The tanker is the liquid carrier. Only a tanker or the hull can take liquids aboard (fuel, water, hydrogen, oxygen and coolant), and only a tanker or the hull can hand fuel to another ship. It has a very large fuel tank and a hold for the rest.
A Shipyard builds it from tanks, a pump, seals and a thruster. It is a destroyer, so it docks at a cruiser-size station such as a Port or a Forward HQ, not at an Outpost.