TCFP Plans Examiner Practice Test

Which of the following is not a commonly used foam proportioner for fixed systems?

1. Pressure Bypass System Proportioner

2. Balanced Foam Proportioner

3. Eductor Proportioner

4. Plumbing Proportioner

The correct answer is: Pressure Bypass System Proportioner

The pressure bypass system proportioner is not commonly used for fixed foam systems. Typically, fixed foam systems employ methods that directly integrate with the system's operation to ensure efficient foam application for fire suppression. The other types of foam proportioners mentioned—balanced foam proportioners, eductor proportioners, and plumbing proportioners—are more widely recognized and utilized in fixed foam systems. Balanced foam proportioners are designed to maintain a specific ratio of foam concentrate to water under a variety of flow conditions, ensuring consistent performance. Eductor proportioners work by utilizing the venturi effect, where water flowing through the eductor creates a vacuum that draws foam concentrate in, allowing for effective mixing. Plumbing proportioners, on the other hand, are integrated directly into water supply systems and operate based on pressure and flow rates, ensuring that the correct proportion of foam concentrate is mixed with water. Each of these systems plays a crucial role in delivering foam effectively in various conditions. The pressure bypass system, while useful in some applications, does not fit the conventional design and functionality associated with fixed foam systems, which is why it is not considered a commonly used option.