How many GPM are the proportioning pumps rated at?

How many GPM are the proportioning pumps rated at?

• A. 60-70 GPM
• B. 50 GPM
• C. 65 +/-5 GPM
• D. 75 GPM

Answer: (D)

Proportioning pumps are designed to deliver a precise amount of foam concentrate each minute so the concentrate-to-water ratio stays correct as the water flow through the system changes. For this transfer station setup, the standard rating of the proportioning pumps is 75 gallons per minute. That fixed rate ensures enough concentrate is metered in across the expected operating flows to produce the proper foam blanket; lower ratings would under-feed concentrate during heavier water flow, compromising foam quality. A range like 60–70 GPM or a 65 ± 5 GPM spec implies less than the standard 75 GPM and variability that isn’t used in this design, so 75 GPM is the correct, consistent rating.

Proportioning pumps are designed to deliver a precise amount of foam concentrate each minute so the concentrate-to-water ratio stays correct as the water flow through the system changes. For this transfer station setup, the standard rating of the proportioning pumps is 75 gallons per minute. That fixed rate ensures enough concentrate is metered in across the expected operating flows to produce the proper foam blanket; lower ratings would under-feed concentrate during heavier water flow, compromising foam quality. A range like 60–70 GPM or a 65 ± 5 GPM spec implies less than the standard 75 GPM and variability that isn’t used in this design, so 75 GPM is the correct, consistent rating.