Red Seal Gasfitter — Class A Practice Exam

What is the maximum allowable pressure for a residential gas supply line?

1. 2 psi

2. 5 psi

3. 10 psi

4. 15 psi

The correct answer is: 5 psi

In residential applications, the maximum allowable pressure for a gas supply line is typically set at 5 psi. This standard is in place to ensure safe operation and to prevent damage to appliances and piping systems that are designed for low-pressure gas service. Higher pressures can increase the risk of leaks and can exceed the specifications of most residential appliances, which are generally designed to operate at much lower pressures (usually around 0.5 to 1 psi for natural gas). Understanding the importance of maintaining appropriate pressure levels is essential for gasfitters to ensure the safety and efficiency of residential gas systems. Adhering to these pressure limits helps to ensure compliance with manufacturer specifications and applicable codes, ultimately promoting the safe use of gas within homes.