They are used portably for water washing, or fixed-in-place crude oil washing of small and medium size tanks and for cleaning hard-to-reach surfaces in large tanks. They can operate in any position by the Full-sphere with 360o coverage washing pattern. SK and SSK Machines: The SK and SSK machines both weight 30 kilograms (66 pounds) and are identical except for the SSK’s larger nozzle and great capacity. The SSK (only used for fixed-in place installations) has a maximum capacity of 75 cubic meters per hour and a cleaning range of 25 meters (82 feet). The SK has a maximum capacity of 53 cubic meters per hour and a cleaning range of 21 meters (69 feet). The wash cycle times for both units run from 17 to 32 minutes with inlet pressure of 5.25 to 12 kilograms per square centimeter (75 to 175 psi).