Large scale water supply operations involving fire hydrants require the ability to maximize a fire department pumper's access to the available water. This generally means taking in water from every available hydrant outlet nozzle and using LDH whenever possible. A typical set-up, called a "heavy water hook-up" in some areas of the country uses some type of "hydrant assist" valve on the main outlet nozzle and a ball (or gate) valve on the two auxiliary outlets (often 2-1/2")

When expecting large fire flow needs, take that extra minute or two to gain access to ALL hydrant outlets.