46.66.00 Ultraviolet Equipment
46.66.53 Open-channel Low-pressure/Low-intensity Ultraviolet Treatment Equipment
46.66.13 Closed-vessel Low-pressure/Low-intensity Ultraviolet Treatment Equipment 46.66.16 Closed-vessel Low-pressure/High-intensity Ultraviolet Treatment Equipment 46.66.23 Closed-vessel Medium-pressure Ultraviolet Treatment Equipment 46.66.53 Open-channel Low-pressure/Low-intensity Ultraviolet Treatment Equipment 46.66.56 Open-channel Low-pressure/High-intensity Ultraviolet Treatment Equipment 46.66.63 Open-channel Medium-pressure Ultraviolet Treatment Equipment