What is the capacity of an EFRS 2-stage pump?

• A. 1890
• B. 1817
• C. 1134
• D. 1442

Answer: (A)

Capacity is the pump’s maximum discharge rate, the highest amount of water it can move per minute under standard test conditions. In a two-stage pump, two impeller stages allow you to deliver a large flow at lower pressure, then maintain pressure as demand increases, which means the flow will drop as head rises.

For the Edmonton Fire Rescue Services 2-stage pump, the published maximum discharge is 1890 litres per minute. This value represents the pump’s rated capacity at low-head conditions. When you increase head (more friction loss, higher discharge pressure, longer hoses), the actual flow drops below that maximum. The other numbers are not the pump’s rated maximum; they reflect different operating points or configurations.