Designed to prevent sludge accumulations, submerged rotary jet mixer (SRJ) directs powerful jets of oil that dissolves and re-suspends the accumulated sludge throughout the oil. SRJ breaks the sludge of the boffom of the storage tanks into small pieces after which the sludge is decomposed and dissolved in the crude oil while the sludge floats up. Since tank sludge can accelerate corrosion, reduce storage capacity and disrupt operation selecting a proper tank cleaning method is essential. Among different methods of tank cleaning, SRJ is a reliable and cost-effective method that greatly reduces the personnel exposure risks and hazards without the need to vent the tank or remove it from service. In this technology, liquid is pumped from the bottom of the tank then directs with higher pressure within the tank through a rotary nozzle. In many applications, the submerged rotary jet mixer provides the fastest and most efficient mixing results. JDEVS as a pioneer designer and manufacturer of SRJ in Iran fabricates difflerent type of srj to meet the tank cleaning requirements.