Modern hydrants Valves include design features not found in the early designs, most intended to make them easier to operate or maintain and to extend their service lives. For instance, oiling systems using food grade oil, grease chambers and plastic thrust washers make the operating nut easier to turn.

Cast iron remains the most common material for fire hydrants, but ductile iron is also used. Water works brass, also referred to as bronze, is used in many of the parts associated with the main valve and drain valve areas, and for the nozzles. O-rings have replaced adjustable packings for longer life and maintenance-free sealing of parts.

Because hydrants are usually located on street curbs and vulnerable to being struck by vehicles, most modern hydrants include a break-away feature. Parts at strategic points, usually just above the ground surface, are designed to fail in a predictable manner when subjected to collision forces. These parts allow the upper part of the hydrant to separate cleanly from the buried portion, and the hydrant to be reset easily.

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