New York Low Pressure Boiler COF Practice

When 1 pound of water is turned into steam, how much does its volume increase?

1. 10 times

2. 100 times

3. 1000 times

4. Over 1600 times

The correct answer is: Over 1600 times

When 1 pound of water is converted into steam at atmospheric pressure, its volume increases significantly due to the different physical properties of water and steam. The density of liquid water is much higher compared to that of steam. Under standard conditions, 1 pound of water occupies about 0.12 cubic feet. In contrast, 1 pound of steam occupies approximately 27 cubic feet. This drastic increase in volume is commonly cited as being over 1600 times greater. This remarkable expansion occurs because steam, being a gas, has molecules that are much farther apart than in liquid water. The change from a liquid to a gas dramatically increases the spacing between the molecules, leading to a substantial increase in volume. Understanding this principle is vital for those working with boilers and steam systems, as it impacts pressure calculations and the design of piping systems, ensuring safety and efficiency in operations.