With the water pumping from a strong hydrant, how many pumpers may be supplied?

• A. Two
• B. One
• C. Three
• D. Four

Answer: (B)

When a pumper is drawing water from a hydrant, the hydrant’s pressure and the suction needs of the pumpestablish a limit on how many engines can be fed directly. Even a “strong” hydrant can deliver ample flow, but feeding more than one pumper at the same time splits that flow and can drop the pressure at the pump’s intake below what is needed to maintain prime and prevent cavitation. So, the safest and most reliable setup is to supply only one pumper directly from a hydrant. If more pumpers are required, use a relay or another hydrant to feed additional engines rather than trying to feed multiple pumpers from a single hydrant at once.