The Nozzle Sampling Valve is designed to give operators a portable sampling point that can be attached to any 2½" NST hydrant nozzle allowing for a quick and easy method of collecting chlorine residual samples directly from the hydrant. Utilizing this dedicated sampling valve provides a better means of collecting hand samples from the hydrant during circumstances when high flow flushes (blow-offs) are needed from the main nozzle (i.e. main breaks, flow tests, etc). Kupferle does not recommend using the product for collecting bacteriological samples from fire hydrants that drain to ground due to the possibility of cross-contamination from ground water. Order part #X66-Petcock-9700.