Red Seal Gasfitter — Class B Practice Exam

What is the ideal gas pressure range for most residential systems?

1. 1 inch to 3 inches of water column

2. 5 inches to 14 inches of water column

3. 15 inches to 30 inches of water column

4. 10 inches to 20 inches of water column

The correct answer is: 5 inches to 14 inches of water column

The ideal gas pressure range for most residential systems typically falls between 5 inches to 14 inches of water column. This range ensures that gas appliances, such as furnaces, water heaters, and stoves, receive a consistent and safe gas supply for optimal performance. Within this range, appliances can operate efficiently while minimizing the risk of issues like improper combustion or gas leaks. The lower limit of 5 inches is often sufficient for many residential appliances, while the upper limit of 14 inches allows for the proper functioning of larger or more demanding systems. Maintaining gas pressure within this specified range is crucial for safety and efficiency, as pressures that are too low may lead to inadequate fuel delivery, while pressures that are too high can cause damage to appliances and increase the risk of hazardous conditions. Understanding this pressure range helps gasfitters ensure that installations are compliant with relevant codes and manufacturer specifications, providing safety and reliability for residential gas systems.