How Does Pressure Relief Work on Your Working Fire Nozzle?

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What is the Working Fire Nozzle? 

This unique nozzle is a fixed flow firefighting nozzle with pressure relief. The Working Fire is available as a 150 at 75 or 160 at 50 nozzle. It provides revolutionary performance when you need maximum flow. Whether you are over pumping the nozzle or receiving an increase of GPM from a gated wye operation, the nozzle’s pressure relief feature dramatically limits your nozzle reaction.