Gas Fitter Practice Test

At what pressure does natural gas become a liquid under typical conditions?

1. 10 psi

2. 150 psi

3. 300 psi

4. 500 psi

The correct answer is: 300 psi

Natural gas begins to condense into a liquid when subjected to increased pressure and lowered temperatures. Under typical conditions, natural gas is primarily made up of methane, which requires significant pressure to transition from its gaseous state to a liquid state. The correct answer indicates that around 300 psi is generally the pressure required to achieve liquefaction in most common scenarios, particularly when considering ambient temperatures. The liquefied natural gas (LNG) process typically takes place at pressures in this range under standard operational conditions. This capability to liquefy natural gas is crucial for storage and transportation, as liquid natural gas occupies much less volume than gaseous natural gas, making it a more efficient means of transport over long distances. The other pressure values listed would not achieve the same liquefaction effect under typical conditions, as they either fall short of the necessary pressure or exceed it without being necessary for the phase change from gas to liquid.