Vertical Axial Flow Pump Unit

The ZLB type pump is a single-stage vertical axial flow pump, with the liquid flowing along the pump shaft axis. This type of water pump has low head and high flow rate, suitable for transporting clean water or other liquids with similar physical and chemical properties to water. The temperature of the liquid to be transported is 50°C. It is mainly used for agricultural irrigation and drainage, industrial thermal power plant circulating water supply, urban water supply and drainage, shipyard water level rising and lowering, or other water conservancy projects, with a very wide range of applications.

The pump shaft is made of carbon steel and is supported by two rubber (or plastic) bearings at the top and bottom. During operation, it provides an excellent condition for lubricating the bearings with water. The upper bearing on the pump shaft, being mostly above the water level, is equipped with a short pipe on the stuffing box (or seal cover) for the purpose of introducing clean water to lubricate the bearing before starting (water supply can be stopped after the pump starts and water is discharged). The bearing neck is a carbon steel sleeve, coated with hard chrome to enhance wear resistance and corrosion resistance. Other main components such as the bell mouth pipe, impeller seat, impeller housing, guide vane body, bearing housing, elbow pipe, stuffing box, and coupling are all made of cast iron. The stuffing box is fitted with packing to improve the pump's sealing. The rotation direction of the pump impeller, viewed from the suction inlet, is counterclockwise (when viewed from top to bottom, it is clockwise).

The impeller housing (or attached to the guide vane body and the inlet bell) and the two adjacent surfaces of the impeller are both spherical, ensuring that there is minimal clearance between the outer circumference of the impeller and the housing at any installation angle, thereby reducing the water loss from backflow.

According to operational requirements, this type of pump can be adjusted for increased or decreased speed by referring to the "Performance Table," or by altering the blade installation angle to change flow rate and head, thereby expanding its application range. The blades are made of cast iron, and all impellers are statically balanced before shipment. The blades are secured to the impeller seat with blade nuts (or blade clamps), and angle lines are etched on the adjacent surfaces of the blade and impeller seat. At the time of shipment, the blade installation angle is typically set at "zero" degrees. Users can adjust the blade installation angle according to the Performance Table as needed. Before installation, users must retighten the blade nuts once more to prevent loosening and potential accidents.