Dear All
I have assignment to convert the gun barrel tank into water holding tank due to the existing holding tank maintenance. The gun barrel tank has the same capacity as existing holding tank (500 BBL).
Existing gun barrel tank has interface line @ tank outlet nozzle and Blanketing gas (fuel gas as blanketing gas) connection.
Existing Gun barrel tank has VPSV (vacuum relief valve) @ the top of the tank.
Q1. To convert the gun barrel tank into holding tank shall I remove the interface line and why.
I propose to remove the interface line because there is no interface (Oil & Water) and the outlet is become the suction of the centrifugal pumps so there is some chances to infuse the blanketing gas (FG) into the pump suction line.
But there is an argument that due to the level in the tank water will be raised in the interface line so the chance of blanketing gas infusion is not possible.
Q2. Shall I install the VPSV for the vacuum protection of the tank.
I have confusion that due to the VPSV, air (oxygen) will be in-breath and tank has blanketing gas (FG) which has Air fuel mixture in the tank.
I need your suggestion and views about my understanding and decision. see attachment for more understanding. RED line shows the interface line which is currently isolated with the tank outlet nozzle but will be connected during commissioning.
Regards