CDL Tanker Endorsement Practice Exam

Why might you not be able to fill the tanks completely?

1. Some tanks have built-in safety limits

2. The liquid may expand when warm

3. There could be a weight restriction

4. Both of the above are true

The correct answer is: Both of the above are true

Filling tanker trucks completely is a careful process influenced by several factors that ensure safety and compliance with regulations. Among these, built-in safety limits in the tanks play a crucial role. These limits are designed to prevent overfilling, which can lead to dangerous situations such as spills or leaks. The tanks are engineered with specific capacities that account for various factors, including the thermal expansion of liquids. In addition, liquids can expand when warmed, which is another reason why complete filling is not always feasible. If the liquid in the tank is filled to its full capacity in cooler temperatures, it may expand as temperatures increase, leading to overflow or spillage if the tanks are filled completely. Weight restrictions also factor into the decision on how much liquid can be carried. Tankers have specific weight limits based on vehicle specifications and road regulations. Filling the tanks to capacity could exceed these weight limits, making it unsafe or illegal to operate the vehicle on public roads. Thus, the correct answer encapsulates both the necessity of adhering to safety limits and the considerations of thermal expansion of liquids, along with the legal weight restrictions that govern tanker operations.