a result, explosive gases cannot accumulate inside the tank, so there is no need to monitor their concentration. Hope this helps!
When vent holes are created in the wall of a dome tank, the breather valve loses its function
The nitrogen sealing system was originally connected directly to the top of the tank. However, in internal floating roof tanks, the floating disk can sink when the liquid level is below it; gaps between the liquid level and the floating disk allow air to enter, resulting in the formation of mixed flammable and explosive gases. Therefore, after the modification, it was decided to install nitrogen pipelines at the bottom of the tank.