There are some differences between DOT containers and ASME tanks that impact evacuation procedures. Which statement does not belong?

There are some differences between DOT containers and ASME tanks that impact evacuation procedures. Which statement does not belong?

• A. DOT containers may be transported filled to their legal limit
• B. Not all DOT containers are equipped with vapor return fittings
• C. DOT containers are usually equipped with liquid evacuation valves
• D. Not all DOT containers are equipped with float gauges

Answer: (C)

When thinking about evacuation procedures, the key is how the container’s design affects how propane can be removed safely. DOT cylinders and larger ASME tanks differ in their valve setups and instrumentation, which changes what you can do during an evacuation. DOT containers are generally designed for portable use and gas withdrawal through a standard valve. They typically don’t have a separate liquid evacuation valve. Evacuation from these cylinders is done via the regular gas valve and venting paths, not by tapping a dedicated liquid-outlet. This makes the idea of a “liquid evacuation valve” on a DOT container inaccurate as a common feature, and that’s why the statement about DOT containers usually being equipped with liquid evacuation valves doesn’t fit with the other points about how DOT containers differ from ASME tanks. The other statements reflect real differences you’d encounter: some DOT containers may or may not have vapor return fittings, and some may or may not have float gauges, which can affect how you manage vapors and liquid levels during evacuation. Also, DOT containers can be transported at their legal fill limits, which is a practical consideration during load and move operations. So, the non-fitting statement is the one claiming DOT containers are usually equipped with liquid evacuation valves, because that feature is more characteristic of certain ASME tanks, not the typical DOT cylinders.

When thinking about evacuation procedures, the key is how the container’s design affects how propane can be removed safely. DOT cylinders and larger ASME tanks differ in their valve setups and instrumentation, which changes what you can do during an evacuation.

DOT containers are generally designed for portable use and gas withdrawal through a standard valve. They typically don’t have a separate liquid evacuation valve. Evacuation from these cylinders is done via the regular gas valve and venting paths, not by tapping a dedicated liquid-outlet. This makes the idea of a “liquid evacuation valve” on a DOT container inaccurate as a common feature, and that’s why the statement about DOT containers usually being equipped with liquid evacuation valves doesn’t fit with the other points about how DOT containers differ from ASME tanks.

The other statements reflect real differences you’d encounter: some DOT containers may or may not have vapor return fittings, and some may or may not have float gauges, which can affect how you manage vapors and liquid levels during evacuation. Also, DOT containers can be transported at their legal fill limits, which is a practical consideration during load and move operations.

So, the non-fitting statement is the one claiming DOT containers are usually equipped with liquid evacuation valves, because that feature is more characteristic of certain ASME tanks, not the typical DOT cylinders.