Double suction configuration, balance axial force automatically in the operatin. Separate structure of the screw and the shaft save the repairing and manufacturing cost. Seal: According to working condition and medium, adopt the following types of seals. Single mechanical seal with naturally aspirated protecting system. Double mechanical seal with forced circulating protecting system designed specially. Special sort bearing span reduces screws scratch. Increases the seal life and bearing life. Makes operating safety. Specially designed screw improves pump efficiency. Designed according to API676 standards Specially designed configuration, increase the allowable dry running time. Even if the inlet GVF ranges rapidly between 0 and 100% pump runs normally.