California ICC UST Inspector Practice Exam

What is true regarding the use of flow restrictors on vent piping after October 1, 2018?

1. They meet positive shut-off requirements

2. They do not meet positive shut-off requirements

3. They can be approved by the local agency

4. They require no modifications

The correct answer is: They do not meet positive shut-off requirements

The correct answer pertains to the functionality of flow restrictors in vent piping, particularly regarding their compliance with positive shut-off requirements. After October 1, 2018, it was established that flow restrictors do not provide positive shut-off capabilities. Positive shut-off is critical because it prevents the possibility of fuel leaks during a pressure release scenario, enhancing both environmental safety and compliance with regulatory standards. Flow restrictors are designed to limit the flow of vapors or liquids; however, they do not completely stop the flow when needed, which is the crucial characteristic required for a positive shut-off mechanism. This differentiation is vital for ensuring that vent systems can effectively manage overpressure without releasing hazardous materials into the environment. Understanding this ensures that inspectors and those involved in regulatory compliance recognize the limitations of flow restrictors and emphasize the need for additional safety mechanisms that can provide the necessary shut-off features in vent piping systems.