The EWT-40 Self-Loop Well-Flushing Truck is a truck mounted unit for flushing of oilfield water injection wells. It is designed with functions of circulating well washing under pressure and on-line backwashing, featuring easy operation and excellent performance. This product is used for treatment of the returned fluid from the water injection wells, removing suspended solids, Oils and other pollutants, and reinjecting it into the water wells for closed-cycle well flushing.