Liquid tank inspection including device for launching submersible

An apparatus comprising:

• a modular dispensing tube having a top side valve, a launching chamber sized to accommodate a robotic drone inserted through the top side valve, and a bottom side valve structured to release the robotic drone from the launching chamber,
• the modular dispensing tube also including an air release passageway in fluid communication with the launching chamber and having a purge valve structured to have an open position in which the air release passage allows air to escape from the launching chamber during a pre-launch liquid fill event, the purge valve also structured to have a closed position to discourage the escape of liquid from the launching chamber,
• wherein the modular dispensing tube is configured as a portable dispensing tube having a connection surface structured to releasably engage with a liquid fluid tank to insert the robotic drone into the liquid fluid tank, and to be disengaged to permit portable movement of the modular dispensing tube to be used on another liquid fluid tank.