Firefighting Equipment: Foam Proportioners Explained
What is the most common apparatus-mounted foam proportioner that consists of a small return (bypass) water line connected from the discharge side of the pump back to the intake side of the pump?
a. Around-the-pump proportioner
b. Bypass-type balanced pressure proportioner
c. Variable-flow variable-rate direct injection proportioner
d. Variable-flow demand-type balanced pressure proportioner
Final answer: The most common apparatus-mounted foam proportioner with a small return or bypass water line from the pump's discharge side to the intake side is the Around-the-pump proportioner.
Answer:
The most common apparatus-mounted foam proportioner that consists of a small return or bypass water line connected from the discharge side of the pump back to the intake side of the pump is the Around-the-pump proportioner. It is widely used because it effectively injects foam into the water flow, aiding in fire suppression.
Explanation:
The most common apparatus-mounted foam proportioner, known as the Around-the-pump proportioner, works by utilizing a small percentage of the total water flow. This device has a small return or bypass water line connected from the discharge side of the pump back to the intake side. Typically, around 3 to 6 percent of the water flow is circulated through the proportioner, where the foam concentrate is injected into this bypass flow. The foam solution is then returned to the pump, effectively aiding in fire suppression.