How do you determine the gas capacity of a DOT cylinder?

To determine the gas capacity of a Department of Transportation (DOT) cylinder, the correct approach is to multiply the water capacity of the cylinder by 42%. This percentage is derived from the specific gravity of propane (or the gas being stored) in relation to water. Since the gas density is less than that of water, using this factor allows for an accurate conversion to find the usable gas capacity in gallons or pounds.

Water capacity is typically measured in pounds and once you have that figure, applying the 42% factor provides a reliable estimation of how much propane the cylinder can hold. This is crucial for safety regulations and ensuring that cylinders are filled to an appropriate capacity without exceeding safe limits.

Other methods listed might not yield the correct determination of gas capacity; for instance, merely multiplying the diameter by the height also does not account for the shapes and volume conversion necessary in cylinder calculations. Similarly, calculating volume using pressure and temperature is relevant in certain applications but does not directly provide the gas capacity of a cylinder. Lastly, using the total weight of the cylinder without factoring in the water capacity and the specific properties of the gas being measured would lead to inaccurate conclusions regarding usable gas capacity.