DEMONSTRATION OF CORROSION-RESISTANT RETROFIT SYSTEM TO UPGRADE FIRE HYDRANTS

摘要

There is a need in both the military and public sectors to upgrade existing, old-generation fire h ydrants w ith a ne w-generation s ystem w hich is corrosion-resistant and a lso he lps to prevent deliberate injection of chemical/biological contaminants into the drinking water systems. Unfortunately, it is very common for many hydrants to be internally severely corroded enough not to operate during the time that it is absolutely supposed to work—during a fire. This inoperability is because the older cold-rolled stems become corroded to such an extent that the firefighter is unable to open the hydrant's water valve. As part of the Army/DOD Corrosion Program, 90 old-generation corroded (and di fficult to open) fire hydrants of various brand names, models, and vintages are being upgraded with a new generation retrofit system at a major A rmy in stallation. T he in novative, but off-the-shelf product requires no e xpensive excavation and promises to be reliable, economical, and corrosion-resistant since the main component is manufactured of series 304 stainless steel. The s ystem b eing t ested is t he D avidson H ydrant S ecurity Device Anti-Terrorism V alve (hereinafter referred to only as ATV). It currently is marketed as a stealth check valve to reduce potential drinking water contamination, either accidental or intentional, because i t p revents the introduction of toxins or other materials into the drinking water via the fire hydrant. This demonstration project also is focusing upon the corrosion-resistant materials of the components, especially the series 304 stainless steel stem. The ATV consists of four main parts: insert seat, valve, a series 304 stainless steel machined stem, and a series 302 stainless steel spring. The ATV also prevents other hydrant vandalism, e.g., placement of foreign objects such as a rock, bottle, silt or tennis ball into the hydrant which could clog fire engine pumper screens or damage the impeller blades of the pump. Location of the ATV in a hydrant eliminates the need for fire department personnel to flow the hydrant prior to hooking it to the pumper, which saves valuable minutes at a working fire. The ATV is passive and requires no a ction on t he part of the fire department other than what normally is required to turn on the hydrant. Thus the ATV is a low-maintenance device which exposes potable water to no new materials other than those currently used in hydrants.